HTML and CSS Tutorial

Chapter 1: Getting Started

Welcome to the world of HTML! If you have never written HTML code before, you should start

with this section. If you’ve written HTML before, you should feel free to skip ahead to Chapter 2 ,

Markup Basics.

When you’re done with this chapter, you should be able to:

• create and alter a simple web page

• explain what HTML elements and attributes are

• use your browser to help you view and reuse code from other websites

Section Summaries

The Getting Started chapter contains these sections:

1. Diving In — Demonstrates basic HTML concepts by diving in and creating a simple web

page.

2. Structure — Examines document structure: the html element, the head, the title, and

the body.

3. Tinkering — Makes alterations to the “Simple Web Page”. We’ll add text, change the

background color, and explore how HTML handles whitespace.

4. Elements — Explores elements, which are the basic building blocks of a web page. What are

the components of a element? What happens if you misspell a element? And is there a good

use for the blink element? The answer might surprise you!

5. Attributes — Explores attributes, which modify the behavior of a element. We’ll look at the

components of an attribute and talk about attribute whitespace, attribute misspellings, and

other issues.

6. Browser Tools — Explains how to use key browser features, such as viewing source,

viewing page properties, and saving images.

Diving In

The first thing we’re going to do is dive in and create a simple webpage. We’ll explore what’s going

on soon, but for now, just follow the directions as best you can.

To create your web page, you need:

• A browser (you’re using one right now)

• A plain text editor (you already have one on your machine)

Step 1: Open a Text Editor

A text editor is a program that edits plain text files. When authoring HTML, do not use Word,

Wordpad, Pages, or any other program that does not save files as plain text.

• Windows users: open Notepad ( Start | Programs | Accessories | Notepad )

• Mac OS X users: open vi or TextEdit ( Applications | TextEdit )

• Linux and other UNIX users: open vi or emacs

Unfortunately, Notepad and TextEdit are not very good text editors. By default, Notepad always

tries to save and open files with a .txt extension. You must constantly fight with it to make it save

and open webpages (files with a .htm or .html extension). Be strong, and ye shall overcome.

Likewise, TextEdit does not use plain text by default. Before using TextEdit to edit HTML, go into

Preferences and set the Format for new documents to be Plain Text. For good measure, you might

have to convert your existing document to plain text ( Format | Make Plain Text ).

Using Notepad to write HTML is kind of like using a butter knife to cut a birthday cake — it’s the

wrong tool for the job. A better choice would be a more advanced text editor, such as:

• Crimson Editor (Windows, free)

• Smultron (Mac OS X, free)

• TextMate (Mac OS X, not free, but well worth the money)

• jEdit (Cross-platform, free)

All of these editors avoid the problems with file extensions and plain text described above, and have

numerous extra features for advanced users. You don’t have to download one of these editors right

now, but if you continue with web development, you’ll need to upgrade your tools.

Step 2: Create and Save the Web Page

Copy-and-paste the text in Example 1.1, “A Simple Webpage” into your text editor, starting with the

text, "<html>".

Example 1.1. A Simple Webpage

1. <html>

2. <head>

3. <title>A Simple Webpage</title>

4. </head>

5. <body>

6. This is a simple webpage.

7. </body>

8. </html>

To see what this HTML code sample looks like as a web page, click the view html link above the

code sample.

The words that are surrounded with angle brackets (< >) are called elements. We will talk about

what a element is soon, but first let’s finish creating and displaying your webpage.

Once you have copied the text over to your text editor, save the file in your home directory or

Desktop as the file simple.html.

Note

Notepad will try to append a .txt extension to your file name. Don’t let this happen. In the Save

As dialog box, set File name to simple.html and change Save as type from Text Documents to

All Files (*.*).

Step 3: Display the Webpage in Your Browser

Open the file simple.html by typing Ctrl-O (Cmd-O for Mac users) and selecting the file.

Internet Explorer users should select Browse to find the file.

After selecting simple.html, click Open. Your webpage should appear in the browser window.

If it does, congratulations! Let’s move on to the next section, where we’ll try to answer the question,

what the heck is going on?

Structure

The previous section demonstrates how to create a simple web page. If you haven’t saved this

example on your computer as the file simple.html, do so now.

Example 1.2. A Simple Webpage

1. <html>

2. <head>

3. <title>A Simple Webpage</title>

4. </head>

5. <body>

6. This is a simple webpage.

7. </body>

8. </html>

If you view simple.html in your browser, you will see the words “This is a simple webpage” on

a white or grey background. Where did everything else go? And what are those words with the

angle brackets, anyway?

A Brief Introduction to Elements

The web page simple.html uses these elements: html, head, title, and body.

• Elements are delineated by angle brackets (< >).

• Elements are “invisible”; they don’t directly appear in the web page. Instead, they serve as

instructions to your browser. They can change your text’s appearance, create a link, insert an

image, and much more.

• An element starts with an opening tag (<element>) and ends with a closing tag

(</element>). Some elements do not require closing tags.

We’ll discuss the general properties of elements in some detail in Elements. For now, let’s focus on

the particular elements in the “Simple Webpage” example.

Structure of the Simple Webpage

Although the “Simple Webpage” doesn’t look like much, its elements (html, head, title, and

body) are fundamental to the structure of all HTML documents. Here’s what these elements mean:

• <html>: “Here begins an HTML document.”

The html element helps identify a file as an HTML document.

• <head>: “Here begins the header.”

The header contains elements that apply to the overall document. For example, it might

contain elements that are designed for search engines to process or elements that change the

overall appearance of the webpage. However, elements in the header do not display directly

as normal webpage content.

The reasons you would be concerned about the header are a bit abstract at this stage, so we

won’t worry about it much until later.

• <title>: “Here begins the document title.” (Must be in the header)

If you view the file simple.html in your browser, along the top of your browser window

you should see the words, “A Simple Webpage”. These words appear because of the title

element.

As an exercise, change the title of the simple.html webpage to, “My First Webpage”.

Save your changes and view them by clicking the browser’s Refresh or Reload button.

Titles might not seem important at first glance, but they’re actually quite useful. For

example, if a search engine displays your page in a list of search results, it will probably

display the title as your page’s title. If you omit the title element, the search engine

will make up one for you. This is Not a Good Thing.

Note

You might have noticed that the title element is contained within the head element. Is

this kosher? Absolutely! In fact, many elements are designed to contain other elements, and

you will be nesting elements within other elements quite frequently as you continue.

• <body>: “Here begins the body.”

The body is where you put text and elements to be displayed in the main browser window.

The reason that the words “This is a simple webpage” appear when you display

simple.html is becaused you placed them in the body.

So why do we only see “This is a simple webpage” when we display simple.html in a browser?

The answer is, after you remove all the elements that are not designed to display in the browser

window, the sentence “This is a simple webpage” is the only thing left.

In the next section, we’ll tinker with our example webpage, just to see what happens. After that,

we’ll provide a more formal definition of elements and element properties.

Tinkering

Let’s make a few alterations to our “Simple Webpage” from “Diving In”.

Example 1.3. Adding Text

1. <html>

2. <head>

3. <title>A Simple Webpage</title>

4. </head>

5. <body>

6. This is a simple webpage.

7. And I mean really simple.

8. </body>

9. </html>

To view this alteration:

1. Add the text in bold to your simple.html file.

2. Save the file as adding.html.

3. Open the adding.html file in your browser.

HTML and Whitespace

What happened here? Why are the two sentences on the same line?

HTML ignores whitespace (spaces, tabs, or carriage returns) in the source. It replaces all continuous

chunks of whitespace with a single space: ” “. Although it might take you a while to get used to this

behavior, the advantage is that that you can use whitespace to make your code more readable, and

the browser can freely adjust line breaks for each user’s window size and font size.

Example 1.4, “Scattered Text” displays in the browser identically to Example 1.3, “Adding Text”.

Try it out.

Example 1.4. Scattered Text

1. <html>

2. <head>

3. <title>A Simple Webpage</title>

4. </head>

5. <body>

6. This is a

7. simple webpage.

8. And I

9. mean

10.

11. really simple.

12.</body>

13.</html>

Note

For brevity, subsequent examples will leave out the html, head, title, and body elements,

since we’re just changing the body content. If the head content becomes important again, we’ll

add it back.

Of course, HTML provides many ways to control whitespace. For a couple of simple examples,

refer to “Paragraph Breaks”.

Emphasizing Text

Now change the text of your simple web page to:

Example 1.5. Emphasized Text

1. This is a simple webpage.

2. And I mean <em>really</em> simple.

Save your changes and view the file in your browser.

As you can see, the text becomes italic, starting at the <em> and ending at the </em>. The em

element represents emphasized text — text that you would stress when speaking. The em element is

our first example of an element that can affect the physical appearance of the text.

For more examples of elements that can affect the appearance of text, refer to “Font Styles”.

Changing the Background Color

Let’s do something a little more dramatic:

Example 1.6. Background Color

1. <html>

2. <head>

3. <title>A Simple Webpage</title>

4. </head>

5. <body style="background: yellow">

6. This is a simple webpage.

7. And I mean <em>really</em> simple.

8. </body>

9. </html>

A bit garish… but things could be worse. Try background: red, for example.

This is our first example of an attribute, a component of an element that modifies that element’s

behavior. For some elements, like the body element, attributes are optional. For other elements,

attributes are essential. We’ll discuss attributes at some length later, in “Attributes”.

Try some other color words: blue, teal, limegreen, papayawhip… What works? What

doesn’t? (If you’re interested, feel free to skip ahead to the section called “Colors”.)

Elements

After all this experimenting with our example webpage, it’s time to define elements more formally.

Elements have three main components:

1. <name attribute1="value1" attribute2="value2"...>

2. ...(text or more elements go here)...

3. </name>

• name: Identifies the type of the element, such as body or em element. The name of an

element can be upper case, lower case, or anything in between. Upper case makes it easier to

differentiate elements and text when examining HTML source, while lower case is a more

modern style and is easier to type. Either way, it’s a matter of taste: <BODY>, <body>, and

even <bODy> are all the same element.

• attribute: Changes the behavior of an element. For example, the style attribute

enables you to change the appearance of an element and its content.

• value: Enables particular attributes to vary. For example, background: yellow,

when present in an element’s style attribute, changes the background of the element to

yellow.

Some elements do not require a closing element to work properly. For example, the br element

creates a line break, and should not enclose anything. We’ll discuss br further in “Paragraph

Breaks”.

Some elements do not require any attributes. In “Example 1.6, Background Color”, the body

element had a style attribute, but the body element works just fine without without it. By

contrast, the a elemen t, which creates a hyperlink, has an href attribute that defines the link’s

destination. If you don’t include the href attribute, the link won’t point anywhere.

Misspellings and Misunderstandings

Vastly simplified, a browser processes an HTML page something like this:

1. Identify anything that is between angle brackets (< >) as a “element”

2. Determine whether the browser has any instructions for using the element:

• If yes, the element is real — follow the instructions

• If no, the element is garbage — ignore it

When a browser ignores a element, that means one of two things:

• The element is misspelled or does not exist. For example, mxyzptlk, for example, is not

an HTML element.

• The element means something, but that particular browser does not support it. For example,

the blink element works in Firefox, but not in Internet Explorer or Safari.

Example 1.7. Blinking Text

1. Warning: <blink>For external use only</blink>.

2. Avoid contact with eyes.

If you are using Firefox, the text in the “view html” box should be blinking. If you are using

Internet Explorer or Safari, the text will not be blinking. This is actually a common situation when

composing web pages — one browser won’t support a particular feature, or supports it incorrectly.

Caution

Most people find the blink element distracting and irritating, and in fact blink is not part of the

official HTML standard. In fact, I am aware of only one example of a good use of blink on the

entire Web. Well, maybe two.

A Digression: What’s a “Tag”?

You’ll often hear people refer to “tags,” as in, “The markup tags tell the Web browser how to

display the page.” Almost always, they really meant to say “elements.” Tags are not elements, they

define the boundaries of an element. The p element begins with a <p> open tag and ends with a

</p> closing tag, but it is not a tag itself.

• Incorrect: “You can make a new HTML paragraph with a <p> tag!”

• Correct: “It’s a good idea to close that open <p> tag.”

Sometimes you’ll hear people say “alt tag,” which is even worse. An “alt tag” is really an alt

attribute. This important attribute provides alternative text for images, in case the user can’t see the

image for some other reason. We’ll talk more about this attribute later.

The element vs. tag confusion is sort of understandable: it’s a common mistake even among

professionals, and they both look like angle-brackety things, after all. But attributes are not tags, not

even close. If you hear someone say “alt tag,” this is a key indication that the speaker does not

understand HTML very well. (You probably shouldn’t invite them to your next birthday party.)

Attributes

Attributes modify the behavior of a element. Attributes allow you to change sizes, colors, specify

link locations, and much more. They have two main components:

1. <name attribute1="value1" attribute2="value2" ...>

2. ...(text or more elements go here)...

3. </name>

• attribute: Defines the attribute that you’re using. As with elements, case is irrelevant for

the attribute name. STYLE, style, and sTyLE all do the same thing.

• value: Selects a particular kind of behavior for the attribute. Case sometimes matters for

the values inside of the attribute, so be careful here.

“Changing the Background Color” includes an example of using the style attribute to control the

background color of the entire webpage. Here’s a second example, the href attribute:

Example 1.8. A Link to The New York Times

1. <a href="http://www.nytimes.com">go to nytimes.com!</a>

The a element (or, “anchor” element) creates a link to another web page. The href attribute

specifies the location, which we set to the value http://www.nytimes.com. If you view the

results and select the link “go to nytimes.com!”, you will indeed go to the New York Times.

Note

The style and href attributes are very different beasts. The style attribute is optional, and

may be applied to nearly any HTML element in the body. The href attribute is essential for

specifying a link location, and only applies to a narrow set of elements.

Attribute Properties

Attributes follow these rules:

• Elements may have multiple attributes. The order of the attributes is irrelevant.

• Each element has a list of permitted attributes. Some attributes may be assigned to most (or

even all) elements. But in general, you cannot freely add any attribute to any element.

• Whitespace between attributes is irrelevant. You may freely insert spaces, tabs, or even

carriage returns between attributes, as long as you don’t forget the closing angle bracket at

the end of the element (>).

For example:

1. <a href="http://www.gutenberg.org"

2. style="background: yellow"

3. >Books in the public domain</a>

is perfectly acceptable. For elements with many attributes, adding whitespace can sometimes make your code more readable.

• Although upper case and lower case is irrelevant for attribute names, the case can be

important for attribute values.

For example,

1. <a href="http://www.cnn.com/index.html">Go to CNN</a>

creates a link that takes you to the CNN.com home page, while

1. <a href="HTTP://WWW.CNN.COM/INDEX.HTML">Go to CNN</a>

is a broken link.

• It is good practice to quote attribute values, although often this is optional. That is,

href=http://www.yahoo.com is the same as

href="http://www.yahoo.com". If the attribute value contains a special character

such as a space or an angle bracket (< >), you must use quotes, or the browser will interpret

the special character as the end of the attribute or element.

Caution

Take care to close any open quotes you start. Otherwise, your attribute value will “continue”

until the next quote mark, which will badly garble your page.

