.container_12 {
    margin-left: auto;
    margin-right: auto;
    width: 960px;
    position: relative;
}

.grid_4,.grid_8 {
    display: inline;
    float: left;
    position: relative;
    margin-left: 10px;
    margin-right: 10px;
}

.alpha {
    margin-left: 0;
}

.omega {
    margin-right: 0;
}

.container_12 .grid_4 {
    width: 300px;
}

.container_12 .grid_8 {
    width: 620px;
}