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CSS: The Missing Manual, 4th Edition by David Sawyer McFarland

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Introduction

Cascading Style Sheets—CSS for short—give you creative control over the layout and design of your web pages. With CSS, dressing up your site’s text with eye-catching headlines, drop caps, and borders is just the beginning. You can also arrange images with precision, create columns and banners, and highlight your links with dynamic rollover effects. You can even make elements fade in or out of view, move objects around the page, or make a button slowly change colors when a visitor mouses over it.

Anything that can do all that must be pretty complicated, right? Au contraire! The whole idea behind CSS is to streamline the process of styling web pages. In the next few pages, you’ll learn about the basics of CSS.

What Is CSS?

CSS is a styling language. You use it to make HTML—the fundamental language of all web pages—look good. Well, hopefully, you’ll use CSS to make your web pages look better than good. After you read this book, you’ll be able to make your web pages beautiful, functional, and easy to use.

Think of HTML as the basic structure of your content, and CSS as a designer who takes your plain HTML and spruces it up with a fancy font, a border with rounded corners, or a bright red background.

But before you start learning about CSS, you need to understand HTML.

What You Need to Know

This book assumes you’ve already got some knowledge of HTML. Perhaps you’ve built a site or two (or at least a page or two) and have some familiarity with the sea of tags—<html>, <p>, <h1>, <table>—that make up the Hypertext Markup Language. CSS can’t do anything without HTML, so you need to know how to create a web page by using basic HTML.

If you’ve used HTML in the past to create web pages, but feel like your knowledge is a bit rusty, the next section provides a basic refresher.

Tip

If you’re just getting your feet wet learning HTML, then check out these free online tutorials: HTML Dog (www.htmldog.com/guides/htmlbeginner) and W3Schools (www.w3schools.com/html). If you’re a printed-page fan, then you may want to pick up a copy of HTML5: The Missing Manual, Third Edition or Head First HTML and CSS, Second Edition (both O’Reilly).

HTML: The Barebones Structure

HTML (Hypertext Markup Language) uses simple commands called tags to define the various parts of a web page. For example, this HTML code creates a simple web page:

<!doctype html>
<html>
  <head>
    <meta charset="UTF-8">
    <title>Hey, I am the title of this web page</title>
  </head>
  <body>
    <p>Hey, I am a paragraph on this web page.</p>
  </body>
</html>

It may not be exciting, but this example has all the basic elements a web page needs. You’ll notice something called a doctype declaration at the very beginning of the code, followed by <html> (with the brackets), a head, a body, and some stuff—the actual page contents—inside the body, ending in a final </html>.

Document Types

All web pages begin with a doctype—a line of code that identifies what flavor of HTML you used to write the page. Two doctypes have been used for years—HTML 4.01 and XHTML 1.0—and each of those doctypes has two styles: strict and transitional. For example, the HTML 4.01 transitional doctype looks like the following (the other doctypes for HTML 4.01 and XHTML 1.0 look similar):

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.
w3.org/TR/html4/loose.dtd">

Note

For examples of all various doctypes, visit www.webstandards.org/learn/reference/templates.

If you look at the code for the sample HTML page in this section, you’ll see that it uses a much more succinct doctype:

<!doctype html>

That’s the HTML5 doctype. HTML5 is easier to use and more streamlined than its predecessors. This book uses the HTML5 doctype, which is supported by every popular browser (even the old Internet Explorer 6). There’s no reason to use any doctype other than the simple HTML5 doctype.

Note

Just because the HTML doctype works in older browsers doesn’t mean that those browsers understand all HTML5 tags or features. Internet Explorer 8 and earlier, for example, don’t recognize the new HTML5 tags. To style tags with CSS for those versions of IE, you have to employ a little JavaScript. You’ll learn how to get older browsers up to speed in the box on Getting IE8 to Understand HTML5.

The most important thing about a doctype, however, is to always use one. Without it, your pages will look different depending on your visitor’s browser, since browsers display CSS differently if they don’t have a doctype for guidance.

Each doctype requires you to write your HTML in a certain way. For example, the tag for a line break looks like this in HTML 4.01:

<br>

But in XHTML, it looks like this:

<br />

And there’s another advantage of HTML5: It accepts either one.

How HTML Tags Work

In the simple HTML example on How HTML Tags Work, as in the HTML code of any web page, most commands appear in pairs that surround a block of text or other commands. Sandwiched between brackets, these tags are instructions that tell a web browser how to display the web page. Tags are the “markup” part of the Hypertext Markup Language.

