To change column width based on screen size, the code is as follows −
Example
<!DOCTYPE html>
<html>
<head>
<style>
body {
font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}
.sample {
width: 50%;
background-color: lightblue;
height: 200px;
font-size: 18px;
}
@media only screen and (max-width: 700px) {
body {
margin: 0;
padding: 0;
}
.sample {
width: 100%;
}
}
</style>
</head>
<body>
<h1>Changing column width based on screen size</h1>
<div class="sample">Lorem ipsum dolor, sit amet consectetur adipisicing elit. Quod, maiores!</div>
<h3>Resize the browser window to 700px and below to see the above div width change to 100%</h3>
</body>
</html>Output
The above code will produce the following output −

On resizing the browser window to 700 px −
