<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>
<div class="left"></div>
<div class="center"></div>
<div class="right"></div>
</div>
</body>
</html>
<style>
.center,
.left,
.right {
float: left;
height: 200px;
}
.left,.right {
width: 200px;
}
.left {
background: red;
}
.right {
background: blue;
}
.center {
width: calc(100% - 400px);
background: yellow;
}
</style>
