<!DOCTYPE html>
<html>
<head>
<style type='text/css'>
#wrapper {
width: 100%;
height: 100px;
border: 1px dotted gray;
position: relative;
}
#left {
position: absolute;
right: 0;
top: 0;
bottom: 0;
width: 200px;
background-color: blue;
}
#right {
position: absolute;
left: 0;
right: 210px;
top: 0;
bottom: 0;
background-color: #5a71e5;
}
</style>
</head>
<body>
<div id="wrapper">
<div id="left"></div>
<div id="right"></div>
</div>
<p>And more content can follow...</p>
</body>
</html>