You can give alpha transparency in the background color.
for instance
div {
background: rgba(255,255,255,0.5);
}
In IE, however, it rgbadoes not work. You need to use a filter.
Example
div {
background: transparent;
-ms-filter: "progid: DXImageTransform.Microsoft.gradient(startColorstr=#77ffffff, endColorstr=#77ffffff)";
filter: progid: DXImageTransform.Microsoft.gradient(startColorstr=#77ffffff, endColorstr=#77ffffff);
zoom: 1;
}
, rgba, ARGB . , ,
77: alpha (fully transparent: 00, fully opaque: FF)
ff: Red
ff: Green
ff: Blue
, , div , , opacity
div {
background: #fff;
opacity: 0.5;