Create Windows 7 start menu using CSS3 only

I am fascinated with how much you can do with so little using CSS3. Many user interface elements that require images in order to have appropriate visual appearance now can be styled only with CSS3. In order to prove that I assigned myself a task to create Windows 7 start menu only with CSS3 (and some icons).

If we decompose the menu we'll get one div, two unordered lists with a couple of links each and a few icons. Let's see how each one of those is styled.
Check out the demo

Container

The container named startmenu holds two unordered lists that act as menus. It has linear gradient with three color stops: light blue at the top, dark blue in the middle, and another shade of light blue at the bottom. Transparency is achieved using rgba() which has four parameters. The first three represent red, green and blue color values and the last one is opacity. Two borders are created with border and box-shadow properties.

#startmenu { border:solid 1px #102a3e; overflow:visible; display:inline-block; margin:60px 0 0 20px;
             -moz-border-radius:5px;-webkit-border-radius:5px; position:relative;
             box-shadow: inset 0 0 1px #fff; -moz-box-shadow: inset 0 0 1px #fff; -webkit-box-shadow: inset 0 0 1px #fff;
             background-color:#619bb9;
             background: -moz-linear-gradient(top, rgba(50, 123, 165, 0.75), rgba(46, 75, 90, 0.75) 50%, rgba(92, 176, 220, 0.75));
             background: -webkit-gradient(linear, center top, center bottom, from(#327aa4),color-stop(45%, #2e4b5a), to(#5cb0dc)); }

Programs menu

This unordered list has white background and two borders created with border and box-shadow properties. Its links, which contain icons and program names, uses gradients and box shadows in hover state.

#programs, #links {float:left; display:block; padding:0; list-style:none;}
#programs { background:#fff; border:solid 1px #365167; margin:7px 0 7px 7px;
            box-shadow: 0 0 1px #fff; -moz-box-shadow: 0 0 1px #fff; -webkit-box-shadow: 0 0 1px #fff;
            -moz-border-radius:3px;-webkit-border-radius:3px;}
#programs a { border:solid 1px transparent; display:block; padding:3px; margin:3px; 
              color:#4b4b4b; text-decoration:none; min-width:220px;}
#programs a:hover {border:solid 1px #7da2ce; 
             -moz-border-radius:3px; -webkit-border-radius:3px;
             box-shadow: inset 0 0 1px #fff; -moz-box-shadow: inset 0 0 1px #fff; -webkit-box-shadow: inset 0 0 1px #fff;
             background-color:#cfe3fd;
             background: -moz-linear-gradient(top, #dcebfd, #c2dcfd);
             background: -webkit-gradient(linear, center top, center bottom, from(#dcebfd), to(#c2dcfd));}
#programs a img {border:0; vertical-align:middle; margin:0 5px 0 0;}             

Links menu

As in the previous case, links menu is quite simple. But the interesting part comes in hover state. Each link has horizontal gradient with three stops: dark blue on the left and right side, and a bit lighter blue in the middle. Now, unlike programs menu links, here, every links has inner <span> element which contains text. This span element has one more gradient - vertical linear gradient. It is transparent in the upper half and the lower part goes from very dark blue to almost transparent light blue. The combination of two transparent gradients gives exactly the same look as buttons in Windows 7 link menu.

#links {margin:7px; margin-top:-30px;}
#links li.icon {text-align:center;}
#links a {border:solid 1px transparent; display:block; margin:5px 0; position:relative;
              color:#fff; text-decoration:none; min-width:120px;}
#links a:hover {border:solid 1px #000;
             -moz-border-radius:3px; -webkit-border-radius:3px;
             box-shadow: 0 0 1px #fff; -moz-box-shadow: inset 0 0 1px #fff; -webkit-box-shadow: inset 0 0 1px #fff;
             background-color:#658da0;
             background: -moz-linear-gradient(center left, rgba(81,115,132,0.55), rgba(121,163,184,0.55) 50%, rgba(81,115,132,0.55));
             background: -webkit-gradient(linear, 0% 100%, 100% 100%, from(#517384), color-stop(50%, #79a3b8), to(#517384)); 
             }
#links a span { padding:5px; display:block; }
#links a:hover span  { background: -moz-linear-gradient(center top, transparent, transparent 49%, rgba(2,37,58,0.5) 50%, rgba(63,111,135,0.5));
            background: -webkit-gradient(linear, center top, center bottom, from(transparent), color-stop(49%, transparent), 
            color-stop(50%, rgba(2,37,58,0.5)), to(rgba(63,111,135,0.5))); }

Here is the preview, but I suggest you to check out the demo. You can play with backgrounds and see how transparency works.

The code works fine in Firefox 3.6+, Safari and Chrome. It degrades gracefully in Opera and IE. I guess I could optimize it a bit so if you have any suggestions please let me know.