• As with elements, browsers attempt to ignore incorrect attributes. Misspelled attributes and

attribute values, such as hhref and backgrounde: yellow, have no effect.

Misspelling background means that your background won’t turn yellow. Misspelling

href means that your link won’t function. However, if you misspell

http://www.yahoo.com, your link will function, but it won’t take you to the right

place.

Browser Tools

A browser’s primary function is to display web pages. However, for a web developer, browsers are

much more useful than that. Whenever you visit a web page, your browser fetches a tremendous

amount of valuable information, such as the HTML source of the page, image files that appear on

the page, and other associated files. This section describes how to use your browser to retrieve that

information.

Note

Since browser makers love to change the names and locations of these functions from version to

version, the instructions below might not apply if you’re using a different browser version than the

one tested at the time this section was written.

View Source

By far the most valuable browser tool is View Source, which displays the HTML source of the

page. Viewing source is one of the fastest ways to learn how to code. If you’re not sure how some

feature of HTML works, you can view the source of a site that uses the feature, copy and paste

sections of code, make alterations, and see what happens. To view source:

• Internet Explorer, Firefox: Right-click on the window and select View Source.

• Safari: Ctrl-click on the window and select View Source.

• Opera: Right-click on the window and select Source.

Although viewing the source is incredibly useful, keep in mind these two caveats:

• It’s okay to copy and alter a site’s source for learning purposes on your home machine, but

don’t post any such material on your public website. This goes for both the text on the site

and the underlying code or design.

• Most sites on the web have terrible underlying code. Learning how to code by randomly

viewing websites is like learning how to compose verse by randomly reading poetry written

by kids. You might encounter some brilliant stuff… but the odds are pretty low. Never

assume that just because BigFamousWebsite.com coded their home page a certain way,

that this was the best way to do it.

Save Images

Another invaluable browser function is the ability to save image files. Every time your browser

visits a web page, it also downloads all the images that display on the page. You can save these files

and reuse them for educational purposes. To save an image:

• Internet Explorer: Right-click on the window and select Save Picture As…

• Firefox: Right-click on the image and select Save Image As… to save the image as a file,

View Image to view the image by itself in the browser, or Properties to view the image’s file

size and other properties.

• Safari: Ctrl-click on the image and select Save Image to the Desktop to save the image as a

file or Open Image in New Window to view the image by itself in the browser.

• Opera: Right-click on the image and select Save Image… to save the image as a file, Open

Image to view the image by itself in the browser, or Image properties to view the image’s

file size and other properties.

As with View Source, you should never take someone else’s images, altered or unaltered, and post

them on a public site unless you have permission. There are numerous free image repositories all

over the web, where you can get clip art, backgrounds, and photos that are either in the public

domain or offered under reasonably liberal licenses.

View Page Info

The View Page Info function provides secondary technical information about the page, such as the

page size in bytes and the text encoding. This information might not seem all that useful when

you’re first starting out, but it’s invaluable for more advanced coders. To view page info:

• Internet Explorer: Right-click on the window and select Properties.

• Firefox: Right-click on the window and select View Page Info.

• Opera: Select Tools | Appearance | Panels, check the Info checkbox, and click OK.

The information displayed varies from browser to browser. Firefox provides more useful

information than Internet Explorer, including a full list of all images on the page (with height,

width, and size in bytes). Opera takes an interesting approach: if you activate the Info panel, you

can view this information alongside each page you browse to. Opera also provides a shortcut (Ctrl-J) for displaying all the links on the page.

Webdev Toolbars

Several browsers offer some sort of “webdev toolbar”: a downloadable set of menus and options for

your browser that are specifically designed to help understand the structure of a webpage. Toolbars

can offer a dizzying array of useful functions, but as with View Page Info, they are probably more

useful for experienced web developers.

Toolbars

• Internet Explorer

• Firefox

• Opera

Chapter 2: Markup Basics

This chapter, covers some of the basic HTML elements and attributes in a systematic way. Each

section displays one or more short webpages, which we will alter several times to demonstrate how

various elements work. Before proceeding, you should be comfortable with the idea of saving

HTML to a file, altering it with a plain text editor, and viewing the results in your browser. If not,

please read Chapter 1, Getting Started and work through the examples until you are comfortable

with these concepts.

When you’re done with this section, you should be able to:

• create a document with headings, paragraphs, and line breaks

• change the text color and background color

• use physical styles and logical styles to change the appearance of your text

• display images and create links to other web pages

• understand more complex HTML elements that require nesting, such as lists

Section Summaries

The Markup Basics chapter contains these sections:

1. Paragraph Breaks — Describes the paragraph element and the line break element, including

a discussion of correct and incorrect usage.

2. Headings — Describes the heading elements. In this section, we’ll discover why it’s really

important to close your open tags properly.

3. Font Styles — Explores elements that help control the font. We’ll touch on the difference

between inline and block elements, and compare physical style elements versus logical style

elements.

4. Colors — Explains how to change the background and foreground color of an entire page, a

paragraph, or even a single word. We’ll see examples of color names and hex codes, and

we’ll discuss which method is preferable.

5. Links — Breaks down a URL into its constituent parts, explains relative links versus

absolute links, and provides examples of how to use IDs to link within pages.

6. Images — Describes what images are, how to embed them in a web page, how to stretch and

squash them, and how to “float” them with respect to the other content on the page.

7. Lists — Describes ordered lists, unordered lists, and definition lists. This is our first example

of elements that require nesting to function properly.

Paragraph Breaks

In Chapter 1, Getting Started , we covered some basic HTML concepts, including the fact that

HTML ignores whitespace. This seems a little crazy, doesn’t it? How can we do we compose a

readable webpage without everything collapsing into a single giant glob of text?

Let’s say we want our website to display some lines from an obscure playwright:

Example 2.1. Unformatted Text

1. <html>

2. <head>

3. <title>Macbeth: 1, Reckless Youngsters: 0</title>

4. </head>

5. <body>

6. MACBETH: My name's Macbeth.

8. YOUNG SIWARD: The devil himself could not pronounce a title

9. More hateful to mine ear.

10.

11. MACBETH: No, nor more fearful.

12.

13. YOUNG SIWARD: Thou liest, abhorred tyrant; with my sword

14. I'll prove the lie thou speak'st.

15.

16. [They fight, and young Seward is slain.]

17.

18. MACBETH: Thou wast born of woman.--

19. But swords I smile at, weapons laugh to scorn,

20. Brandish'd by man that's of a woman born.

21. </body>

22.</html>

Now, this is a perfectly acceptable web page. The html, head, title, and body elements are all

in the right places. In fact, this example is just like the “Simple Web Page” from Diving In, except

that the text is a little different.

There is one small problem, however. HTML collapses whitespace, which means that all our text

will collapse into a single paragraph and look something like this:

MACBETH: My name’s Macbeth. YOUNG SIWARD: The devil himself could not

pronounce a title More hateful to mine ear. MACBETH: No, nor more fearful. YOUNG

SIWARD: Thou liest, abhorred tyrant; with my sword I’ll prove the lie thou speak’st.

[They fight, and young Seward is slain.] MACBETH: Thou wast born of woman.– But

swords I smile at, weapons laugh to scorn, Brandish’d by man that’s of a woman born.

This is terrible! Let’s try to make this page more readable.

The p Element

The p element breaks text into paragraphs. Any text that you surround with a <p> and a closing

</p> becomes a separate block. Let’s see how this works. For brevity, we will start to leave off the

structural elements: html, head, and body.

Example 2.2. Paragraphs

1. <p>

2. MACBETH: My name's Macbeth.

3. </p>

4. <p>

5. YOUNG SIWARD: The devil himself could not pronounce a title

6. More hateful to mine ear.

7. </p>

8. <p>

9. MACBETH: No, nor more fearful.

10.</p>

11.<p>

12. YOUNG SIWARD: Thou liest, abhorred tyrant; with my sword

13. I'll prove the lie thou speak'st.

14.</p>

15.<p>

16. [They fight, and young Seward is slain.]

17.</p>

18.<p>

19. MACBETH: Thou wast born of woman.--

20. But swords I smile at, weapons laugh to scorn,

21. Brandish'd by man that's of a woman born.

22.</p>

Each block is followed by two line breaks. This is a good start!

Each paragraph is surrounded by an opening tag, <p>, and a closing tag, </p>. The p element is a

block element; it “does something” to a block of text. The browser must identify where the block

ends, so the <p> open tag needs a closing tag, </p>.

Unfortunately, many people take the p element to mean “make a new paragraph here” or “put two

line breaks here,” rather than “enclose this text and make it a paragraph.” And thus, you see a lot of

code that looks like this:

Example 2.3. Incorrect p Usage

1. Text Block 1: Blah blah blah... <p>

3. Text Block 2: Blah blah blah... <p>

5. Text Block 3: Blah blah blah...

What happens? (Try it.) Text Block 2 and 3 are paragraphs (the browser “inserts” a closing </p>

element right before each <p> element). Text Block 1 is not actually a HTML paragraph. However,

the page displays with two line breaks between each text block, which appears to result in the same

thing as doing it the proper way.

So what’s the big deal? Why not do it the “improper” way, and avoid typing all those </p> closing

tags? Well, later we’ll talk about how to use a technique called Cascading Style Sheets (CSS) to

control the appearance of all elements of a particular type. For example, you can use CSS to set all

your paragraphs to be red 12pt Times New Roman. But if you’re using p incorrectly, you’ll be in

for an unpleasant surprise, as many of your paragraphs (or rather, what you thought were

paragraphs) won’t get the proper style applied.

The br element

We still need to break up the dialogue into lines, as they appear in the original play. Now, we could

do this with the p element, but then all lines would be equally spaced. and so it wouldn’t be clear

which line belongs with which speaker. How do we get finer control… say, one line break?

Example 2.4. Line Breaks

1. <p>

2. MACBETH: My name's Macbeth.

3. </p>

4. <p>

5. YOUNG SIWARD: The devil himself could not pronounce a title<br>

6. More hateful to mine ear.

7. </p>

8. <p>

9. MACBETH: No, nor more fearful.

10.</p>

11.<p>

12. YOUNG SIWARD: Thou liest, abhorred tyrant; with my sword<br>

13. I'll prove the lie thou speak'st.

14.</p>

15.<p>

16. [They fight, and young Seward is slain.]

17.</p>

18.<p>

19. MACBETH: Thou wast born of woman.-- <br>

20. But swords I smile at, weapons laugh to scorn,<br>

21. Brandish'd by man that's of a woman born.

22.</p>

Unlike the p element, the br element does not enclose any other HTML. There is no such thing as a

closing </br> element. Also note that we don’t have to put a final br element on the last line of

each dialogue exchange. The <p> element will take care of the last line break for us. So now we’ve

separated each speaker with a new line.

How does this look? (Try it.) Now each line of dialogue is on its own line on the page. The lines are

considerably easier to read.

As with the p element, many web designers use br incorrectly. You’ll often see code that looks like

this:

Example 2.5. Incorrect br Usage

1. Text Block 1: Blah blah blah...

2. <br><br>

3. Text Block 2: Blah blah blah...

4. <br><br>

5. Text Block 3: Blah blah blah...

This code is even worse than the code in Example 2.3, “Incorrect p Usage” . None of the text blocks

are HTML paragraphs, which makes them difficult to style. If you want paragraphs, use p, not br.

In fact, there aren’t that many places where you want to force a line break with br. The most

common cases are:

• Song lyrics

• Lines of poetry

• Lines of dialogue

Aside from that, there are more elegant ways to control line spacing, such as using a p element and

adjusting the spacing using CSS. But that’s a later lesson.

Headings

So far we’ve covered paragraphs and line breaks… but in a long document, we probably want more

structure than that. How do we create section headings?

The h Elements

There are six levels of heading elements: h1, h2, h3, h4, h5, and h6. These block elements tell

the browser to set off the heading from the rest of the text. The h1 heading level is the most

important heading, while the h6 level is the least important.

Most browsers display headings in bold, with h1 the largest and h6 the smallest.

Example 2.6. Headings

1. <h1>Heading 1</h1>

3. <h2>Heading 2</h2>

5. <h3>Heading 3</h3>

7. <h4>Heading 4</h4>

9. <h5>Heading 5</h5>

10.

11.<h6>Heading 6</h6>

Like the paragraph element p, the heading elements are block elements. Each matched set of

heading elements creates a new block, automatically separated from other blocks with line breaks.

Mangled Headings

In “Paragraph Breaks”, we discussed the consequences of failing to close your open <p> tags. This

is even more important for heading elements.

Example 2.7. Mangled Heading and Text

1. <h1>STAVE I: MARLEY'S GHOST

3. MARLEY was dead: to begin with. There is no doubt

4. whatever about that. The register of his burial was

5. signed by the clergyman, the clerk, the undertaker,

6. and the chief mourner. Scrooge signed it: and

7. Scrooge's name was good upon 'Change, for anything he

8. chose to put his hand to. Old Marley was as dead as a

9. door-nail.

Whoops! If you view the resulting web page, you'll see that the h1 element’s oversized, bold font

has spilled over onto the rest of the text. The browser has no indication where the h1 element is

supposed to end, and so it interprets the h1 element as enclosing everything else on the page.

Let’s fix this by closing the open <h1> tag. We’ll put the text in its own HTML paragraph for good

measure:

Example 2.8. Proper Heading and Text

1. <h1>STAVE I: MARLEY'S GHOST</h1>

2. <p>

3. MARLEY was dead: to begin with. There is no doubt

4. whatever about that. The register of his burial was

5. signed by the clergyman, the clerk, the undertaker,

6. and the chief mourner. Scrooge signed it: and

7. Scrooge's name was good upon 'Change, for anything he

8. chose to put his hand to. Old Marley was as dead as a

9. door-nail.

10.</p>

The heading and paragraph are now properly separated.

Font Styles

The style elements provide a straightforward way to control the font. These elements fall into two

categories: physical styles and logical styles. The style elements provide only crude control over the

appearance of your text. For more sophisticated techniques, refer to “Font Control”.

Logical Styles

A logical style indicates that the enclosed text has some sort of special meaning. We’ve already seen

the em element , which indicates that the enclosed text should be emphasized (stressed when

spoken). The list of available logical style elements includes:

• em — Emphasizes text. Usually rendered as italic.

1. Please do <em>not</em> feed the monkeys.

• strong — Strongly emphasizes text. Usually rendered as bold.

1. <strong>WARNING:</strong> Never feed the monkeys

2. under any circumstances.

• cite — Indicates a citation or reference. Usually rendered as italic.

1. For more information, please refer to

2. <cite>The Dangers of Monkey Feeding, Vol 2</cite>.

• dfn — Indicates the defining instance of a term; usually applied when the term first

appears. Usually rendered as italic.

1. Monkeys have sharp <dfn>canines</dfn>, sharp pointy

2. teeth to bite you with.

• abbr — indicates an abbreviation or acronym, such as RADAR (RAdio Detection And

Ranging); also provides a title attribute that may contain the fully-spelled out version.

Hovering your mouse over the abbr>> causes many browsers to display a “tooltip” with

the contents of the title attribute. Rendering is inconsistent; some browsers display a

dotted underline, while others do nothing special.

1. In particular, beware of

2. <acronym title="Monkeys Of Unusual Size">MOUS</acronym>es.

