use percent in html div height code example
Example: css 100% height
<!DOCTYPE html>
<html>
<head>
<title>100% height</title>
<style>
html,
body {
height: 100%;
margin: 0;
}
.container {
height: 100%;
background: #000; /* to see the effect */
}
</style>
</head>
<body>
<div class="container"></div>
</body>
</html>