3.10. Cross-Platform Style Differences
After a few years of feeling their way around CSS implementation, the major browser vendors have produced reasonably well-behaved rendering engines since IE 5 (Windows and Mac), Opera 5, and Netscape 6. For the common style attributes in CSS1, you stand a good chance of achieving nearly identical output across these browsers.
Not that implementations are perfect. Even in recent browsers, some style attributes (float and overflow come to mind) can be neverending sources of cross-browser frustration. Assigning styles to complex hierarchical elements—especially deeply nested tables and lists—is a risky business, as inheritance chains mysteriously disconnect, and style attributes have minds of their own on some browser versions. Assuring consistent font sizes across browsers sometimes requires the equivalent of black magic.
Listing every browser's style sheet anomaly is beyond the scope of this book. Given all the content combinations and unexpected interactions, such an up-to-date master list probably doesn't exist. Always check the developer release notes for a browser. The open source Mozilla browser offers public access to the internal bug tracking system (Bugzilla), which may help you validate a problem you're experiencing with Netscape 6 or later. For other browsers, you'll have to rely on developer exchanges in the many online forums scattered across the Web.
That such inconsistencies exist points to the fact that deployment of CSS style sheets across all DHTML-capable browsers requires testing on as many browser brands and operating systems as you can get your hands on. Carefully study the output on each to make sure that your design goals are met, even if the exact implementations don't match pixel for pixel on the screen.
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