I spent part of my day fighting with CSS for an email template. CSS support is poor in both desktop and web clients, and much worse than in current browsers.

Gmail, for example, does not support <style> in either the head or the body of HTML email. You have to explicitly set style attributes on individual nodes. You might as well be using <font> tags!

You can't assume that images will be downloaded, so the mail has to make sense without them. And forget iframes.

Cam­paign­Mon­i­tor seems to have the definitive guide to CSS support.

Cederholm clearly explains the CSS techniques required to build a "bul­let­proof" website: one that is robust in the face of text resizing, window resizing, disabled images, etc, with minimal, se­man­ti­cal­ly correct markup that works across all the major browsers.

Anyone who's serious about building a modern website should read this book.

Cederholm builds up his examples, one step at a time, in a clear manner. For the shorter examples, he tends to show the entire CSS or XHTML again and again, with the latest changes high­light­ed …continue.