remove hella vars from the jumbotron

docs/components/jumbotron.md

@@ -10,9 +10,13 @@ A lightweight, flexible component that can optionally extend the entire viewport
 
 {% example html %}
 <div class="jumbotron">
-  <h1 class="jumbotron-heading">Hello, world!</h1>
+  <h1 class="display-3">Hello, world!</h1>
   <p class="lead">This is a simple hero unit, a simple jumbotron-style component for calling extra attention to featured content or information.</p>
-  <p class="lead"><a class="btn btn-primary btn-lg" href="#" role="button">Learn more</a></p>
+  <hr class="m-y-md">
+  <p>It uses utility classes for typography and spacing to space content out within the larger container.</p>
+  <p class="lead">
+    <a class="btn btn-primary btn-lg" href="#" role="button">Learn more</a>
+  </p>
 </div>
 {% endexample %}
 
@@ -21,19 +25,8 @@ To make the jumbotron full width, and without rounded corners, add the `.jumbotr
 {% example html %}
 <div class="jumbotron jumbotron-fluid">
   <div class="container">
-    <h1 class="jumbotron-heading">Fluid jumbotron</h1>
+    <h1 class="display-3">Fluid jumbotron</h1>
     <p class="lead">This is a modified jumbotron that occupies the entire horizontal space of it's parent.</p>
   </div>
 </div>
 {% endexample %}
-
-Jumbotrons also come with an adaptive `hr`—just add `.jumbotron-hr` to the element and the `border-top-color` will be tinted based on the jumbotron background.
-
-{% example html %}
-<div class="jumbotron">
-  <h1 class="jumbotron-heading">Jumbotron <code>hr</code></h1>
-  <p class="lead">This is a simple hero unit, a simple jumbotron-style component for calling extra attention to featured content or information.</p>
-  <hr class="jumbotron-hr">
-  <p class="lead"><a class="btn btn-primary btn-lg" href="#" role="button">Learn more</a></p>
-</div>
-{% endexample %}

docs/dist/css/bootstrap.css

@@ -589,7 +589,7 @@ hr {
   margin-top: 1rem;
   margin-bottom: 1rem;
   border: 0;
-  border-top: .0625rem solid #eceeef;
+  border-top: .0625rem solid rgba(0, 0, 0, .1);
 }
 
 small,
@@ -4578,15 +4578,10 @@ a.label:hover {
 .jumbotron {
   padding: 2rem 1rem;
   margin-bottom: 2rem;
-  color: inherit;
   background-color: #eceeef;
   border-radius: .3rem;
 }
 
-.jumbotron-heading {
-  color: inherit;
-}
-
 .jumbotron-hr {
   border-top-color: #d0d5d8;
 }
@@ -4595,9 +4590,6 @@ a.label:hover {
   .jumbotron {
     padding: 4rem 2rem;
   }
-  .jumbotron-heading {
-    font-size: 4.5rem;
-  }
 }
 
 .jumbotron-fluid {