to get a mouseover effect on the Wallpaper Size Button - add an extra function to the css after:
.WallpaperSizeButton

so you have the following:

Code:

.WallpaperSizeButton{
color: #FFF;
background-color: #C33;
border: 1px solid #F60;
margin-right: 7px;
margin-left: 7px;
}

.WallpaperSizeButton:hover{
color: #C33;
background-color: #FFF;
border: 1px solid #006400;
margin-right: 7px;
margin-left: 7px;
}