There are two divs. I want second div to occupy the remaining space. Currently it is occupying 100% height but it should take only remaining space.
html, body {
  height: 100%;
  width: 100%;
}
.header {
  background-color: blue;
  color: red;
  font-size: 50px;
}
.content {
  background-color: red;
  height: 100%;
  width: 100%;
}<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
</head>
<body>
<div class="header">Header</div>
<div class="content">
  </div>
</body>
</html> 
    