TAILIEUCHUNG - Tự học HTML và CSS trong 1 giờ - part 21

Tham khảo tài liệu 'tự học html và css trong 1 giờ - part 21', công nghệ thông tin, đồ họa - thiết kế - flash phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 176 LESSON 8 Using CSS to Style a Site As you can see the capability to link to external style sheets provides you with a powerful means for managing the look and feel of your site. After you ve set up a sitewide style sheet that defines the styles for your pages changing things such as the headline font and background color for your pages all at once is trivial. Before CSS making these kinds of changes required a lot of manual labor or a facility with tools that had search and replace functionality for multiple files. Now it requires quick edits to a single-linked style sheet. Selectors You ve already seen one type of selector for CSS element names. Any tag can serve as a CSS selector and the rules associated with that selector will be applied to all instances of that tag on the page. You can add a rule to the b tag that sets the font weight to normal if you choose to do so or italicize every paragraph on your page by applying a style to the p tag. Applying styles to the body tag using the body selector enables you to apply pagewide settings. However you can apply styles on a more granular basis in a number of ways and to apply them across multiple types of elements using a single selector. First there s a way to apply styles to more than one selector at the same time. Suppose for instance that you want all unordered lists ordered lists and paragraphs on a page displayed using blue text. Instead of writing individual rules for each of these elements you can write a single rule that applies to all of them. Here s the syntax p ol ul color blue A comma-separated list indicates that the style rule should apply to all the tags listed. The preceding rule is just an easier way to write the following p color blue ol color blue ul color blue Contextual Selectors Contextual selectors are also available. These are used to apply styles to elements only when they re nested within other specified elements. Take a look at this rule ol em color blue The fact that I left out the .

• Đồ họa - Thiết kế - Flash
• tự học html và css
• html
• css
• tài liệu html và css
• thiết kế web với html và css