This site is designed with Bootstrap, about Bootstrap! It demonstrates the various capabilities of the framework.
In order to use Bootstrap, you need to import the CSS and Javascript code to your site. You can place them in the <head> tag.
Bootstrap is an easy to use, fast way to create websites alongside standard HTML and CSS.
Among many things, Bootstrap even has a large icon library for you to use on your site, complete with specific bran logos and different line weights.