• code — Indicates computer code fragments and commands. Usually rendered in a

monospaced font.

1. <code>10 PRINT "I LOVE MONKEY CHOW"<br>

2. 20 GOTO 10</code>

Wait — “Usually rendered as italic?” What does that mean? Shouldn’t em, cite, and dfn always

render as italic?

Well, not necessarily.

• By default, most browsers render em as italic. However, this is only a convention. Nothing

requires browsers to use italic, and in fact, some browsers (such as an text-to-speech

synthesis browser) might be completely unable to use italic.

• Although the default is italic, you can override this using CSS. For example, you could

specify that on your website, all em elements render as red and bold.

Okay… but why do em, dfn, and cite all render the same by default? If I want italic, why

wouldn’t you just use em and forget about the rest?

Well, sure, you could do that. However, using a richer set of elements gives you finer control. For

example, you could declare that emphasized text is red and bold, but all citations are green and

italic. You can also use logical style elements to extract more meaning out of a website. For

example, if you knew that a website uses the cite element consistently, you could easily write a

program to extract a list of citations. (But don’t obsess over that point; there are better ways to store

and consume this sort of information.)

The key point to remember is that a cite element is a citation, not a chunk of italic text. The italics

are just a useful side effect.

Inline vs. Block Elements

Unlike the paragraph and header elements, the style elements listed above don’t mark off a “block”

of text. The physical style elements are inline elements that perform their work without adding extra

line breaks:

Example 2.9. Inline vs. Block Elements

1. <p>

2. 1. This is a paragraph with a section of

3. <em>emphasized text</em> inside of it.

4. </p>

6. <em>

7. 2. This is a section of emphasized text with

8. <p>a paragraph</p> inside of it.

9. </em>

The first sentence results in one “block” with a couple of emphasized words inside. In the second

sentence, the p element breaks the text up into multiple blocks.

Physical Styles

Physical style elements specify a particular font change. For example, to make text bold, you can

mark it off with the b element: <b>bold text</b>. The list of available physical style elements

includes:

• b — Makes text bold. Appropriate for product names, …

1. Today, UniStellarDefenseCorp is proud to announce

2. <b>Neutrinozon</b>, the only neutrino-based death ray

3. on the market.

• i — Makes text italic. Appropriate for ship names, internal monologues and thoughts, …

1. This exciting new product has already been installed on many

2. advanced warships, including the <i>I.S.S. Hood</i>.

• sub — Makes text a subscript. Appropriate for scientific and mathematical notation, …

1. Although the standard electron neutrino (μ<sub>e</sub>)

2. configuration packs plenty of punch, muon neutrino

3. (μ<sub>ν</sub>) upgrades are available on request.

• sup — Makes text a superscript. Appropriate for footnotes, scientific and mathematical

notation, …

1. With an intensity of 1.76x10<sup>6</sup>

2. cm<sup>-2</sup>s<sup>-1</sup>, nothing can repel firepower

3. of this magnitude!

The physical styles are subtly different from the logical styles. The logical style element strong

means “something strongly emphasized,” while the physical style element b just means, “something

that is bold.”

A Digression: Physical Styles and Semantic Markup

These days, you’ll sometimes hear people claim that the physical styles are yucky and bad and

should never be used. This is because logical styles contain small quantities of a rare earth named

“Semanticism”. Semanticism can be mined and processed into the power source for farms of

spinning Academic Paper Turbines, which serve to feed and clothe members of our society who

would otherwise starve to death.

Although it is true that certain physical styles are obsolete, the i, b, sub, and sup elements are

appropriate to use in certain situations. For example, compare these code samples:

•

1. My grandfather served on the <i>U.S.S. Maine</i>.

•

1. My grandfather served on the <em>U.S.S. Maine</em>.

In this case, i is more appropriate than em, unless you think it’s appropriate to always be shouting

the “U.S.S. Maine” part. Not that i is all that wonderful, but em is just flatly wrong. Maybe it

would be nice if we had a vessel element, but HTML is a small language, and the i element is

the best we can do.

For a more extreme example, consider the quantity “2 to the x power,” represented in HTML as

2<sup>x</sup>. If we take away the superscript, this leaves us with 2x, which is most

emphatically not equal to “2 to the x power.” Even though the sup element literally means, “move

the 2 above the line”, this physical change to the text has actual mathematical meaning! (Thanks to

Jacques Distler for pointing this one out.)

Colors

“Changing the Background Color” briefly introduced how to change the background color to

yellow. That’s kind of neat, but this just raises more questions. If yellow is available, what are the

other colors I can use? Can I change the foreground color? Can I apply colors to just a small

selection of text?

Text (Foreground) Color

Here’s how to change the text color:

1. Add an attribute called style to the element. (<element style="">)

2. Inside the style attribute, specify the color you want by typing color: followed by the

color you want. (<element style="color: red">)

Note

As with all attributes, do not include the style attribute in the closing tag, </p>.

For example:

Example 2.10. Red Paragraph

1. <p>

2. The grandmother lived out in the wood, half a league from the village,

3. and just as Little Red-Cap entered the wood, a wolf met her. Red-Cap

4. did not know what a wicked creature he was, and was not at all afraid

5. of him.

6. </p>

7. <p style="color: red">

8. 'Good day, Little Red-Cap,' said he.

9. </p>

10.<p>

11. 'Thank you kindly, wolf.'

12.</p>

In the earlier example, Example 1.6, “Background Color”, the background of the entire page turned

yellow. But in our example above, the text turns red. A style attribute value of background:

sets the background color, while color: sets the foreground color.

Note

The keywords color and background are called CSS properties. CSS (Cascading Style Sheets)

is a technique for applying style to elements. Changing the element’s color is just one small

example of what CSS can do. We’ll learn a lot more about CSS in Chapter 3, Styling Basics , but for

now let’s focus on color specifically.

Background Color

To change the background color of a element, you just need to use a different property in the

style attribute: the background property. If you apply the background to the body element,

this changes the background color of the entire web page. (We saw an example of this in

“Tinkering”.) Not only can you change an element’s background color, you can change the text

color at the same time:

Example 2.11. Text and Background Color

1. <p style="background: yellow; color: purple">

2. There's a yellow rose in Texas, That I am going to see,<br>

3. Nobody else could miss her, Not half as much as me.<br>

4. She cried so when I left her, It like to broke my heart,<br>

5. And if I ever find her, We nevermore will part. <br>

6. </p>

The paragraph has two properties, background and color. When you apply multiple properties,

you can add them in any order, but you must separate them with a semicolon. If you forget the

semicolon:

1. <p style="background: yellow color: purple">

2. There's a yellow rose in Texas, That I am going to see,<br>

3. Nobody else could miss her, Not half as much as me.<br>

4. She cried so when I left her, It like to broke my heart,<br>

5. And if I ever find her, We nevermore will part. <br>

6. </p>

then the browser interprets this as setting the background color to the value yellow color:

purple. Since yellow color: purple is not a valid color, the browser does nothing (and

you might be left puzzling over why your styles aren’t appearing).

The results, Example 2.11, “Text and Background Color” are particularly garish and difficult to

read. This brings up an important point: it is very easy to go wrong when choosing text and

background colors. Use the color and background properties with caution.

Inline Color Styles

Although so far we’ve only applied the color properties to block elements such as body and p, you

may apply the color properties to inline elements as well, including the elements from “Font

Styles”. For example,

1. <p>

2. <strong style="color: red">DANGER:</strong> Flying monkeys.

3. </p>

The red color applies to the strong element, but not to the rest of the paragraph.

If you just want to change the color of a selection of text without also making it bold or italic, there

is a special inline element called the span element. The span element “does nothing” by default,

and so it is safe for applying styles without affecting anything else. We’ll discuss this element

further in the section “Div and Span”.

Note

Although you may apply the style attribute to a wide array of elements, there are some

exceptions. For example, you might think you can change the color of the title in your browser’s

title bar by adding a style attribute to the title element. However, this is invalid HTML, and

the browser ignores it.

In general, you may apply style to nearly any element that falls under body, including body itself.

Specifying Colors

In the previous examples, we were using color keywords such as red, green, and so on. What

other words are available? The answer it, it depends on your browser.

Here are sixteen color keywords that are nearly universal across all browsers that support color:

The numbers after the pound sign (#) are called hex codes. Hex codes are another way to represent

colors in HTML. It gets a little technical after this, so hang on…

Note

Those of you who grew up in the 1960s and experienced the “New Math” might have a small

advantage here. See, I bet you thought you’d never use that stuff again!

Hex Codes

Each of the six numbers in a hex code is a hexadecimal, or base-16 number.

• In the ordinary decimal system, each numeral (0-9) represents a power of ten. You need ten

symbols to represent decimal numbers: 0, 1, 2, 3, 4, 5, 6, 7, 8, and last but not least, 9.

With two decimal numerals, the highest number you can make is “99”. “9” in the tens place

+ “9” in the ones place = (nine x ten) + (nine x one) = 90 + 9 = 99.

• In a hexadecimal system, each numeral represents a power of sixteen, and so you need

sixteen symbols (0-9 and a, b, c, d, e, f). Here, a = 10 (decimal), b = 11 (decimal), and so on

up to f = 15 (decimal).

With two hexadecimal numerals, the highest number you can make is “ff”, which is 255 in

decimal notation. “f” in the sixteens place + “f” in the ones place = (fifteen x sixteen) +

(fifteen x one) = 240 + 15 = 255.

A color hex code consists of three two-digit hexadecimal numbers. Each number indicates how

much red, green, and blue the browser should display. The first hex number indicates how much red

to use, the second indicates the amount of green, and the third specifies the blue: RRGGBB. 00

means “use none of this color”, while ff means “use as much of this color as possible.”

Figure 2.2, “Hex Code #ff9933” demonstrates how this works. The hex code #ff9933 provides the

maximum amount of red, a middling amount of green, and a small amount of blue. Mixing the three

together results in an orange-ish color.

Here are some more examples:

• color: #ff0000 = All red, no green, no blue. Result: bright red.

• color: #00ffff = No red, all green, all blue. Result: bright teal (or “aqua”).

• color: #000000 = No red, no green, no blue. Result: black.

• color: #ffffff = All red, all green, all blue. Result: white.

• color: #cc99ff = A lot of red, some green, all blue. Result: lavender.

Hex codes can be uppercase or lowercase. Just don’t forget the pound sign at the beginning. There

are actually several more ways to specify colors, but color names and hex codes are the most

common.

Hex Codes vs. Color Names: Which is Better?

Hex codes are a bit harder to understand than color names, particularly if you’re not used to

hexadecimal notation. However, it’s probably better to use hex codes anyway.

First, hex codes provide much more flexibility — you can specify about 16 million different

combinations with hex codes. (Many computers can’t display that many colors, but that’s another

matter.)

Second, hex codes are more stable and universal. Simple color names such as “red” and “black”

will work in just about any browser, but support for fancy color names (“papayawhip”?

“eggshell”?) is a bit dodgier. It’s best to stick with hex codes, which work universally.

Links

Without hyperlinks, the Web wouldn’t be “the Web”. This section explains how to create links to

other websites (external links) and links within your own website (internal links).

The a Element

The anchor element, a, creates links. Here’s an example:

Example 2.12. External Links

1. <p>

2. A link to <a href="http://www.google.com/">Google's

3. home page</a>.

4. </p>

5. <p>

6. A link to

7. <a href="http://www.google.com/help/basics.html">a

8. page within Google</a>.

9. </p>

The syntax is straightforward: the href attribute indicates where the link should go, and the text

between the <a> and </a> tags becomes the highlighted link text.

Anchor Titles

The optional title attribute allows you to provide a little extra information about the link. Some

older browsers ignore this attribute, but most modern browsers produce a little floating “tooltip” if

you hover your mouse over the link.

Example 2.13. The title Attribute

1. Can physics be

2. <a href="http://www.dctech.com/physics/humor.php"

3. title="The most hilarious collection of physics

4. humor anywhere!">funny</a>?

5. Is that a rhetorical question?

You can use the title attribute to indicate where the link is going or provide some other useful

information. It’s nifty, but it doesn’t hurt to leave it out, either.

Components of the URL

To construct links to other websites, we need to understand the structure of the URL. Let’s take a

closer look at the URL “http://www.google.com/help/basics.html”:

• The protocol (“http://”): Specifies that we would like to use the HTTP (HyperText

Transport) protocol. This is the standard protocol for retrieving web pages, although there

are others, such as FTP (File Transfer Protocol) and HTTPS (Secure HyperText Transport

Protocol). Most of the time, though, you’ll be using “http://” to retrieve pages from external

sites.

You may specify the protocol in upper case, lower case, or anything in between, but most

people use all lower case.

• The website (“www.google.com”): This specifies that we would like to access a page

from google.com. More technically, it means:

1. Go to the top-level domain “com” (a collection of many millions of websites).

2. Within “com”, find the the domain name “google”.

3. Within “google”, find the the sub-domain named “www”.

Finding the website is similar to finding a mailing address. The address “1600 Pennsylvania

Avenue NW, Washington, DC 20500” means: go to the zip code “20500”; within “20500”,

find the city “Washington D.C.”; within “Washington, DC”, find the building “1600

Pennsylvania Avenue NW”.

As with the protocol above, you may use any case you like for specifying the website,

although most people use all lower case.

• The file path (“/help/basics.html”): This specifies that we would like to access the

file basics.html, which is inside the directory help/.

Unlike the other components, the filepath can be case-sensitive. Depending on the website

you’re visiting, the file Basics.html might be different from the file basics.html.

Wait, Which File Was That Again?

This is a little odd — in our first example, “http://www.google.com/”, we didn’t specify a file or a

directory. So what did we ask for, exactly?

First, it turns out the directory is specified. The single forward slash (“/”) represents the “root” or

“top-level” directory of the website. We’re asking Google to give us a file from the top directory of

its website.

Okay, but which file are we asking for? We didn’t specify the name of the file explicitly, we just

asked for a directory. This means means we’re asking Google, “Give us the default file for that

directory, if you have one.” As it turns out, Google is going to give us a file named “index.html”,

but the exact name could be anything. It’s up to Google.

Internal links

Internal links are similar to external links except that you can leave off the protocol and website

name. You only need to specify the file path.

File paths for internal links can be absolute or relative. Absolute links always begin with a forward

slash. They specify a path that starts at the root directory of your web server. Relative links never

begin with a forward slash. They specify a path that is relative to the page that the link is on.

Examples of absolute links:

• href="/": Go to the web root directory and get the default file. (The home page of

goer.org.)

• href="/HTML/: Go to the web root directory, then the HTML directory, and get the default

file. (The first page of this tutorial.)

• href="/HTML/basic/links/index.html": Go to the web root directory, then the

HTML directory, then the basic directory, then the links directory, and get the file

index.html (This page.)

Examples of relative links (relative to this page,

http://www.goer.org/HTML/basic/links/index.html):

• href="index.html": Get the index.html file that is in the current directory. (This

page.)

• href="../": Go up one directory from the current directory and get the default file. (The

first page of Chapter 2.)

• href="../../introduction/": Go up two directories from the current directory,

enter the introduction directory, and get the default file. (The first page of Chapter 1.)

