Just read an interesting article over at jpsykes.com; testing css performance (pt 2). His conclusion is that using child selectors are slower than using direct class name declarations (in some browsers).
Head on over and read for yourself!
NOTE! Just noticed that part 3 of his testing css article series is out. Check it out.
I’m currently working on a webdesign with a centered div, and what’s really irritating is that in Firefox the entire div moves when the content goes below the screen length. Firefox shows the scrollbar and moves the entire page abit to the left. Why does it do that?? IE doesn’t! I have tried with the latest beta of Firefox 3, and same thing happens there.
If you want to test this yourself open this css layout over at Layout Gala in Firefox, and keep clicking the “Add Text to this section” link in the content area until the content goes below the screen length. When Firefox adds the scrollbar at the right side it shifts the entire page to the left.
Surely this must be a bug?
Update: I just checked using Opera and the same thing happens.
Update2: After googling around some, I found the solution to this “problem”.
The following CSS will make sure the vertical scrollbar are always present:
html {overflow-y: scroll;}
Glad I sorted that out! Now I can consentrate on the design again. 
Update3: This is still a “problem” in Opera. At least with version 9.27.
After the failure of getting Script Compressor to work, I decided to test out PHP Speedy by Leon Chevalier. A plugin that is suppose to to the same thing as Script Compressor.
There is one big difference though.. PHP Speedy works!
I timed the average load time of my blog page with, and without, the plugin activated. Here are the results:
| Without PHP Speedy | 1.12s |
| With PHP Speedy at default settings | 1.19s |
| With PHP Speedy, gzip page on, and footer text/image off | 0.97s |
As you can see the default settings didn’t work too well with me. But then again. I only have a small css file, and no javascript. Given a “heavier” site I think the default settings would work better. But as you see when I tweaked to settings a bit you see the plugin doing it’s job! Well done!
I downloaded and installed the Script Compressor plugin with the intent to check how much faster the blog would load with scripts compressed. I don’t have much javascript on my site, so I thought I would start out with just the css compression.
But I can’t see any difference in the css file. Isn’t it working? I’m checking the css using Firebug and the size stays the same, and the structure in the file is the same also. I thought the script was suppose to remove blank lines and comments etc, but all comments are intact in the file.
Am i using it wrong? Are there anyone out there that get this to work?