CSS: Style Sheet Guidelines (2)
What CSS looks like
- A Basic Style Sheet
- Note that the BODY declaration establishes the font family, text color, and background color. Any “child” of the BODY declaration (such as
<p>or<ol>or<blockquote>) will use these same fonts and colors unless the Style Sheet specifies otherwise. In CSS, this passing of characteristics from “parent” to “child” is called inheritance.
Notice also that browser offsets have been turned off via the margin and padding declarations. These declarations replace non-standard attributes to the HTML BODY tag, such as “marginheight” and “marginwidth,” which should never, never, never be used. - Redundant Selectors
- Notice that p and li reproduce the font-family information already declared by BODY. According to the rules of inheritance, this should not be necessary. Unfortunately, this redundancy is required to work around the defects of Netscape Navigator 4, which ignores inheritance because it lacks even the most basic CSS compliance.
- A Sophisticated Style Sheet (offsite link)
- Demonstrating how CSS can entirely replace (X)HTML table layouts. View alistapart.com in a CSS–capable browser (IE5+, Netscape 6+, Mozilla, Opera 5) to see how the Style Sheet creates the page layout. (View the same site in IE4 or Netscape 4 to see how the layout is hidden from those browsers, since they are incapable of reproducing it.)
CSS Usage at NYPL
View Source, and you'll see that this NYPL Style Guide has been laid–out entirely with CSS (no (X)HTML table hacks). Alas, for the foreseeable future, most Library projects will employ a combination of CSS and XHTML tables, in order to accommodate non-CSS-compliant browsers such as Netscape Navigator 4 and Microsoft Internet Explorer 4.
Tables and Accessibility
Although XHTML table layouts are less accessible than pure CSS layouts, and although they require additional markup (and thus use more bandwidth), it is entirely possible to create valid XHTML table layouts that work in combination with valid Style Sheets—and that is what this Style Guide recommends.
On the next page, we explore CSS resources to help you learn more. »
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