As the examples demonstrate, URLs can vary in complexity while still pointing to the same

location.

For pages that are “near” the current page, relative links are often simpler. Relative links also work

better if you are working with files on your desktop, as opposed to a real websever.

Because absolute links are the same no matter where you are on the website, they’re good for

standard navigation links, header and footer links. However, absolute links don’t work as well if

you are just messing around with files on your desktop. On a webserver, an absolute link such as

/HTML/index.html starts with the webserver’s root directory. But on your local desktop, there

is no “webserver root directory”, and so your computer attempts to follow the filepath

/HTML/index.html from the root directory of your hard drive. In general, this will fail.

Linking Within Pages

We can link to web pages in external websites and internal websites. What about linking to a

particular location in a page?

All elements provide this capability through the id attribute. Once you’ve assigned an id to the

element, you can link directly to the location on the page where the element appears:

Example 2.14. Linking to an ID

1. <h2 id="fruitbat_migratory">

2. Migratory Patterns of the Fruit Bat

3. </h2>

4. ...

5. ...

6. ...

7. <p>

8. <a href="#fruitbat_migratory">link to 'Migratory Patterns of the Fruit Bat'</a>.

9. </p>

10....

The id’s value is fruitbat_migratory. Further down the page, we have a link to this ID,

specified by href="#fruitbat_migratory".

You can combine named anchors with longer URLs: for example,

http://www.goer.org/HTML/basic/links/#parts.

The pound sign in the URL makes the link point to the named anchor. If we had accidentally written

href="parts", that would have been a relative link to the directory named “parts”.

Caution

Never give two elements the same ID on the same page.

Images

Once you understand links, adding images is straightforward.

Images are a little different than the HTML headings and paragraphs that we’ve seen so far. An

image is actually a separate file that you embed in your web page using the img element. Let’s see

how this works:

Example 2.15. Example Image

1. <p>

2. Yet more evidence that I did not go to Art School:

3. </p>

4. <img src="/images/html/abc.gif" alt="a cartoon of an oscilloscope">

To try this example on your own, you not only need to copy the HTML, but you also need to

download the image “abc.gif” to your system. If you don’t know how to do this, refer to “Save

Images”. Save the file in the same directory as your test page, and try it out.

The img element has two required attributes:

• The src attribute provides a URL that points to the image file. If the URL is missing or

incorrect, the image won’t appear. The src attribute is very similar to the href attribute of

the a element. It’s too bad that they couldn’t both be called “href”, because then this would

all be easier to remember.

• The alt attribute provides “alternative text” for the image, should the image not be

displayable. This could happen if the user turns off images in their browser, or uses a

browser that doesn’t support images (such as a text-only browser or a screen reader). The

alternative text could also appear while the user is waiting for the image to download, or if

the link to the image is broken.

Some browsers display the alt text as a “tooltip” that pops up if you hover your mouse

over the image. Strictly speaking, this is incorrect behavior, because the alt attribute is for

when the image cannot be displayed. To provide “extra information” about an image, use the

optional title attribute instead.

An image file is not coded in the HTML language. Images have their own formats, such as GIF,

JPEG, or PNG. There are several ways to acquire or create digital images:

• take a photo with a digital camera

• use drawing software to create a digital image

• download an image off the web using your browser’s Save Image function

Note

It’s fine to mess around with images for learning purposes, but please don’t publish someone

else’s images on a website unless you know you have the owner’s permission.

Floating Images

Positioning elements in HTML can be tricky, and we’ll be talking about how to do this in the more

advanced sections of this tutorial. That said, let’s take a sneak preview at one of the basic concepts

of positioning: the float property.

Example 2.16. Floating Images

1. <h1>Not Your Father's Oscilloscope...</h1>

3. <img src="/images/html/oscope.gif" height="64" width="90"

4. alt="Right-floating oscilloscope"

5. style="float: right">

7. <p>

8. The <b>Model XJ-2000</b>:

9. Quality, quality, quality. That's what our bosses

10.asked for when we designed the XJ-2000, and that's

11.what we delivered. Our competitors claim to deliver

12."quality"... but do they? Sure, they prattle on about

13.about sample rates, picosecond/div sweep rates,

14.Fast Fourier Transforms, and other technical

15.mumbo-jumbo. But the fact is that the XJ-2000 is

16.light-years ahead of the competition. From the

17.scratch-resistant chrome case to the innovative

18.green phosophorescent screen, only one word should

19.spring to mind when you look at the XJ-2000: quality.

20.</p>

The float: right directive does something peculiar: it removes the image from the regular

flow of the page and “floats” it to the right. The paragraph flows around the image. If we had

specified float: left, the image would float to the left of the paragraph. (Try it!)

Just like the color and background properties, you can actually apply the float property to

nearly any element. We’ll return to this concept later.

Lists

HTML provides several ways to display lists of information:

• unordered lists: bulleted lists (like this one)

• ordered lists: numbered lists, procedures, formal outlines

• definition lists: lists of terms and definitions

Lists are different from anything we’ve covered so far, because generating a list requires at least

two elements working together.

Ordered Lists

Ordered lists are contained by an ol element. Within the <ol> and </ol> tags, each list item is

defined by an li element:

Example 2.17. Ordered Lists

1. <h3>My Dot-com Business Plan</h3>

3. <ol>

4. <li>Buy domain name</li>

5. <li>Put up website</li>

6. <li>???</li>

7. <li>Profit!</li>

8. </ol>

The default ordered list uses arabic numerals (1, 2, 3, …), but you can easily alter this behavior.

Directly within the ol element, you can only include li elements. However, within the li

elements you may place nearly any HTML content that you want: text, paragraphs, images, even

another list.

Example 2.18. Nested Ordered List

1. <h3>Schedule for Monday</h3>

3. <ol style="list-style-type: upper-roman">

4. <li>Suppress Gaul

5. <ol style="list-style-type: upper-alpha">

6. <li>Two more legions or three?</li>

7. <li>Where to put victory arch? Forum's looking crowded...</li>

8. </ol>

9. </li>

10. <li>Have Cicero killed</li>

11. <li>Lunch</li>

12. <li>Head-and-hands-on-pike viewing at the Forum (casual dress ok?)</li>

13.</ol>

Placing one list within another is a nested list. The outer list will use upper-case Roman numerals,

and the inner list will start counting independently, using upper-case letters. There are a large

number of available list-style-types for ordered lists. The most common and well-supported values

are upper-roman, lower-roman, upper-alpha, lower-alpha, and the default,

decimal. If for some reason the browser doesn’t understand the value you specify, it just falls

back to the default (decimal numbers).

You can use ol for any list of items where the order is important. This includes outlines,

procedures, TODO lists, lists of ranked items.

Unordered List

Unordered lists are similar to ordered lists, except that they do not have a particular order.

Unordered lists even recycle the li element, which makes it easy to turn an ordered list into an

unordered list and vice-versa. All you need do is turn your ols into uls:

Example 2.19. Unordered List

1. <h3>My Dot-com Business Plan</h3>

3. <ul style="list-style-type: square; color: #009900">

4. <li>Buy domain name</li>

5. <li>Put up website</li>

6. <li style="list-style-type: disc; color: #ff0000">???</li>

7. <li>Profit!</li>

8. </ul>

In the parent element ul, we’ve specified that the list should be green and that the bullets should be

squares. We overrode this behavior in the third bullet point, specifying a red, circular bullet. Notice

how the style cascades from the parent element to the child elements — each bullet takes on the

characteristics of its parent, unless we specify otherwise.

Ordered and unordered lists indent everything enclosed by the ul or ol block. You might be

tempted to use ul to indent any old HTML:

<ul>

<p>This is an indented paragraph.</p>

</ul>

Don’t do this. This is incorrect HTML, and there are better ways to achieve the same effect, as we’ll

see in “Align and Indent”. While we’re on the subject, li elements must always be enclosed by a

ul or ol element. Don’t put li elements directly in the body of the document; this is also bad

practice.

Definition Lists

A definition list provides a list of terms and definitions. Definition lists require three elements to

construct:

• dl: Denotes the definition list itself. Within the dl you may only include dt and dd

elements.

• dt: Denotes a term within the definition list. Within the dt you may only include inline

content, such as plain text and inline style elements.

• dd: Denotes a definition for a term. Within the dd you may include any block or inline

content: paragraphs, other lists, whatever you like.

A definition list consists of terms (dt) immediately followed by definitions (dd).

Example 2.20. Definition List

1. <h1>The Devil's Dictionary</h1>

3. <dl>

4. <dt>ABSURDITY, n.</dt>

5. <dd>A statement or belief manifestly inconsistent with

6. one's own opinion.</dd>

8. <dt>ACADEME, n.</dt>

9. <dd>An ancient school where morality and philosophy were

10. taught.</dd>

12. <dt>ACADEMY, n.</dt>

13. <dd>[from ACADEME] A modern school where football is

14. taught.</dd>

16. <dt>ACCIDENT, n.</dt>

17. <dd>An inevitable occurrence due to the action of immutable

18. natural laws.</dd>

19.</dl>

You may provide multiple definitions for a term, or even multiple definitions and multiple terms,

although this is less common. Some people also use definition lists to mark up screenplays and

other exchanges of dialogue: the speaker is a dt and their dialogue is a dd. If you’re writing

technical manuals, you can use definition lists to document variables, interface components, and

more. Definition lists are good for any “listed information that comes in pairs.”

Congratulations, you’ve finished the basic section! In the next section we learn about advanced font

styling, alignment, margins, and borders. Read on for more…

Chapter 3: Styling Basics

So far we’ve learned some basic HTML constructs: paragraphs, headings, and lists. That’s all very

nice, but by themselves, these elements are kind of lifeless. An h1 is just like any other h1 out

there… right?

Fortunately, no. We can customize the appearance of our h1s (and any other element) using a

language called Cascading Style Sheets (CSS). We already saw a hint of what style sheets can do

when we were mucking around with the foreground color and background color. But CSS can do

much more than this.

As an example of what CSS can do, take a walk through the CSS Zen Garden. Each page in the

CSS Zen Garden has exactly the same text and markup. The only difference is the CSS, but each

page appears radically different.

First, we’re going to learn a new method for applying styles that is much more efficient than what

we’ve been doing in the previous chapters. At first, we’ll only be changing the color, because color

is simple and gets the point across. But by the end of this chapter, you’ll have expanded your style

vocabulary dramatically.

When you’re done with this section, you should be able to:

• Create a style sheet for your web page or for your entire web site.

• Create named, reusable styles using classes and IDs.

• Apply sophisticated font changes to any HTML element.

• Change the padding, margins, and borders.

• Align and indent your text.

Section Summaries

The Styling Basics chapter contains these sections:

1. The style Attribute — Describes the basic problem that style sheets are designed to solve.

2. Style Sheets — Describes style sheets, which provide a convenient method for collecting

styling rules in one place and applying them to an entire website. We’ll cover CSS rule

syntax and the basics of cascading.

3. Classes and IDs — Explains how to create more specialized CSS rules by using CSS classes

and IDs.

4. Div and Span — Describes the “generic” HTML elements div and span, which provide a

way to apply styles to any given swath of HTML.

5. Font Control —Provides more sophisticated methods for controlling a document’s font. We

examine how to change the font family, font size, and font styling. We’ll also take a look at a

stylesheet that is a bit more complex than the ones we’ve seen in earlier sections.

6. Borders — Explains how to set border properties such as color and thickness, how to set

different borders on all four sides, and how to use border shorthand notation.

7. Margins and Padding — Describes padding (extra space inside an element’s border) and

margins (extra space outside an element’s border).

8. Align and Indent — Describes text indentation and alignment. We’ll learn how to create

hanging indents and align text horizontally. (Aligning blocks will come later, in the sections

on positioning.)

The style Attribute

So far we’ve dealt with two major components to our web pages: the elements, which define the

basic structure of the page, and the styling, which further refines how the page should look. We saw

the effects of styling in “Colors”:

Example 3.1. Red Paragraph (Redux)

1. <p>

2. The grandmother lived out in the wood, half a league from the village,

3. and just as Little Red-Cap entered the wood, a wolf met her. Red-Cap

4. did not know what a wicked creature he was, and was not at all afraid

5. of him.

6. </p>

7. <p style="color: red">

8. 'Good day, Little Red-Cap,' said he.

9. </p>

10.<p>

11. 'Thank you kindly, wolf.'

12.</p>

Now, it’s nice that we can make a single paragraph red, but what if we wanted all paragraphs to be

red? Or what if we wanted to do something more than just changing the paragraph’s color?

In the early 1990s, the only way to do control the color, size, and font of your text was the font

element. So people wrote a lot of HTML that looked like this:

Example 3.2. The font Element

1. <B><I><FONT Size="+2">

2. <FONT FACE="Palatino, Arial, Helvetica">

3. <FONT color="#ff0000">

4. Kneel Before the Power of the Font Element!

5. </FONT>

6. </font></Font></i></B>

8. <p><FONT Size="-1">

9. <FONT FACE="Arial, Helvetica, sans-serif">

10.<FONT color="#123456">

11.Ow! The bad HTML code! It burns us, burns us, precious!

12.</font></font></FoNt></p>

This was a tremendous pain for many reasons. You had to keep typing this kind of markup all over

the page, and if your boss told you later on to change the font size, you had to redo all this code

again.

The style attribute is an improvement over the font element, but it still suffers from the same

basic problem: it isn’t reusable. You don’t want to have to add a style element to every element

on the page. Fortunately, there is a much better way to do all of this. These days, you should never

use the font element, and the style attribute only sparingly if at all. In the next section, we’ll

look at a much better way to do this.

Style Sheets

Every time we’ve specified style="(something)", we’ve actually created a CSS rule.

Although CSS (Cascading Style Sheets) is a different language from HTML proper, it is an

indispensable tool for controlling the appearance of your website. Think of each webpage as having

three components:

• Structure: The markup is like the page’s skeleton. It provides the basic structure for the

page: headings, sections, paragraphs, lists, and more. Without structure, your web page

would just be an undifferentiated blob of text.

• Content: The content (text, images, and even audio or video), is like the page’s flesh. This is

the “meat” of the page. Without content, there’s nothing to read, and no reason to visit the

page in the first place.

• Presentation: The CSS is the page’s skin, hair, clothes, and makeup. Without presentation,

your page might be readable, but it won’t be very attractive.

So far we’ve only been working with individual styles applied to individual elements. Although this

works, it is not the most efficient way to apply our styles. A far better technique is to collect all our

CSS rules in one place, a style sheet, and then apply the style sheet to every single element on the

page… or for that matter, every single element throughout the entire website. Let’s see how this

works.

Embedded Style Sheets

An embedded style sheet affects every element on the page. In order to create an embedded style

sheet, we need to go to the head of the document. (Remember the hea d elemen t? Finally, here’s

something else that goes there besides the title element.)

