Today, Your website must not look good only on desktop, but also on mobiles and tablets, your website must be responsive and able to adapt to the screen of the client.
To make your website responsive you need to use media queries and make all images and videos responsive and also ensure your typography will be easily readable on all devices.
But, before all that you need to add the responsive meta tags in your HTML document.
Here are the responsive meta tags you need to use inside the <head> tag:
<meta name="HandheldFriendly" content="True" />
<meta name="MobileOptimized" content="320" />
<meta name="viewport" content="width=device-width,minimum-scale=1.0, maximum-scale=1.0, user-scalable=no" />
<meta http-equiv="cleartype" content="on" />
<meta name="apple-mobile-web-app-capable" content="yes">
<meta name="apple-mobile-web-app-status-bar-style" content="black" />