Question

What are pros and cons

if i make 4 different css?

• main.css
• IE7.css ( in conditional comments)
• IE8.css ( in conditional comments)
• IE6.css ( in conditional comments)

OR

1 css file for all

• main.css + including hack for IE6 +
  IE 7 + IE8(if needed)

Answer 1

Pros:

1. Performance: Saves resources for non-IE browsers.
2. Validation: You can validate your CSS, and non-IE browsers does’nt have to handle non-valid CSS.
3. Cross-browser: supports IE 5.5 to IE 8 and probably newer versions.
4. Support: It’s officially supported by Microsoft, contrary to CSS hacks.

Cons:

1. Maintenance: You have to maintain more files.
2. Performance: IE will have to make more HTTP requests.
3. KISS: Sometimes it may be overkill, for one or two rules.

In general, I think conditional comments are better than CSS hacks.