Here’s an example of an embedded style sheet (please forgive the garish green-on-yellow):

Example 3.3. All Green Paragraphs

1. <html>

2. <head>

3. <title>When Irish Eyes Are Smiling</title>

4. <style type="text/css">

5. p {color: #008000; background: #ffff00}

6. </style>

7. </head>

8. <body>

9. <h1>When <em>Irish Eyes</em> Are Smiling</h1>

10. <p>

11. Here's how the chorus goes:

12. </p>

13. <p>

14. When Irish eyes are smiling,<br>

15. <em>Sure, 'tis like the morn in Spring.</em><br>

16. In the lilt of Irish laughter<br>

17. <em>You can hear the angels sing.</em><br>

18. When Irish hearts are happy,<br>

19. <em>All the world seems bright and gay.</em><br>

20. And when Irish eyes are smiling,<br>

21. <em>Sure, they steal your heart away.</em>

22. </p>

23.</body>

24.</html>

The syntax is a little different from what we are used to, but the core idea (the CSS rule) should

look familiar. Let’s examine the style sheet’s components:

• <style type="text/css">: The style element indicates the beginning of the style

sheet. It must go inside the head. The type attribute specifies that you are using a CSS

style sheet, as opposed to using some other, yet-to-be-invented style sheet language. It’s a bit

silly, but the HTML specification requires it, so go ahead and add it.

• p: The CSS selector. This says, “do something to all p elements.”

• {color: #008000; background: #ffff00}: The CSS declarations. We’ve seen

these before in the style element, although without the curly braces. Together with the

selector p, the declarations constitute a CSS rule: “make all paragraphs green text with a

bright yellow background.” As mentioned in “Background Color”, you must separate

multiple declarations with a semicolon.

Note

You will sometimes see people wrap their embedded CSS rules in an HTML comment, like so:

rules from extremely ancient browsers that cannot process CSS at all, namely Mosaic and Netscape

Navigator 1.0. Fortunately, these browsers are long-dead, and there is no need to do this anymore.

Now, we could have achieved the same effect by adding these declarations to the style attribute

of each paragraph. The key difference is that the style sheet affects all paragraphs. The selector

enables us to specify the declarations once, and the browser then applies them to all elements that

match the selector.

Multiple CSS Rules and Selectors

You may specify as many rules as you like in a style sheet. Consider the following:

Example 3.4. Green Paragraphs, Red Body

1. <html>

2. <head>

3. <title>When Irish Eyes Are Smiling</title>

4. <style>

5. body {background: #ff0000}

6. p {color: #008000; background: #ffff00}

7. </style>

8. </head>

9. <body>

10. <h1>When <em>Irish Eyes</em> Are Smiling</h1>

11. <p>

12. Here's how the chorus goes:

13. </p>

14. <p>

15. When Irish eyes are smiling,<br>

16. <em>Sure, 'tis like the morn in Spring.</em><br>

17. In the lilt of Irish laughter<br>

18. <em>You can hear the angels sing.</em><br>

19. When Irish hearts are happy,<br>

20. <em>All the world seems bright and gay.</em><br>

21. And when Irish eyes are smiling,<br>

22. <em>Sure, they steal your heart away.</em>

23. </p>

24.</body>

25.</html>

Here we’ve specified that the body of the page should have a red background, while all paragraphs

should have a yellow background with green text. This color combination is so awful that I am

loathe to discuss this example further. Let’s move on.

The key feature of CSS rules is that they are reusable. We’ve already seen that we can use them to

apply a set of CSS declarations to, say, all p elements. But it gets better — we can also give a rule

with multiple selectors. Just separate the selectors with commas:

element1, element2 { declarations }

This applies the declarations to both element1 and element2. For example:

Example 3.5. Green Paragraphs and Headings

1. <html>

2. <head>

3. <title>When Irish Eyes Are Smiling</title>

4. <style>

5. p, h1 {color: #008000; background: #ffff00}

6. </style>

7. </head>

8. <body>

9. <h1>When <em>Irish Eyes</em> Are Smiling</h1>

10. <p>

11. Here's how the chorus goes:

12. </p>

13. <p>

14. When Irish eyes are smiling,<br>

15. <em>Sure, 'tis like the morn in Spring.</em><br>

16. In the lilt of Irish laughter<br>

17. <em>You can hear the angels sing.</em><br>

18. When Irish hearts are happy,<br>

19. <em>All the world seems bright and gay.</em><br>

20. And when Irish eyes are smiling,<br>

21. <em>Sure, they steal your heart away.</em>

22. </p>

23.</body>

24.</html>

Now the green text and yellow background applies to paragraphs and level 1 headings.

So far, we’ve only seen simple selectors that just select a single element. However, you can design

selectors to be more “choosy” than this. One of the most useful variations is:

element1 element2 { declarations }

This looks similar to Example 3.5, “Green Paragraphs and Headings”, but notice there is no comma

between the elements. That one little comma makes a big difference. This rule applies its

declarations only to element2s that are contained within element1s. Let’s see how this works:

Example 3.6. Green paragraphs, Blue ems

1. <html>

2. <head>

3. <title>When Irish Eyes Are Smiling</title>

4. <style>

5. p {color: #008000; background: #ffff00}

6. h1 em { color: #0000ff }

7. </style>

8. </head>

9. <body>

10. <h1>When <em>Irish Eyes</em> Are Smiling</h1>

11. <p>

12. Here's how the chorus goes:

13. </p>

14. <p>

15. When Irish eyes are smiling,<br>

16. <em>Sure, 'tis like the morn in Spring.</em><br>

17. In the lilt of Irish laughter<br>

18. <em>You can hear the angels sing.</em><br>

19. When Irish hearts are happy,<br>

20. <em>All the world seems bright and gay.</em><br>

21. And when Irish eyes are smiling,<br>

22. <em>Sure, they steal your heart away.</em>

23. </p>

24.</body>

25.</html>

This specifies em elements to be blue, if and only if they are contained within an h1. The em in the

h1 at the top of the page turns blue, but the ems in the paragraphs below are unaffected.

We’ll see a couple more examples of useful selectors in “Classes and IDs”. For a complete list of

selector syntax, refer to the official CSS specification.

Style Sheet Cascading

What happens when CSS rules conflict? Here’s where the “Cascading” part of Cascading Style

Sheets comes in. The official rules are complicated, but they basically boil down to “whichever CSS

rule is ‘nearer’ or ‘more specific’ wins.”

Returning to our song lyric example, let’s say we didn’t want the first paragraph to be in green text:

Example 3.7. One Green Paragraph

1. <html>

2. <head>

3. <title>When Irish Eyes Are Smiling</title>

4. <style type="text/css">

5. p {color: #008000; background: #ffff00}

6. </style>

7. </head>

8. <body>

9. <h1>When <em>Irish Eyes</em> Are Smiling</h1>

10. <p style="color: #000000">

11. Here's how the chorus goes:

12. </p>

13. <p>

14. When Irish eyes are smiling,<br>

15. <em>Sure, 'tis like the morn in Spring.</em><br>

16. In the lilt of Irish laughter<br>

17. <em>You can hear the angels sing.</em><br>

18. When Irish hearts are happy,<br>

19. <em>All the world seems bright and gay.</em><br>

20. And when Irish eyes are smiling,<br>

21. <em>Sure, they steal your heart away.</em>

22. </p>

23.</body>

24.</html>

The first paragraph has black text. Our style attribute is more specific than the general page-level

CSS, and so the black-text rule overrides the green-text rule. However, the paragraph still has a

yellow background. The yellow-background rule cascades down to this paragraph, because we

didn’t specify anything about it.

Another important cascading rule is that parent elements apply their style to their children (enclosed

elements). Rules applied to the body element cascade down to enclosed p elements, rules applied

to p elements cascade down to enclosed em elements, and so on. In fact, we saw this form of

cascading in Example 3.4, “Green Paragraphs, Red Body”. The background of the page is red, and

any child elements also have a red background… except for paragraphs, which specifically override

this rule.

Reusable Style Sheets

What’s better than applying styles to an entire page? Applying it to an entire website.

CSS enables you to place your style sheet in a separate file. The stylesheet then becomes a central

repository of CSS rules that you can apply to any page in a site. There are two ways to “call” a

global style sheet into a given page:

Example 3.8. Global Style Sheets: The “link” Method

1. <html>

2. <head>

3. <title>When Irish Eyes Are Smiling</title>

4. <link rel="stylesheet" href="/css/style1.css" type="text/css">

5. <link rel="stylesheet" href="/css/style2.css" type="text/css">

6. <style>

7. p {color: #008000; background: #ffff00}

8. </style>

9. </head>

Example 3.9. Global Style Sheets: The “@import” Method

1. <html>

2. <head>

3. <title>When Irish Eyes Are Smiling</title>

4. <style>

5. @import url("/css/styles3.css");

6. @import url("/morecss/styles4.css");

7. body {background: #ff0000}

8. p {color: #008000; background: #ffff00}

9. </style>

10.</head>

The two methods have bizarrely different syntax, but functionally they are similar. They both allow

you to specify multiple stylesheet files, and you may use them both in conjunction with an

embedded style sheet.

A linked style sheet also affects the rules for cascading:

• A rule in a linked style sheet has low priority.

• A rule in an embedded style sheet has medium priority.

• A declaration in a style attribute has high priority.

This means you can specify a style in a linked style sheet, override that style for a particular page,

and then override it again for a particular element. For example, if we have the page:

1. <html>

2. <head>

3. <title>What is your favorite color?</title>

4. <link rel="stylesheet" href="/css/style.css" type="text/css">

5. <style>

6. em {color: yellow}

7. </style>

8. </head>

9. <body>

10. My favorite color is <em style="color: blue">blue</em>.

11.</body>

and the linked stylesheet “style.css” contains:

em {color: blue}

then the browser uses the following logic to color the em:

1. The linked style sheet specifies the em to be blue.

2. The embedded style sheet specifies the em to be yellow, overriding the linked style sheet.

3. The style attribute specifies the em to be blue again, overriding the embedded style sheet.

So the resulting color is “blue”. Whew.

Classes and IDs

The last section demonstrated how a style sheet can apply a style to all elements in a web page. If

we want all our paragraphs to be red, we just need to specify p {color: red} in the style sheet.

Easy, we’re done.

But what if we want only some paragraphs to be red? We could override our “red-text” rule by

making copious use of the style attribute: <p style="color: black">. However, as “The

styl e Attribute ” points out, this is not a good solution in the long term.

Fortunately, there is a way to “name” a style and re-use it over and over. This method is called a

style sheet class.

Style Sheet Classes

In Example 3.10, “Two CSS Classes”, we have an exchange of dialogue between two characters.

We’ll differentiate each character’s lines by applying a unique style. It would be tedious and

counterproductive to write out the full style in each p element, so instead we’ll define each style

once in the style sheet and use a class to call it multiple times.

Example 3.10. Two CSS Classes

1. <html>

2. <head>

3. <title>An Ideal Husband</title>

4. <style type="text/css">

5. p {color: #000000}

6. p.goring {color: #ff0000}

7. p.phipps {color: #008000}

8. </style>

9. </head>

10.<body>

11. <p class="goring">

12. LORD GORING. [Taking out old buttonhole.] You see, Phipps, Fashion

13. is what one wears oneself. What is unfashionable is what other

14. people wear.

15. </p>

16. <p class="phipps">

17. PHIPPS. Yes, my lord.

18. </p>

19. <p class="goring">

20. LORD GORING. Just as vulgarity is simply the conduct of other

21. people.

22. </p>

23. <p class="phipps">

24. PHIPPS. Yes, my lord.

25. </p>

26. <p class="goring">

27. LORD GORING. [Putting in a new buttonhole.] And falsehoods the

28. truths of other people.

29. <p class="phipps">

30. PHIPPS. Yes, my lord.

31. </p>

32. <p class="goring">

33. LORD GORING. Other people are quite dreadful. The only possible

34. society is oneself.

35. </p>

36. <p class="phipps">

37. PHIPPS. Yes, my lord.

38. </p>

39. <p class="goring">

40. LORD GORING. To love oneself is the beginning of a lifelong romance,

41. Phipps.

42. </p>

43. <p class="phipps">

44. PHIPPS. Yes, my lord.

45. </p>

46.</body>

47.</html>

For each character, we’ve defined a class, goring and phipps. Note that we’ve introduced a

brand-new CSS selector: instead of

element { declarations }

We have

element.class { declarations }

Once we define the selectors p.goring and p.phipps, we can apply them to any paragraph

through the class attribute. You may add the class attribute to any element that can take the

style element (in other words, most of them). The class attribute is usually much better to use

than the style attribute, because it’s much easier to change what a class means later on.

In Example 3.10, “Two CSS Classes”, the classes only work with the p element. Applying them to

some other element, as in, <em class="goring">, would fail. To make the selector “generic”

so that it works with any element, just leave off the element name:

.goring {color: #ff0000}

Unique IDs

Another method for assigning styles is to use an ID. An ID is a unique identifier for a element on a

page. IDs are different from classes in a couple of key ways:

• IDs are unique. You may only use a particular ID once on a page.

• You can use IDs to create a link to a specific location within a page, as discussed in “Linking

Within Pages”.

To apply a style to an ID, the syntax should look familiar. Instead of using a period, use a hash mark

(#):

p#goring {color: #ff0000}

That’s it. In order to apply the style, you would just write <p id="goring">, as opposed to <p

class="goring">.

The only problem here is that you may only apply id="goring" once on the entire web page. In

other words, we are presuming that Lord Goring is speaking only once. Given what we know of

Lord Goring, this is probably a bad assumption.

If you use IDs in your style sheets, make sure that they are for unique elements. IDs are ideal for

navigation bars, headers, footers, and other elements that appear only once on the page.

Div and Span

As we’ve seen in previous sections, using CSS is straightforward. Provide a selector (”select all p

elements”), provide a rule (”make their text red”), and we’re done. Both the selectors and the rules

can be much more complicated, but this is the core of it.

Let’s take a look at another component of our style sheet toolbox: the “generic” elements, div and

span. These elements are designed to help you mark off arbitrary chunks of HTML for styling.

The span Element

The span element is the generic inline element. Let’s see this element in action:

Example 3.11. Empty span

1. <p>

2. Towards thee I roll, thou all-destroying but

3. unconquering whale; <span>to the

4. last I grapple with thee; from hell's heart I stab

5. at thee; for hate's sake I spit my last breath at

6. thee.</span> Sink all coffins and all

7. hearses to one common pool! and since neither can

8. be mine, let me then tow to pieces, while still

9. chasing thee, though tied to thee, thou damned

10. whale! Thus, I give up the spear!

11.</p>

If you view the results, it looks like… the span didn’t do anything. And that’s the point: by default,

the span element isn’t supposed to do anything. It serves as a placeholder or marking point for

beginning and ending a style.

Let’s make a minor change. We’ll create a class for our span element and apply that class to our

selection from Moby-Dick.

Example 3.12. Red span

1. <html>

2. <head>

3. <title>Moby-Dick</title>

4. <style type="text/css">

5. span.khan {color: #ff0000}

6. </style>

7. </head>

8. <body>

9. <p>

10. Towards thee I roll, thou all-destroying but

11. unconquering whale;

12. <span class="khan">to the last I

13. grapple with thee; from hell's heart I stab at

14. thee; for hate's sake I spit my last breath at thee.

15. </span> Sink all coffins and all

16. hearses to one common pool! and since neither

17. can be mine, let me then tow to pieces, while

18. still chasing thee, though tied to thee, thou

19. damned whale! Thus, I give up the spear!

20. </p>

21.</body>

22.</html>

Now we have an inline element, <span class="khan">, that can make any inline selection of

HTML red.

