HTML and CSS Reference
After running the Validation Service, it will return any errors found. If none are identified, it will let
you know that your CSS is valid and present you with a couple of badges that you can proudly dis-
play on your site (Figure 5-2). The CSS Validation Service will also warn you of any repetitive prop-
erty/value uses or if, for example, you haven't included a generic font at the end of your font-family
value. It is best to clear up any warnings to avoid potential problems.
cHeckinG your css in a browser
When web designers talk of “testing their CSS,” what do they mean? For the most part, you test a
page by simply viewing it in the browser. If there is a serious problem, it will jump out at you right
away. For example, older versions of Internet Explorer (versions 6 and below) handled a basic CSS
concept, the box model, differently from web standards-compliant browsers. In short, when you
specified a <div> tag's width , the prior editions of Internet Explorer (IE) potentially thought you
meant a larger amount of space than all the other browsers. In multiple column designs — which is
most of the Web — this led to one of the columns being squeezed out because IE thought the first
column was bigger than it actually was. This situation is immediately obvious when you look at
your page in an IE 6 or earlier browser.
Other design differences are not so obvious and may even be acceptable. The amount of browser
“chrome” (the various toolbars and interface elements surrounding the actual web page) varies from
browser to browser. A browser with more chrome will push your page down the document window,
but because it does the same to all pages, such an issue isn't critical and, I would argue, is a fact-of-
life on the Web.