Put the background-size, but it did not work.
*{ margin:0; padding:0; } div{ display:block; } body{ background-size: 100% 100%; background:url(images/bg.png); } header { height:8%; width: 100%; background-color: #FFF; margin: 0 auto; border-bottom: 1px solid #000; } .right{ float:left; background-color: #fff; width:15%; height:100%; } .menu{float:left; background-color:#fff; width:70%; height:100%; } .left{float:left; background-color: #fff; width:15%; height:100%; } img{ border:none; } ul{ margin-left:10%; width:80%; height:100%; background-color:#fff; list-style-type: none; } li { float: left; height: 90%; width:10%; background-color:#fff; text-align: center; line-height: 50px; } a { display: inline-block; width: 100%; height: 100%; text-decoration:none; color:#000; } .container{ }