Tip

Before using the generic span element, try using an em, strong, code, or other logical style. If

possible, it's better to start with an element that has some intrinsic meaning.

The div Element

The div element is the generic block element. You can use div to apply styles to large sections of

HTML, such as multiple paragraphs. Like all block elements, the div element defines a “box” of

HTML.

Example 3.13. Red div

1. <html>

2. <head>

3. <title>Product Brochure</title>

4. <style type="text/css">

5. div.important {color: #ff0000}

6. </style>

7. </head>

8. <body>

9. <p>

10. Congratulations on the purchase of your sword!

11. Using a sword is fun and easy. Just be

12. sure to follow these important safety tips.

13. </p>

14. <div class="important">

15. <p>

16. <em>Never</em> hold your sword by the pointy end.

17. </p>

18. <p>

19. <em>Always</em> be sure to stick the pointy end

20. into the other guy before he does the same to you.

21. </p>

22. </div>

23. <p>

24. And remember, if you or your surviving kinsfolk are

25. not fully satisfied, we have a money-back guarantee!

26. </body>

27.</html>

The div element applies the style to the second and third paragraphs. Note that even though the

div element is a “block” element, it does not create extra line breaks between paragraphs 1 and 2

or paragraphs 3 and 4. However, if we had tried to insert the div inside one of the paragraphs, we

would have created a new text block. (Try it.)

Font Control

In our earlier section about font styles, we looked at the effects of the em and strong elements on

text. While these elements enable you to apply some simple font changes (italic, bold), it would be

nice to have more options.

Now that we’ve covered the basics of style sheets, it’s time to examine more sophisticated methods

of font control. CSS font control is divided into three main components:

• font-famil y: What is the name of the font?

• font-siz e: How big is the font?

• font-weigh t: Is the font bold?

• font-styl e: Is the font italic?

• text-decoratio n: Is the font underlined, struck through, …?

We’ll tackle each of these properties one-at-a-time.

The font-family Property

The font-family property selects the name of the font you wish to use. This component is

pretty straightforward:

body { font-family: times new roman }

This CSS rule specifies that all text in the body should be in Times New Roman. Times New

Roman isn’t necessarily a great font to use on the web, but it should be familiar to anyone who uses

a word processor.

Specifying Multiple Fonts

One of the unavoidable issues of web design is that you can’t count on any particular browser

rendering your page exactly the way you want it to be. Fonts are no exception. You might want your

text to use some fancy font, but what if your reader’s browser doesn’t have that font available?

To resolve this issue, font-family enables you to specify multiple fonts. Here’s an example:

body { font-family: georgia, palatino, times new roman, serif }

The list of fonts proceeds in descending order of importance. The browser first tries to display the

font Georgia. If Georgia is not available, it will try Palatino; failing that, Times New Roman; and if

all hope is lost, a generic serif font.

There are some fonts that are usually available on on most people’s browsers. These include Times

New Roman, Georgia, Palatino, Lucida, Impact, Trebuchet MS, Verdana, Comic Sans MS, Arial,

Courier New, and Courier. However, even this impoverished selection is not always available.

Worse, some of these “canonical” fonts are ill-suited for reading on a computer screen. Many

websites declare their fonts to be “Arial, Helvetica, sans-serif”. But as accessibility expert Joe Clark

says in his book Building Accessible Websites:

“Don’t use Helvetica. Typographic neophytes think Helvetica is “legible.” Try running a

few tests with confusable characters like Il1i!A!|, 0OQ, aeso, S568, or quotation marks.

Related grotesk typefaces like Univers suffer similarly. (One more time: Don’t use

Arial. It’s a bastardized variant of Helvetica, it’s ugly, it bespeaks unsophistication, and

it sticks you with all the same confusable characters as other grotesks.)”

Generic Fonts

If you specify the keyword “sans-serif” at the end of a list of fonts, this directs the browser to use

some form of sans-serif. Specifying a generic font keyword is always a last resort, to be used if

none of the fonts you name in your list are available.

There are five varieties of generic fonts, but only the first three are all that important.

• sans-serif: lacks decoration or flaring at the end of each stroke.

Examples include Verdana, Arial, and Geneva.

• serif: has decoration or flaring at the end of some of its strokes.

Examples include Times New Roman, Garamond, and Georgia. Printed materials often use

serif fonts, because the serifs make the characters easier to distinguish and thus, easier to

read. However, on the web, the reverse can be true. On paper, the little complicated serifs are

sharp and easy to distinguish, but on a fuzzy computer screen, it’s often easier on the eyes to

use sans-serif.

• monospace: uses the same width for each character, often used to represent computer code

or terminal text.

Examples include Courier, Courier New, Monaco, and Andale Mono. The most wellsupported

monospace fonts are Courier and Courier New.

• cursive: designed to mimic handwriting.

Examples include Brush Script MT, Aristocrat LET, and Comic Sans MS. The most wellsupported

cursive font is Comic Sans MS, a cartoony font designed to resemble a child’s

writing. Most other cursive fonts are not well-supported.

• fantasy: highly decorative.

Examples include Impact and Copperplate. Most fantasy fonts are not well-supported.

The font-size Property

The font-size property enables you to specify your font size in a number of absolute and

relative ways:

• points (”font-size: 12pt“): Measured in “points” (units of 1/72 of an inch).

• pixels (”font-size: 14px“): Measured in screen pixels.

• percentages (”font-size: 150%“): Measured relative to the default font or the parent

element’s font. A font size of “75%” would shrink the font by a factor of 3/4.

• em-widths (”1.2em“): (Not to be confused with the em element.) Measured relative to the

default font or the parent element’s font. The value “1.0em” is the same as multiplying by

one.

• absolute keywords (”x-large“): Specifies one of seven sizes: xx-small, x-small,

small, medium, large, x-large, and xx-large. The exact interpretation of what

constitutes “medium” or “x-large” varies from browser to browser.

• relative keywords (”larger“): Bumps the font up one size or down one size from its

default or inherited size. The options are larger and smaller.

Note

Always keep in mind that people can and will override your font size settings. All browsers provide

a text-zoom function, and people with weak eyesight (think, “people over thirty”) are quick to make

use of it.

Modern browsers handle these ways of specifying the font size reasonably well, although there are

some inconsistencies. But in the older browsers, font size handling is spotty at best. For example:

• Old versions of Internet Explorer used a default font size of small instead of medium.

• For the size keywords, Netscape 4 used a huge scaling factor between the different size

keywords. Using xx-small or x-small often made the text unreadable, x-large and

xx-large were a sight to behold.

• The only way to get consistent font sizes across all the old browsers was to use pixels (px).

However, due to a bug in old versions of Internet Explorer, using pixels disabled Internet

Explorer’s ability to resize the text! That’s why you’ll see some websites with “text resize

buttons”, even though these buttons shouldn’t be necessary.

Although these issues are generally improving over time, it can be quite a struggle to get your font

sizes looking consistent and resizing properly even in the newer browsers.

Tip

The Yahoo! User Interface team provides a free fonts.css file that solves many of these

consistency and resizing problems for you.

Additional font-styling

Beyond specifying the font name and its size, you can further alter the font’s appearance. We’ve

already covered how to change the text color in “Colors”. Further alterations include making the

text bold (darker), italic (slanted), and much more.

font-weight (boldness)

The font-weight component specifies how thick the font’s strokes should be. The important

values to know are normal and bold.

You may also specify, bolder, lighter, or a number from 100 to 900. (400 corresponds to

normal and 700 to bold.) However, these variations don’t do much even in the newer browsers.

In general, everything 500 and above is just bold. There isn’t any such thing as really bold, at least

not yet.

The normal option removes any boldness that has already been applied. For example, most

browsers display strong as bold text. If you wanted to take this effect away, you could write

strong {font-weight: normal}; in your style sheet.

font-style (italic)

The font-style component specifies whether or not the font is slanted (italic). The most

commonly-used value is italic.

As with font-weight, there is also a value of normal that enable you to un-italicize something

that would ordinarily be italicized. For a demonstration, refer to “An Example: Styling the em

Element”.

text-decoration (underlines and more)

Sadly, text-decoration doesn’t have a sensible, consistent name (such as “font-decoration”).

But its purpose is similar to the components we’ve already discussed. text-decoration

provides five options:

• none: cancels all text-decoration.

• underline: creates underlined text.

• overline: creates overlined text.

• line-through: creates line-through (”strike-through”) text.

• blink: creates blinking text.

Caution

Avoid using blink. Most people hate blinking text, and many browsers don’t implement this

option anyway.

Take care using underline. Most people associated underlined text with hyperlinks. Avoid

underlining your (non-link) text unless absolutely necessary.

An Example: Styling the em Element

While most browsers display em as simply italic, there’s no intrinsic reason why this should be so

— it just happens to be the convention. Let’s say that instead we want our em elements to be bold,

red, and larger than our default font size. How would we do this?

Example 3.14. Styled Elements

1. <html>

2. <head>

3. <title>Oh Better Far to Live and Die</title>

4. <style type="text/css">

5. p {

6. font-family: courier, monospace;

7. font-size: 12pt;

8. }

9. em {

10. font-style: normal;

11. font-weight: bold;

12. font-size: 14pt;

13. color: #ff0000;

14. }

15. </style>

16.</head>

17.<body>

18. <p>

19. KING:<br>

20. For... I <em>am</em> a Pirate <em>King!</em><br>

21. And it is, it is a glorious thing<br>

22. To be a Pirate King!<br>

23. For I am a Pirate <em>King!</em>

24. </p>

25. <p>

26. ALL:<br>

27. You are! <br>

28. <em>Hurrah</em> for the Pirate King!

29. </p>

30. <p>

31. KING:<br>

32. And it is, it is a glorious thing <br>

33. To be a Pirate King.

34. </p>

35.</body>

36.</html>

We’ve defined a default style for our paragraphs, and the em element style overrides it. Notice that

we don’t have to specify the font-style for our paragraphs: the default value is normal (non-italic),

and presumably we’re happy with that.

The font styling that we apply to the p element cascades down to the em element. Let’s take a look

at what’s happening step-by-step.

1. font-family:

• p element: set to courier, monospace. If the browser can display Courier it

will; otherwise it will serve up a generic monospace font.

• em element: inherits its font-family from the parent element, p.

2. font-size:

• p element: set to 12pt.

• em element: set to 14pt, overriding its parent.

3. font-weight:

• p element: not set; takes on the default value of normal.

• em element: set to bold, overriding the default em value of normal.

4. font-style:

• p element: not set; takes on the default value of normal.

• em element: set to normal, overriding the default em value of italic.

5. color:

• p element: not set; takes on the default value of #000000.

• em element: set to #ff0000, overriding the default em value of #000000.

Font Shorthand Notation

Typing font-family, font-size, and font-style over and over again can get

cumbersome. Fortunately, there is a shorthand for all of these properties with a simple name, font.

You need merely place the desired values in the proper order. This shorthand only encompasses the

properties that begin with “font-”, so if you want to do something else such as underlining text, you

still need to use the appropriate property, text-decoration.

Here is the order of the properties:

1. font-style or font-weight or both

2. font-size

3. font-family

You may leave out any of these properties except for the font-family, as long as everything is

in the proper order. Let’s take a look at an example of some paragraph classes.

Example 3.15. The font Property

1. p {

2. font: verdana, sans-serif;

3. }

4. p.styled {

5. font: 12pt verdana, sans-serif;

6. }

7. p.reallystyled {

8. font: bold italic 9pt verdana, sans-serif;

9. text-decoration: underline;

10. color: #008000;

11.}

The default paragraph is just Verdana, in whatever font size the page default is currently in. The

standard class, styled, is 12pt Verdana. The second class, reallystyled, is 9pt bold italic

underlined green Verdana.

The font property makes things a bit more elegant, but keep in mind that some browsers will

display styles that are not properly ordered, while others are more strict about following the rules.

To be safe, always verify that that your font declarations are in the proper order before

proceeding.

Box Model: Borders

The CSS box model is a collection of CSS properties that apply to all visual HTML elements. As

Figure 3.1, “The Box Model” indicates, any HTML element, such as:

<p>The quick brown fox jumped over the lazy dog.</p>

is nested inside three boxes:

The margin encloses the border, which encloses the padding, which encloses the content. You can

use CSS to style all three of these independently.

Border Widths, Styles, and Colors

The easiest component of the box model to understand is the border, because it can be so visually

striking. Most elements do not have borders by default, but they’re easy enough to add with these

CSS properties:

• border-width: A length, such as 3px or 0.2em. Most web designers specify their

borders in pixels.

• border-color: A color, such as green or #ff0000. The default color is usually black.

• border-style: A keyword that indicates how to draw the border’s lines. The basic style

is solid, but there are fancier options available, such as dashed, dotted, double,

groove, inset, outset, and ridge. There is also a none option that suppresses

borders. If a browsers does not support a particular “fancy” border style, it usually replaces

that style with solid.

You can apply borders to any visible element you like: divs, lists, and so on. In the following

example, we create generic classes, and apply them to p elements.

Example 3.16. Four Border Examples

1. <html>

2. <head>

3. <style>

4. .thickline {

5. border-width: 10px;

6. border-style: solid;

7. }

9. .thinblueline {

10. border-width: 1px;

11. border-color: #0000ff;

12. border-style: solid;

13. }

14.

15. .greenridge {

16. border-width: 5px;

17. border-color: green;

18. border-style: ridge;

19. }

20.

21. .empurpledash {

22. border-width: 0.5em;

23. border-color: #800080;

24. border-style: dashed;

25. }

26. </style>

27.</head>

28.<body>

29. <p class="thickline">

30. "1st, The man-mountain shall not depart from our

31. dominions, without our license under our great seal.

32. </p>

33. <p class="thinblueline">

34. 2d, He shall not presume to come into our metropolis,

35. without our express order; at which time, the inhabitants

36. shall have two hours warning to keep within doors.

37. </p>

38. <p class="greenridge">

39. 3d, The said man-mountain shall confine his walks

40. to our principal high roads, and not offer to walk, or

41. lie down, in a meadow or field of corn.

42. </p>

43. <p class="empurpledash">

44. 4th, As he walks the said roads, he shall take the

45. utmost care not to trample upon the bodies of any

46. of our loving subjects, their horses, or carriages, nor

47. take any of our subjects into his hands without their

48. own consent.

49. </p>

50.</body>

51.</html>

The first three borders are specifed in pixels. The last is in em, which means that if we change the

p’s font size, the border thickness should scale with it.

Four Different Sides

To apply a different border to each side, you must break down border-width, bordercolor,

and border-style into their constituent components:

• border-width becomes: border-top-width, border-bottom-width,

border-right-width, and border-left-width.

• border-color becomes: border-top-color, border-bottom-color,

border-right-color, and border-left-color.

• border-style becomes: border-top-style, border-bottom-style,

border-right-style, and border-left-style.

Here’s an admittedly silly example with four different borders:

Example 3.17. Four Different Sides

1. <html>

2. <head>

3. <style>

4. p.fourborders {

5. border-top-width: 5px;

6. border-top-color: #ff0000;

7. border-top-style: dashed;

9. border-bottom-width: 10px;

10. border-bottom-color: #336600;

11. border-bottom-style: groove;

12.

