【media】
<!DOCTYPE html>
<html>
<head>
<style type='text/css'>
#left {
background: #f00;
height: 200px;
}
#right {
overflow: hidden;
background: #0f0;
height: 200px;
}
@media all and (min-width:600px) {
#left {
float: left;
width: 180px;
}
#right {
margin-left: 180px;
}
}
</style>
</head>
<body>
<div>
<div id="left">Nav</div>
<div id="right">This is the space I need to fill but not go
underneath the nav div</div>
</div>
</body>
</html>