The starting (opening) tag of each pair tells the browser where the instruction begins, and the ending tag tells it where the instruction ends. Ending or closing tags always include a forward slash (/) after the first bracket symbol (<).

On any web page, you’ll usually find at least these four elements:

  • The first line of a web page is the DOCTYPE declaration, discussed in the previous section.

  • The <html> tag appears once at the beginning of a web page and again (with an added forward slash) at the end: </html>. This tag tells a web browser that the information contained in this document is written in HTML, as opposed to some other language. All the contents of a page, including other tags, appear between the opening and closing <html> tags.

    If you were to think of a web page as a tree, the <html> tag would be its root. Springing from the trunk are two branches that represent the two main parts of any web page: the head and the body.

  • The head of a web page contains the title of the page (“Izzie’s Mail-Order Pencils”). It may also include other, invisible information, like a page description, that browsers and search engines use. You surround the head section with opening and closing <head> tags.

    In addition, the head section can include information that browsers use to format the page’s HTML and to add interactivity. As you’ll see, the <head> section can contain CSS code (like the kind you’ll learn to write in this book) or a link to another file containing CSS information.

  • The body, as set apart by its surrounding <body> tags, contains all the content that appears inside a browser window—headlines, text, pictures, and so on.

Within the <body> tag, you commonly find tags like these:

  • You tell a web browser where a paragraph of text begins with a <p> (opening paragraph tag), and where it ends with a </p> (closing paragraph tag).

  • The <strong> tag marks text as important. When you surround some text with it and its partner tag, </strong>, you get boldface type. The HTML snippet <strong> Warning!</strong> tells a web browser to strongly emphasize the word “Warning!”

  • The <a> tag, or anchor tag, creates a hyperlink in a web page. When clicked, a hyperlink—or link—can lead anywhere on the Web. You tell the browser where the link points by putting a web address inside the <a> tags. For instance, you can type <a href=“http://www.missingmanuals.com”>Click here!</a>.

    The browser knows that when your visitor clicks the words “Click here!” it should go to the Missing Manual website. The href part of the tag is called an attribute, and the URL (the Uniform Resource Locator, or web address) is the value. In this example, http://www.missingmanuals.com is the value of the href attribute.

HTML5: More Tags to Choose From

HTML5—the current version of HTML—has been around for years now. Sometimes you’ll hear the name used to describe things other than HTML tags, like local storage (a way to save data from a website to a visitor’s computer), geolocation (a way to check where a visitor is in the world), and drawing to the web page using WebGL. Strictly speaking, those technologies aren’t part of HTML, but they’re new browser features that came onto the scene along with HTML5.

In this book, the term HTML5 always refers to the HTML5 doctype as well as the new tags introduced as part of the HTML5 standard. HTML5 isn’t radically different from its predecessors—it was created to make sure the Web continues to work the way it always has. Most of the basics of HTML are the same as they’ve always been; HTML5 adds a few new elements meant to support the way web designers currently build websites. For example, in HTML5, the <header> tag contains the content you usually find at the top of a page, such as a logo and sitewide navigation links; the new <nav> tag encloses the set of links used to navigate a site; and the <footer> tag houses the stuff you usually put at the bottom of a page, like legal notices, email contacts, and so on.

In addition, HTML5 adds new tags that let you insert video and audio into a page, new form tags that add sophisticated elements like sliders and pop-up date pickers, and built-in browser support for form validation (which ensures visitors correctly fill out your forms). You’ll see HTML5 used throughout this book, especially in the next chapter.

Software for CSS

To create web pages made up of HTML and CSS, you need nothing more than a basic text editor like Notepad (Windows) or TextEdit (Mac). But after typing a few hundred lines of HTML and CSS, you may want to try a program better suited to working with web pages. This section lists some common programs, some free and some you have to buy.

Note

There are literally hundreds of tools that can help you create web pages, so the following isn’t a complete list. Think of it as a greatest-hits tour of the most popular programs that CSS fans are using today.

Free Programs

There are plenty of free programs out there for editing web pages and style sheets. If you’re still using Notepad or TextEdit, give one of these a try. Here’s a short list to get you started:

  • Brackets (Windows, Mac, Linux; http://brackets.io/). Spearheaded by Adobe, this free, open-source text editor has many tools for working with HTML and CSS. It’s written specifically for web designers and developers.

  • Atom (Windows, Mac, Linux; https://atom.io/). Another free, open-source text editor created by the people behind GitHub, the hugely popular code sharing and collaboration site. Like Brackets, this new text editor is aimed at web developers.

  • jEdit (Windows, Mac, Linux; http://jedit.org). This free, Java-based text editor works on almost any computer and includes many features that you’d find in commercial text editors, like syntax highlighting for CSS.