13. border-right-width: 20px;

14. border-right-color: #000080;

15. border-right-style: solid;

16.

17. border-left-width: 10px;

18. border-left-color: #CC9900;

19. border-left-style: solid;

20. }

21.</style>

22.</head>

23.

24.<body>

25. <p class="fourborders">

26. "But I thought all witches were wicked," said the girl, who

27. was half frightened at facing a real witch. "Oh, no, that is a

28. great mistake. There were only four witches in all the Land of

29. Oz, and two of them, those who live in the North and the South,

30. are good witches. I know this is true, for I am one of them

31. myself, and cannot be mistaken. Those who dwelt in the East and

32. the West were, indeed, wicked witches; but now that you have

33. killed one of them, there is but one Wicked Witch in all the Land

34. of Oz--the one who lives in the West."

35. </p>

36.</body>

37.</html>

Border Shorthand Notation

As with the font- properties, there is a shorthand notation named border. Unlike font, you

may specify the border properties in any order.

Below is a version of Example 3.18, “Four Border Examples”, reformulated to use the shorter

notation. The properties appear in essentially random order, but the results are the same as before.

Example 3.18. Four More Border Examples

1. <html>

2. <head>

3. <style>

4. .thickline {

5. border: 10px solid;

6. }

8. .thinblueline {

9. border: 1px #0000ff solid;

10. }

11.

12. .greenridge {

13. border: ridge 5px green;

14. }

15.

16. .empurpledash {

17. border: #800080 0.5em dashed;

18. }

19. </style>

20.</head>

21.<body>

22. <p class="thickline">

23. "1st, The man-mountain shall not depart from our

24. dominions, without our license under our great seal.

25. </p>

26. <p class="thinblueline">

27. 2d, He shall not presume to come into our metropolis,

28. without our express order; at which time, the inhabitants

29. shall have two hours warning to keep within doors.

30. </p>

31. <p class="greenridge">

32. 3d, The said man-mountain shall confine his walks

33. to our principal high roads, and not offer to walk, or

34. lie down, in a meadow or field of corn.

35. </p>

36. <p class="empurpledash">

37. 4th, As he walks the said roads, he shall take the

38. utmost care not to trample upon the bodies of any

39. of our loving subjects, their horses, or carriages, nor

40. take any of our subjects into his hands without their

41. own consent.

42. </p>

43.</body>

44.<html>

This shorthand is convenient, but keep in mind that the border property can only set the same

border on all four sides. Fortunately, there are yet four more shorthand properties that apply the

border’s width, color, and style to just one side at a time: border-top, border-right,

border-bottom, and border-left. For example, if you wanted to apply the green ridge

border to just the left side of an element, the code:

1. .greenridge {

2. border-left: ridge 5px green;

3. }

would do the trick.

Box Model: Margins and Padding

Now that we’ve covered borders, let’s return to our examination of the box model.

Padding

In “Borders”, you might have noticed that in all border examples, the text and the borders were

rather close together.

An element’s padding is the element’s “extra space inside the border”. There are four padding

properties: padding-top, padding-bottom, padding-left, and padding-right. You

may set these values to px, em, percentages, or any other valid length unit.

Let’s take a look at an example. Example 3.19, “Non-uniform Padding” specifies two CSS rules:

• The first rule applies to all div elements, and changes the background, the text color, and

the font family. The gray background is necessary so that we can easily see padding for all

divs, while the other two properties are purely cosmetic.

• The second rule applies only to div elements with a class of padded. Any div with this

class will have special, non-uniform padding.

Example 3.19. Non-uniform Padding

1. <html>

2. <head>

3. <style>

4. div {

5. background: #444;

6. color: white;

7. }

9. div.padded {

10. padding-top: 10px;

11. padding-right: 0px;

12. padding-bottom: 0.25in;

13. padding-left: 5em;

14. }

15. </style>

16.</head>

17.<body>

18. <div>

19. No padding (but some style added)

20. </div>

21. <br>

22. <div class="padded">

23. Padded<br>

24. Top: 10px; bottom: 0px<br>

25. Left: 5em; right: 0px

26. </div>

27.</body>

28.</html>

The example includes a padded div, followed an ordinary div for comparison. The padded div has

padding that varies for each side of text, as we specified. It turns out that 5em (”five m-widths”) is

considerably larger than 10px, so the text looks shoved over to the right. As for the ordinary div, we

didn’t specify any padding rules for it, so it takes the browser default padding: 0px on all sides.

Padding Shorthand Notation

There is also a shorthand property, padding. This property allows you to specify all your padding

on one line:

• padding: 20px — Padding for all four sides is 20 pixels.

• padding: 20px 80px — Padding for the top and bottom is 20 pixels, the left and right

is 80 pixels.

• padding: 20px 80px 10px — Padding for the top is 20 pixels, the left and right is 80

pixels, and the bottom is 10 pixels.

• padding: 20px 80px 10px 40px — Padding for the top is 20 pixels, the right is 80

pixels, the bottom is 10 pixels, and the left is 40 pixels.

As with the previous example, Example 3.20, “Shorthand Padding” provides basic styling for all

divs, and then uses classes to change the padding for specific divs. For additional decoration,

we’ve also added a dark red border to each div.

Example 3.20. Shorthand Padding

1. <html>

2. <head>

3. <style>

4. div {

5. background: #444;

6. color: white;

7. border: #600 6px ridge;

8. }

10. div.one {

11. padding: 20px;

12. }

13.

14. div.two {

15. padding: 20px 80px;

16. }

17.

18. div.three {

19. padding: 20px 80px 10px;

20. }

21.

22. div.four {

23. padding: 20px 80px 10px 40px;

24. }

25. </style>

26.</head>

27.<body>

28. <div class="one">

29. padding: 20px (all)

30. </div>

31. <br>

32. <div class="two">

33. padding: 20px 40px (top/bottom, right/left)

34. </div>

35. <br>

36. <div class="three">

37. padding: 20px 40px 10px (top, right/left, bottom)

38. </div>

39. <br>

40. <div class="four">

41. padding: 20px 40px 10px 30px (top, right, bottom, left)

42. </div>

43.</body>

44.</html>

The padding is completely contained within the borders. For example, the inside edge of the first

div’s border is 20px from the far left edge of the text. Try changing the size of the borders. Even if

you make the border very thick, the padding stays the same thickness.

Of these four notations, the first (same padding for all sides) is the most commonly used and the

easiest to remember. However, if you want to baffle and impress your web designer friends, you

should memorize all four.

Margins

Margins are similar to padding. There are four margin properties: margin-top, marginbottom,

margin-left, and margin-right. There is also a shorthand property, margin,

which uses the same syntax as the padding property .

The key difference between margins and padding is that padding adds extra space inside the border,

while margins add extra space outside the border:

Example 3.21. Two Margin Blocks

1. <html>

2. <head>

3. <style>

4. div.even {

5. background: #cfc;

6. border: 1px solid;

7. padding: 5px;

8. margin: 40px;

9. }

10.

11. div.uneven {

12. background: #fcf;

13. border: 1px solid;

14. padding: 5px;

15. margin-top: 20px;

16. margin-right: 10px;

17. margin-bottom: 40px;

18. margin-left: 80px;

19. }

20. </style>

21.</head>

22.<body>

23. <div class="even">

24. margin: 40px (all)<br>

25. padding: 5px (all)

26. </div>

27. <div class="uneven">

28. margin-top: 40px<br>

29. margin-right: 30px<br>

30. margin-left: 20px<br>

31. margin-bottom: 10px<br>

32. padding: 5px (all)

33. </div>

34.</body>

35.</html>

We’ve set the padding to a uniform 5px, and we’ve set the background color to provide a little

contrast. The first box’s margin is set to a uniform 40px. The second box’s margin is set to four

different values. (The equivalent shorthand setting is “margin: 20px 10px 40px 80px”.)

Collapsing Margins

Without a border, it’s hard to tell the difference between the padding and the margin. One key

difference is that the element’s background color applies to the padding, but not the margin. Another

key difference is that vertical margins collapse.

At first glance you might guess that in Example 3.21, “Two Margin Blocks”, the vertical separation

between the two inner blocks would be 60px: 40px for the bottom margin of the first block plus

20px for the top margin of the second block. However, the margins collapse to 40px.

To simplify things greatly, margin collapse occurs when:

• the margins are vertical (horizontal margins never collapse)

• and:

• the blocks are directly adjacent (if there is anything between the blocks, the margins

do not collapse)

• or the blocks are nested and the parent block has no vertical borders or padding (if

the parent block has vertical borders or padding, the margins do not collapse. For an

example, refer to “Fancier Blockquotes”)

• and the blocks are left in the normal “flow” of the page (something you only need to worry

about when using CSS for more advanced things, such as page layout)

Margin collapsing sounds pretty complicated, and it is. You might be wondering why it’s there in

the first place.

Suppose we lived in a world where there is no such thing as margin collapsing. If we had a

sequence of five paragraphs, and we want even spacing of, say, 10px between each paragraph, how

would we achieve this, exactly? In short, you’re not going to get nice spacing without a lot of handtweaking.

• If each paragraph has a top and bottom margin of 10px, then the margin at the top and

bottom of the group of paragraphs would be 10px (good), but the spacing in between each

paragraph would be 20px (bad).

• Okay, what if we just specify margin-bottom as 10px, and leave margin-top as 0px?

That’s better, but we still would have a problem at the very top, where the first paragraph

butts up against the top of the page (or whatever is above the paragraph).

• Specifying margin-top as 10px creates a similar problem: there would be no spacing

between the bottom of the last paragraph and the top of the next element.

Back in the real world, margin collapsing is in effect, and so the aforementioned problem doesn’t

exist. If you write a bunch of paragraphs in a row, the browser just “does the right thing”, collapsing

margins so that even though each paragraph defines a top and bottom margin, the space between

paragraphs doesn’t get doubled.

Styling with the Box Model

Now that we’ve covered the components of the box model, you might be thinking, “Sure, it’s nice

that you can surround every paragraph with a bright lavender ridged border, but is that really all that

practical?” Let’s step through a couple of more real-world examples.

Text Decoration with Borders

Selective borders enable you to add styling to inline text that you couldn’t ordinarily apply. As an

example, one popular convention on the Web is to style abbr with a dotted underline. It would be

nice if we could use text-decoration to simulate this effect. Creating a dotted underline using

text-decoration might be possible in the future, but at the time of this writing this CSS

feature is still in draft status. However, we can use borders to work around this problem:

Example 3.22. Dotted Underline

1. <html>

2. <head>

3. <style>

4. abbr {

5. border-bottom: 1px #000000 dotted;

6. }

7. </style>

8. </head>

9. <body>

10. <p>

11. When my

12. <abbr

13. title="Person of Opposite Sex Sharing Living Quarters"

14. >POSSLQ</abbr>

15. and I went

16. <abbr

17. title="Self-Contained Underwater Breathing Apparatus"

18. >SCUBA</abbr>

19. diving yesterday, we were attacked by

20. <abbr

21. title="North Atlantic Treaty Organization">NATO</abbr>-controlled

22. sharks with frickin'

23. <abbr

24. title="Light Amplification by Stimulated Emission of Radiation"

25. >LASER</abbr>

26. beams attached to their heads.

27. </p>

28.</body>

29.</html>

Once the latest CSS specification solidifies, the browsers will be able to follow suit and implement

true dotted underlines, and the recipe above will become obsolete.

Fancier Blockquotes

The blockquote element is for quoted text that consists of one or more full paragraphs. By

default, blockquote indents everything to the right. In the past, people abused blockquote (and

ul and ol) to simply indent text. But there are much better ways to indent text, and so it’s best to

use blockquote for its original purpose: quoting paragraphs of text.

Let’s say that simply indenting the text is too plain. We’d like to add some color. In Example 3.23,

“Blockquotes”, we change the appearance of the blockquote element step-by-step until we

achieve the desired effect.

Example 3.23. Blockquotes

1. <html>

2. <head>

3. <style>

4. blockquote { background: #ccccff; }

5. blockquote.padded { padding: 3px; }

6. blockquote.bordered { padding: 3px; border-left: 3px #0000cc solid; }

7. blockquote.bordered p { margin: 10px; }

8. </style>

9. </head>

10.<body>

11. <blockquote>

12. <p>"I also have a paper afloat, with an electromagnetic theory of light,

13. which till I am convinced to the contrary, I hold to be great guns."</p>

14. </blockquote>

15. <p>- James Clerk Maxwell</p>

16.

17. <blockquote class="padded">

18. <p>"An expert is a person who has made all the mistakes that

19. can be made in a very narrow field."</p>

20. <p>"Your theory is crazy, but it's not crazy enough to be true."

21. </blockquote>

22. <p>- Niels Bohr</p>

23.

24. <blockquote class="bordered">

25. <p>[As a student, attending a lecture by Einstein]

26. "You know, what Mr. Einstein said is not so stupid..."</p>

27. <p>[On his wife leaving him for a chemist]

28. "Had she taken a bullfighter, I would have understood, but an

29. ordinary chemist..."</p>

30. </blockquote>

31. <p>- Wolfgang Pauli</p>

32.</body>

33.</html>

1. blockquote { background: #ccccff; }

First, we try setting the background to pale blue. Unfortunately, since the blockquote has no

padding, the colored space looks crowded.

2. blockquote.padded { padding: 3px; }

Next, we’ll try fixing this up by creating a new class, padded. This class inherits the

background color assigned to all blockquotes, and includes a little extra padding so that

the child paragraphs don’t look so crowded. Whoops! A whole lot of extra space appears

above and below the paragraphs. This looks even worse. What happened?

Adding padding to blockquote has triggered an interesting side-effect of the rules for

collapsing margins. As soon as you add padding or borders to the parent blockquote

element, margin collapsing goes away. This causes the paragraph’s margins to suddenly push

out the blockquote above and below.

3. blockquote.bordered { padding: 3px; border-left: 3px #0000cc

solid; }

Let’s try one more time. We’ll create another class, bordered, that includes the padding

and adds a decorative dark blue border to the left side of the blockquote.

4. blockquote.bordered p { margin: 10px; }

Finally, we’ll try to account for the problem introduced by the padding. The selector

blockquote.bordered p directs the browser to “apply this style to all p elements that

are inside a blockquote with a class of bordered.” As a quick fix, we’ll assign these

paragraphs a uniform margin of 10px. This pushes the paragraphs out to the right, and

provides a more uniform spacing around each paragraph. The spacing between each

paragraph is 10px, while the spacing between the blockquote and the paragraphs is 13px.

To make the spacing even more uniform, you could reduce the blockquote padding to

1px, or play a few more tricks with margins and padding, but let’s move on.

Align and Indent

You’ve probably noticed that most of your HTML paragraphs don’t have an initial indentation. You

can use margin or padding to push paragraphs to the right, but that affects the entire paragraph,

not just the first line. Furthermore, text is always left-aligned. How do we make centered text, or

right-aligned text?

As we saw in the “Borders” section, the box model controls the area around the text. This section

shows how to move the text around inside the box itself.

