calc - css

by redky

HTML

<div class="main"></div>
<div class="sidebar"></div>
<div class="ad"></div>

CSS

div {
    height: 100px;
    float: left;
}

.ad {
    width: 100px;
    background: #bbb;
}

.sidebar {
    width: 40%;
    background: #faa;
}

.main {
    width: -webkit-calc(60% - 100px );
    background: #eee;
}