twitter bootstrap 3 code example

Example 1: boootstrap

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">

Example 2: Bootstrap

Bootstrap is a free and open-source CSS framework directed at responsive,
mobile-first front-end web development.

It contains CSS- and JavaScript-based design templates for typography, forms,
buttons, navigation, and other interface components.