  • Notepad++ (Windows; http://notepad-plus.sourceforge.net). A lot of people swear by this fast text editor. It even has built-in features that make it ideal for writing HTML and CSS, like syntax highlighting—color-coding tags and special keywords to make it easier to identify the page’s HTML and CSS elements.

Commercial Software

Commercial website development programs range from inexpensive text editors to complete website construction tools with all the bells and whistles:

  • EditPlus (Windows; www.editplus.com) is an inexpensive ($35) text editor that includes syntax highlighting, FTP, autocomplete, and other wrist-saving features.

  • skEdit (Mac; www.skedit.com) is an inexpensive ($30) web page editor, complete with FTP/SFTP, code hints, and other useful features.

  • Coda2 (Mac; www.panic.com/coda) is a full-featured web development toolkit ($99). It includes a text editor, page preview, FTP/SFTP, and graphic CSS-creating tools for creating CSS.

  • Sublime Text (Mac, Windows, Linux; www.sublimetext.com) is a powerful text editor ($70) beloved by many web coders. You’ll find it frequently used in web design companies.

  • Dreamweaver (Mac and Windows; www.adobe.com/products/dreamweaver) is a visual web page editor (from $19.99 per month). It lets you see how your page looks in a web browser. The program also includes a powerful text editor and excellent CSS creation and management tools. Check out Dreamweaver CC: The Missing Manual for the full skinny on how to use this powerful program.

Note

The various types of software discussed in this section are general-purpose programs that let you edit both HTML and CSS. With them, you need to learn only one program for your web development needs.

About This Book

The World Wide Web is really easy to use. After all, grandfathers in Boise and first graders in Tallahassee log onto the Web every day. Unfortunately, the rules that govern how the Web works aren’t so easy to understand. The computer scientists and other techie types who write the official documentation aren’t interested in explaining their concepts to the average Joe (or Joanne). Just check out www.w3.org/TR/css3-transforms to get a taste of the technical mumbo-jumbo these geeks speak.

People just learning CSS often don’t know where to begin. And CSS’s finer points can trip up even seasoned web pros. The purpose of this book is to serve as the manual that should have come with CSS. In its pages, you’ll find step-by-step instructions for using CSS to create beautiful web pages.

CSS: The Missing Manual is designed to help readers at every technical level. To get the most out of this book, you should know the basics of HTML and maybe even a sampling of CSS. If you’ve never built a web page before, then check out the tutorial that starts on Tutorial: Creating Your First Styles. The primary discussions in these chapters are written for advanced beginners or intermediates. But if you’re new to building web pages, special boxes labeled “Up to Speed” provide the introductory information you need to understand the topic at hand. If you’re an advanced web jockey, on the other hand, then keep your eye out for similar boxes called “Power Users’ Clinic.” They offer more technical tips, tricks, and shortcuts for the experienced computer fan.

About the Outline

CSS: The Missing Manual is divided into five parts; the first four each contain several chapters while the last part contains appendixes.

  • Part 1, shows you how to create style sheets and provides an overview of key CSS concepts like inheritance, selectors, and the cascade. Along the way, you’ll learn the best HTML writing practices when working with CSS. Tutorials reinforce the part’s main concepts and give you a good taste of the power of CSS.

  • Part 2, takes you into the real world of web design. You’ll learn the most important CSS properties and how to use them to format text, create useful navigation tools, and enhance your page with graphics. You’ll learn how to create simple animations with CSS. This section also provides advice on how to make attractive tables and forms.

  • Part 3, helps you with one of the most confusing, but most rewarding, aspects of CSS—controlling the layout of your web pages. You’ll learn how to create common designs (like two- and three-column layouts) and how to add sidebars, and you’ll learn about floats and positioning—two common CSS techniques for controlling page layout. You’ll also learn how to craft websites that adapt to look good on desktop, tablet, and mobile browsers, as well as how to use flexbox, a powerful new way of laying out web pages.

  • Part 4, delves into professional tips for improving your CSS, It also provides an introduction to Sass—a powerful and efficient way of authoring your style sheets.

  • Part 5, includes two sets of resources. The CSS Property Reference summarizes each CSS property in small, easy-to-digest chunks so you can quickly learn about useful CSS properties you may not have seen before or brush up on what you already know. The second appendix covers tools and resources for creating and using CSS.

The Very Basics

To use this book, and indeed to use a computer, you need to know a few basics. You should be familiar with these terms and concepts:

  • Clicking. This book gives you three kinds of instructions that require you to use your computer’s mouse or trackpad. To click means to point the arrow cursor at something on the screen and then—without moving the cursor at all—to press and release the clicker button on the mouse (or laptop trackpad). A right-click is the same thing using the right mouse button. (On a Mac, press Control as you click if you don’t have a right mouse button.)

