Question

How to give cross browser transparency to background only?

I want to give transparency to background of ul { background: } only don’t want to make text inside ul li a {} transparent.

ul {
    filter: alpha(opacity=50); /* internet explorer */
    -khtml-opacity: 0.5;      /* khtml, old safari */
    -moz-opacity: 0.5;       /* mozilla, netscape */
    opacity: 0.5;           /* fx, safari, opera */
}

this code make everything transparent http://perishablepress.com/press/2009/01/27/cross-browser-transparency-via-css/

Answer 1

you can use RGBA colors. I have made up an example for you:

http://jsfiddle.net/ypaTH/

ul {
 background: rgba(255, 255, 255, 0.5) //white with opcaity of 50%
}

ul li {
 color: #fff;
 background: rgba(0, 0, 0, 0.5) //black with opcaity of 50%
}

here is a workaround for IE and the compatibly list:
http://css-tricks.com/rgba-browser-support/