Setup Bootstrap

  1. Web page must have html doctype
  2. Setup viewport in meta tag.
  3. Load bootsttrap css file.
  4. Load js scripts: jQuery, Popper and bootstrap in this order.

You can load files from cdn or you can have copy on your server.

<!doctype html>
<html lang="en">
  <head>
    <!-- Required meta tags -->
    meta charset="utf-8">
   <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
    
    <!-- Bootstrap CSS -->
    <link rel="stylesheet" 
        href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css"
        integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO"
        crossorigin="anonymous">

<!-- js files -->
    <script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" 
    integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo"
    crossorigin="anonymous"></script>
    
    <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js"
    integrity="sha384-ZMP7rVo3mIykV+2+9J3UJ46jBk0WLaUAdn689aCwoqbBJiSnjAK/l8WvCWPIPm49" 
    crossorigin="anonymous"></script>
    
    <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js"
    integrity="sha384-ChfqqxuZUCnJSK3+MXmPNIyE6ZbWh2IMqE241rYiqJxyMiZ6OW/JmZQ5stwEULTy"
    crossorigin="anonymous"></script>
  </head>
...