<div class="container"> <div class="main">main</div> <div class="left">left</div> <div class="right">right</div> </div>
*{margin:0;padding:0;} .container { padding: 0 300px 0 200px; min-width:200px; } .left, .main, .right { position: relative; min-height: 130px; float: left; } .left { left: -200px; margin-left: -100%; background: green; width: 200px; } .right { right: -300px; margin-left: -300px; background-color: red; width: 300px; } .main { background-color: blue; width: 100%; }