August 2012
Beginner
583 pages
16h 1m
English
Content preview from Learning PHP, MySQL, JavaScript, and CSS, 2nd EditionBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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CSS Selectors
The means by which you access one or more elements on the page is called selection, and as we saw earlier, the part of a CSS rule that does this is known as a selector. As you might expect, there are many different varieties of selector.
The Type Selector
The type selector specifies the HTML element to style, such as
<p> or <i>. For example, the following rule
will ensure that all text within <p>...</p> tags is fully
justified:
p { text-align:justify; }The Descendant Selector
Descendant selectors let you apply styles to elements that are
contained within other elements. For example, the following rule sets
all text within <b>...</b> tags to red, but only
if they occur within <p>...</p> tags (like this:
<p><b>Hello</b>
there</p>):
p b { color:red; }Descendant selectors can continue nesting indefinitely, so the following is a perfectly valid rule to make bold text inside a list element of an unordered list appear in blue:
ul li b { color:blue; }As a practical example, suppose you want to use a different numbering system than the default for an ordered list that is nested within an unordered list. You can achieve this in the following way, which will replace the default numbering (starting from 1) with lowercase letters (starting from a):
<!DOCTYPE html>
<html>
<head>
<style>
ul ol { list-style-type:lower-alpha; }
</style>
</head>
<body>
<ol>
<li>One</li>
<li>Two</li>
<li>Three</li>
</ol>
<ul>
<ol>
<li>One</li>
<li>Two</li>
<li>Three</li>
</ol>
</ul>
</body>
</html>The result ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.