I recently was doing some new skin for icelabz’s main page and as I am used to code making my pages xhtml 1.0 valid I thought every thing was going well. I was wrong, nowadays I lot of websites do have the xhtml 1.0 valid icon on them but not the CSS valid.
You see all browsers have a different way on interpreting css and all other markup languages. One of the most annoying browser is IE6. If you were to give that browser the command to go left it would go right, thats how I feel about the browser. My point is that each browser has a different way to react at the markup and css language you give them. Like for example this blog works fine in Opera, firefox and ie7 but not ie6.
On ie6 the site is just really messed up, that is because i am not using a valid css code. I will fix it soon though, when i get time.
So this mean even though you have the most strictest rule of xhtml run on that page it will still not look ok in at least 2-5% of the time on all browsers because we designers neglect the validity of the CSS.