Simplify jumbotron CSS

static/css/bootstrap-colors.css

@@ -1,7 +1,3 @@
-.jumbotron {
-    background-color:  var(--jumbotron-bg);
-}
-
 .btn-default {
     color: var(--btn-default-color);
     background-color: var(--btn-default-bg);

static/css/bootstrap.css

@@ -4089,7 +4089,7 @@ a.badge:focus {
   padding-bottom: 30px;
   margin-bottom: 30px;
   color: inherit;
-  background-color: #eeeeee;
+  background-color: var(--jumbotron-bg);
 }
 .jumbotron h1,
 .jumbotron .h1 {
@@ -4100,9 +4100,6 @@ a.badge:focus {
   font-size: 21px;
   font-weight: 200;
 }
-.jumbotron > hr {
-  border-top-color: #d5d5d5;
-}
 .container .jumbotron,
 .container-fluid .jumbotron {
   border-radius: 3px;

stuff/bootstrap/jumbotron.less

@@ -21,10 +21,6 @@
     font-weight: 200;
   }
 
-  > hr {
-    border-top-color: darken(@jumbotron-bg, 10%);
-  }
-
   .container &,
   .container-fluid & {
     border-radius: @border-radius-large; // Only round corners at higher resolutions if contained in a container

stuff/bootstrap/variables.less

@@ -487,7 +487,7 @@
 
 @jumbotron-padding:              30px;
 @jumbotron-color:                inherit;
-@jumbotron-bg:                   @gray-lighter;
+@jumbotron-bg:                   var(--jumbotron-bg);
 @jumbotron-heading-color:        inherit;
 @jumbotron-font-size:            ceil((@font-size-base * 1.5));
 @jumbotron-heading-font-size:    ceil((@font-size-base * 4.5));