.ad_720x90 {
    background-image: url("../img/ads/banner720x90.png");
}

.ad_160x600 {
    background-image: url("../img/ads/banner160x600.png");
}

.ad_90x720 {
    background-image: url("../img/ads/banner90x720.png");
}

#horizontal_header {
    background: #96d3ff;
}