BOOTSTRAP 4：Introduction - Bootstrap

bootstrap 4   bootstrap Learn how to use Bootstrap 4, the world’s most popular framework for responsive, mobile-first sites, with jsDelivr and a template starter page. Find out the page requirements, global styles, and components that need jQuery, Popper.js, and our own JavaScript plugins

bootstrap icon Download the SVG to use or edit. Using the web font? Copy, paste, and go. Paste the SVG right into your project's code

bootstrap modal Learn how to use Bootstrap's modal component to create pop-up windows with HTML, CSS, and JavaScript. See examples, options, and tips for scrolling, animation, and events