    To double-click means to click twice in rapid succession, again without moving the cursor at all. And to drag means to move the cursor while pressing the button.

    When you’re told to Ctrl-click something on a PC or ⌘-click something on the Mac, you click while pressing the Ctrl or ⌘ key.

  • Menus. The menus are the words at the top of your screen or window: File, Edit, and so on. Click one to make a list of commands appear, as though they’re written on a window shade you’ve just pulled down. This book assumes that you know how to open a program, surf the Web, and download files. You should know how to use the Start menu (Windows) or the Dock or the Apple menu (Mac), as well as the Control Panel (Windows) or System Preferences (Mac OS X).

  • Keyboard shortcuts. Every time you take your hand off the keyboard to move the mouse, you lose time and potentially disrupt your creative flow. That’s why many experienced computer users use keystroke combinations instead of menu commands wherever possible. When you see a shortcut like Ctrl+S (⌘-S) (which saves changes to the current document), it’s telling you to hold down the Ctrl or ⌘ key, and, while it’s down, type the letter S, and then release both keys.

About→These→Arrows

Throughout this book, and throughout the Missing Manual series, you’ll find sentences like this one: “Open the System→Library→Fonts folder.” That’s shorthand for a much longer instruction that directs you to open three nested folders in sequence, like this: “On your hard drive, you’ll find a folder called System. Open that. Inside the System folder window is a folder called Library; double-click it to open it. Inside that folder is yet another one called Fonts. Double-click to open it, too.”

Similarly, this kind of arrow shorthand helps to simplify the business of choosing commands in menus, as shown in Figure I-1.

In this book, arrow notations help simplify menu instructions. For example, View→Developer→View Source is a more compact way of saying, “From the View menu, choose Developer; from the submenu that then appears, choose View Source.”
Figure I-1. In this book, arrow notations help simplify menu instructions. For example, View→Developer→View Source is a more compact way of saying, “From the View menu, choose Developer; from the submenu that then appears, choose View Source.”

About the Online Resources

As the owner of a Missing Manual, you’ve got more than just a book to read. Online, you’ll find example files so you can get some hands-on experience, as well as tips, articles, and maybe even a video or two. You can also communicate with the Missing Manual team and tell us what you love (or hate) about the book. Head over to www.missingmanuals.com, or go directly to one of the following sections.

Living Examples

This book is designed to get your work onto the Web faster and more professionally. It’s only natural, then, that half the value of this book lies on the Web.

As you read the book’s chapters, you’ll encounter a number of living examples—step-by-step tutorials that you can build yourself, using raw materials (like graphics and half-completed web pages) that you can download from https://github.com/sawmac/css_mm_4e. You may not gain very much by simply reading these step-by-step lessons while relaxing in your porch hammock. But if you work through them at the computer, you’ll discover that these tutorials give you insight into the way professional designers build web pages.

You’ll also find, in this book’s lessons, the URLs of the finished pages, so that you can compare your work with the final result. In other words, you won’t just see pictures of how the web pages should look; you’ll find the actual, working web pages on the Internet.

About MissingManuals.com

At www.missingmanuals.com, you’ll find articles, tips, and updates to CSS: The Missing Manual. In fact, we invite and encourage you to submit such corrections and updates yourself. In an effort to keep the book as up-to-date and accurate as possible, each time we print more copies of this book, we’ll make any confirmed corrections you’ve suggested. We’ll also note such changes on the website, so that you can mark important corrections into your own copy of the book, if you like. (Go to www.missingmanuals.com/feedback, choose the book’s name from the pop-up menu, and then click Go to see the changes.)

Also on our Feedback page, you can get expert answers to questions that come to you while reading this book, write a book review, and find groups for folks who share your interest in CSS.

We’d love to hear your suggestions for new books in the Missing Manual line. There’s a place for that on missingmanuals.com, too. And while you’re online, you can also register this book at www.oreilly.com (you can jump directly to the registration page by going here: www.oreilly.com/register). Registering means we can send you updates about this book, and you’ll be eligible for special offers like discounts on future editions of CSS: The Missing Manual.

Errata

In an effort to keep this book as up-to-date and accurate as possible, each time we print more copies, we’ll make any confirmed corrections you’ve suggested. We also note such changes on the book’s website, so you can mark important corrections into your own copy of the book, if you like. Go to www.tinyurl.com/css4e-mm to report an error and view existing corrections.

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