Indenting Text

To indent text, use the handily-named text-indent property. The following CSS snippet adds a

2.0 em indent to all paragraphs:

Example 3.24. Indented Paragraphs

1. <html>

2. <head>

3. <style>

4. p {

5. text-indent: 2.0em;

6. }

7. </style>

8. </head>

9. <body>

10. <p>

11. "On the contrary," said Holmes, quietly, "I have every reason

12. to believe that I will succeed in discovering Mr. Hosmer Angel."

13. </p>

14. <p>

15. Mr. Windibank gave a violent start, and dropped his gloves.

16. "I am delighted to hear it," he said.

17. </p>

18. <p>

19. "It is a curious thing," remarked Holmes, "that a typewriter

20. has really quite as much individuality as a man's handwriting.

21. Unless they are quite new no two of them write exactly alike.

22. Some letters get more worn than others, and some wear only on

23. one side. Now, you remark in this note of yours, Mr. Windibank,

24. that in every case there is some little slurring over the e, and

25. a slight defect in the tail of the r. There are fourteen other

26. characteristics, but those are the more obvious."

27. </p>

28.</body>

29.</html>

If you enter a negative value for text-indent, the first line of the text will shift to the left. This

is useful for creating “hanging indents” for headings and the like. The only trick is that you must set

the padding of containing block accordingly.

Example 3.25. Hanging Indent

1. <html>

2. <head>

3. <style>

4. div {

5. padding-top: 5px;

6. padding-bottom: 5px;

7. padding-right: 5px;

8. padding-left: 30px;

9. border: 3px solid;

10. }

11. h2 {

12. text-indent: -25px;

13. }

14. </style>

15.</head>

16.<body>

17. <div>

18. <h2>The Red-Headed League</h2>

19. <p>

20. I had called upon my friend, Mr. Sherlock Holmes, one

21. day in the autumn of last year, and found him in deep

22. conversation with a very stout, florid-faced elderly

23. gentleman, with fiery red hair. With an apology for my

24. intrusion, I was about to withdraw, when Holmes pulled

25. me abruptly into the room and closed the door behind me.

26. </p>

27. </div>

28.</body>

29.</html>

The “container” div has a uniform padding of 5px all around, except for the left padding, which is

30px. The h2 element has its text-indent set to negative 25px. The result is that the h2 shifts 30px

to the right due to the padding, and then shifts 25px back to the left due to the negative textindent.

All other elements are 30px from the left edge. The result is a 25px hanging indent.

Horizontal Alignment

The text-align property allows you to align text to the right, left, or center within its containing

block. The four options are:

• left: Aligns the text along the left edge of the box, leaving a ragged edge to the right. This

is the default.

• center: Centers the text within the box.

• right: Aligns the text along the right edge of the box, leaving a ragged edge to the left.

• justify: Aligns the text along both the right and left edges of the box. This can cause the

word spacing in the line to become uneven. The justify option isn’t as well-supported in

some older browsers.

Let’s take a look at all four options:

Example 3.26. Left, Center, Right, and Justified

1. <html>

2. <head>

3. <style>

4. div { border: 3px solid; padding: 5px; }

5. div.left { text-align: left; background: #ffcccc; }

6. div.center { text-align: center; background: #ccffcc; }

7. div.right { text-align: right; background: #ccccff; }

8. div.justify { text-align: justify; background: #ffffcc; }

9. </style>

10.</head>

11.

12.<body>

13. <div class="left"><em>Left-aligned text.</em></div>

14.

15. <div class="center"><em>Centered text.</em></div>

16.

17. <div class="right"><em>Right-aligned text.</em></div>

18.

19. <div class="justify"><em>Justified text.</em> Upon this a question

20. arises: whether it be better to be loved than feared or feared than

21. loved? It may be answered that one should wish to be both, but, because

22. it is difficult to unite them in one person, it is much safer to be

23. feared than loved, when, of the two, either must be dispensed with.

24. Because this is to be asserted in general of men, that they are

25. ungrateful, fickle, false, cowardly, covetous, and as long as you

26. succeed they are yours entirely; they will offer you their blood,

27. property, life, and children, as is said above, when the need is far

28. distant; but when it approaches they turn against you.</div>

29.</body>

30.</html>

Keep in mind that text-align aligns text and other inline content within boxes. It does not affect

blocks themselves. For example, you can’t use text-align: center to center a smaller box

within a larger box. This sort of thing is part of a more advanced concept called CSS positioning.

Tables

Tables enable you to arrange HTML elements in a grid. Examples of tabular data include calendars,

project resource assignments, scientific data sets, and other types of data that make sense to display

in rows and columns.

Note

Since tables can arrange HTML elements in a grid, one obvious usage for tables is to define the

layout of a web page. This ancient layout technique is now superseded by CSS-based layouts. For

brevity, this tutorial only focuses on tables that display tabular data.

When you’re done with this section, you should be able to:

• Create a basic table with cells containing tabular data

• Add captions and summaries

• Change the padding, margins, and borders of table cells using CSS

• Define more structured tables with column groups, footers, and headers

Section Summaries

The Tables chapter contains these sections:

• Table Structure — Explains how to construct a simple table by adding rows, columns, and

captions.

• Cellpadding and Cellspacing — Explains how to control the borders and spacing around

table cells using the border, cellpadding, and cellspacing attributes.

• Tables and CSS — Explains how to control the borders and spacing around table cells using

CSS.

Table Structure

Even a simple table involves several levels of nested elements. A table’s basic structure is:

• The table element defines the table itself.

• Within the table are one or more tr elements that define table rows.

• Within the tr elements are one or more th or td elements. These elements define table

header cells and table data cells, respectively.

Here’s a simple example of a table with one row and two columns. To better illustrate the structure

of the table, we’ve added a snippet of CSS to provide each table cell with a border.

Example 4.1. 1×2 Table

1. <html>

2. <head>

3. <title>1x2 Table</title>

4. <style>

5. td { border: 1px solid #000000; }

6. </style>

7. </head>

8. <body>

9. <table>

10. <tr>

11. <td>California</td>

12. <td>Michigan</td>

13. </tr>

14. </table>

15.</body>

16.</html>

Adding Rows and Columns

A tr element represents a row. To add another row, just add another tr element with the same

number of tds (columns) as the rest of the table:

Example 4.2. 2×2 Table

1. <table>

2. <tr>

3. <td>California</td>

4. <td>Michigan</td>

5. </tr>

6. <tr>

7. <td>Nevada</td>

8. <td>Ohio</td>

9. </tr>

10.</table>

A td represents a table data cell. To add another column, add another td element to each tr in the

table:

Example 4.3. 2×3 Table

1. <table>

2. <tr>

3. <td>California</td>

4. <td>Michigan</td>

5. <td>Mississippi

6. </tr>

7. <tr>

8. <td>Nevada</td>

9. <td>Ohio</td>

10. <td>Alabama</td>

11. </tr>

12.</table>

Adding Headers

So far, we’ve seen table rows containing td (table data) elements. However, rows can also contain

th (table header) elements. Table headers label a row or column. By default, most browsers render

table headers as bold.

Example 4.4. Table with Headers

1. <table>

2. <tr>

3. <th>West</th>

4. <th>Midwest</th>

5. <th>South</th>

6. </tr>

7. <tr>

8. <td>California</td>

9. <td>Michigan</td>

10. <td>Mississippi

11. </tr>

12. <tr>

13. <td>Nevada</td>

14. <td>Ohio</td>

15. <td>Alabama</td>

16. </tr>

17.</table>

Tip

If you leave any table data or table header empty (<td></td>), the cell will collapse and look

unattractive. To prevent this from happening, you can place a special “non-breaking space” entity,

 , in the cell. This inserts an invisible character that forces the browser to draw the borders

of the cell.

Adding Captions and Summaries

You can provide additional information about a table by giving it a caption or a summary.

The table element’s summary attribute provides a short text summary of the table. Most

browsers do not display the summary directly, but screen readers and text-only browsers can

provide this text to their users. If you hover your mouse over the table, some browsers will display

the summary text as a tooltip.

The caption element, which must immediately follow the <table> open tag, provides the

table’s title. By default, the caption appears directly above the table. Some browsers display the

caption centered above the table, others display it left-aligned. You may use CSS to align and style

the caption accordingly.

Table Rows, Cells, and Headers

Once you have placed the (optional) <caption>, it’s time to start constructing the actual table.

Tables are composed of table rows (<tr>). Each pairing <tr>...</tr> defines a row.

Within each table row are one or more cells, which are either table data (<td>) or table headers

(<th>). Table header cells are supposed to contain “header” information, such as the title of a row

or colum. Table data cells are supposed to contain the data. Note that if you leave any table cell

completely empty (”<td></td>“), the cell will collapse and look unattractive. It’s best to put

something in a blank cell, even if it’s just a <br> element.

Let’s take a look at an example that incorporates all of these elements. The previous table had one

row and two columns. The following table has four rows and four columns.

Example 4.5. 4×4 Table

1. <table cellpadding="5" border="2"

2. summary="All 12 months, organized by season">

3. <caption>The Four Seasons</caption>

4. <tr>

5. <th>Spring</th>

6. <th>Summer</th>

7. <th>Fall</th>

8. <th>Winter</th>

9. </tr>

10. <tr>

11. <td>March</td>

12. <td>June</td>

13. <td>September</td>

14. <td>December</td>

15. </tr>

16. <tr>

17. <td>April</td>

18. <td>July</td>

19. <td>October</td>

20. <td>January</td>

21. </tr>

22. <tr>

23. <td>May</td>

24. <td>August</td>

25. <td>November</td>

26. <td>February</td>

27. </tr>

28.</table>

As you can see, even a simple 4×4 table takes a fair amount of coding.

A few things to consider:

• Look carefully back and forth between the code and the results, and make sure that you

understand how each month ends up in the proper row and column. Do you understand why

there is one row of seasons and three rows of months? Do you understand why each column

of months lines up the way it does?

• The <th> text is bold, while the <td> is plain. This is the default font weight for these

elements, although of course you can change this with style sheets.

• The summary attribute does not appear anywhere on the screen. It’s really meant for nongraphical

browsers, but we’ll keep being a good citizen and continue to put it in.

Cellpadding and Cellspacing

The <table> element has three attributes that provide some basic control over the spacing around

table cells: border, cellpadding, and cellspacing. These three table attributes are similar

to the CSS properties border, padding, and margin. Let’s see how they work.

First we’ll create a table with no borders, cellpadding, or cellspacing. In order to make things easier

to see, we’ll use CSS to color the background of the table (green) and the individual table cells

(yellow).

Example 4.6. Table: No Spacing

1. <html>

2. <head>

3. <style>

4. table { background: #009900; }

5. td { background: #ffff00; }

6. </style>

7. </head>

8. <body>

9. <table

10. border="0" cellpadding="0" cellspacing="0"

11. summary="No padding, spacing, or borders">

12. <tr>

13. <td>Left Cell</td>

14. <td>Middle Cell</td>

15. <td>Right Cell</td>

16. </tr>

17. </table>

18.</body>

19.</html>

With no border, cellspacing, or cellpadding, our three cells are so cramped that we can’t see the

green background of the table — just the yellow background of the individual cells. Let’s try setting

each of these attributes to "5" five pixels) separately. We’ll maintain the same green and yellow

coloring scheme.

Example 4.7. Table: 5px Spacing

1. <html>

2. <head>

3. <style>

4. table { background: #009900; }

5. td { background: #ffff00; }

6. </style>

7. </head>

8. <body>

10. <h4>5px Border</h4>

11. <table

12. border="5" cellpadding="0" cellspacing="0"

13. summary="Table with a 5px border">

14. <tr>

15. <td>Left Cell</td>

16. <td>Middle Cell</td>

17. <td>Right Cell</td>

18. </tr>

19. </table>

20.

21. <h4>5px Cellpadding</h4>

22. <table

23. border="0" cellpadding="5" cellspacing="0"

24. summary="Table with 5px cellpadding">

25. <tr>

26. <td>Left Cell</td>

27. <td>Middle Cell</td>

28. <td>Right Cell</td>

29. </tr>

30. </table>

31.

32. <h4>5px Cellspacing</h4>

33. <table

34. border="0" cellpadding="0" cellspacing="5"

35. summary="Table with 5px cellspacing">

36. <tr>

37. <td>Left Cell</td>

38. <td>Middle Cell</td>

39. <td>Right Cell</td>

40. </tr>

41. </table>

42.

43.</body>

44.</html>

What are the results?

• In the first table, border="5". We see a five-pixel border around the edge of the table.

• In the second table, cellpadding="5". The size of each cell has expanded by five pixels

in every direction.

• In the third table, cellspacing="5". Each cell is separated from its neighbors by five

pixels. This spacing enables us to see the green background of the table itself.

Finally, let’s set all three attributes. We’ll set the border to 5px, the cellspacing to 10px, and the

cellpadding to 20px.

Example 4.8. Table: Variable Spacing

1. <html>

2. <head>

3. <style>

4. table { background: #009900;}

5. td { background: #ffff00; }

6. </style>

7. </head>

8. <body>

9. <table

10. border="5" cellpadding="20" cellspacing="10"

11. summary="Table with a 5px border,

12. 20px cellpadding, and 10px cellspacing">

13. <tr>

14. <td>Left Cell</td>

15. <td>Middle Cell</td>

16. <td>Right Cell</td>

17. </tr>

18. </table>

19.</body>

20.</html>

The ridged border around the table is five pixels wide, the cells are ten pixels apart, and the cells

themselves have twenty pixels of padding. Some browsers will display the border colored with the

background color, green; others will leave the ridged border colorless.

Tables and CSS

For more sophisticated control over borders, spacing, and padding, you can and should use CSS

rather than the border, cellspacing, and cellpadding attributes. The CSS properties are

as follows:

• The padding CSS property corresponds to the cellpadding table attribute.

• The border-spacing CSS property corresponds to the cellspacing table attribute.

• The border CSS property corresponds to the border table attribute.

The CSS properties allow us to use any valid CSS length: px are okay, as are em, pt, and so on.

We’ll stick with pixels for our example below.

Example 4.9. Table: CSS Borders

1. <html>

2. <head>

3. <style>

4. table {

5. background: #009900;

6. border: 4px #ff00ff ridge;

7. border-spacing: 5px;

8. }

9. td {

10. background: #ffff00;

11. padding: 10px;

12. border: 2px #0000ff dotted;

13. }

14. td.middle {

15. border: 2px #ff0000 solid;

16. padding-right: 25px;

17. }

18. </style>

19.</head>

20.<body>

21. <table

22. border="0" cellpadding="0" cellspacing="0"

23. summary="Table with CSS borders">

24. <tr>

25. <td>Left Cell</td>

26. <td class="middle">Middle Cell</td>

27. <td>Right Cell</td>

28. </tr>

29. </table>

30.</body>

31.</html>

The overall table has a green background and a ridged, lavender border. The result is garish to say

the least… presumably your tables will be far more subdued and tasteful.

Ordinary table cells have a yellow background, ten pixels of padding, five pixels of border-spacing

(i.e. cellspacing), and a blue, dotted border.

Table cells with class="middle" have an extra fifteen pixels of padding to the right and a red,

solid border.

Note that some modern browsers still don’t support the border-spacing attribute. If you’re

using one of these browsers, all three cells will be adjacent to each other, and you will not see the

green background of the table itself. One workaround is to use CSS to do your primary styling, and

the border table attribute for backup.

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