Add additional root variables, rename $variable-prefix to $prefix (#35981)

* Add additional root variables, rename $variable-prefix to $prefix

- Adds new root CSS variables for border-radius, border-width, border-color, and border-style
- Adds new root CSS variables for heading-color, link-colors, code color, and highlight color
- Replaces most instances of Sass variables (for border-radius, border-color, border-style, and border-width) for CSS variables inside _variables.scss
- Updates $mark-padding to be an even pixel number
- Renames $variable-prefix to $prefix throughout

* Bundlewatch

scss/_navbar.scss

@@ -5,26 +5,26 @@
 
 .navbar {
   // scss-docs-start navbar-css-vars
-  --#{$variable-prefix}navbar-padding-x: #{if($navbar-padding-x == null, 0, $navbar-padding-x)};
-  --#{$variable-prefix}navbar-padding-y: #{$navbar-padding-y};
-  --#{$variable-prefix}navbar-color: #{$navbar-light-color};
-  --#{$variable-prefix}navbar-hover-color: #{$navbar-light-hover-color};
-  --#{$variable-prefix}navbar-disabled-color: #{$navbar-light-disabled-color};
-  --#{$variable-prefix}navbar-active-color: #{$navbar-light-active-color};
-  --#{$variable-prefix}navbar-brand-padding-y: #{$navbar-brand-padding-y};
-  --#{$variable-prefix}navbar-brand-margin-end: #{$navbar-brand-margin-end};
-  --#{$variable-prefix}navbar-brand-font-size: #{$navbar-brand-font-size};
-  --#{$variable-prefix}navbar-brand-color: #{$navbar-light-brand-color};
-  --#{$variable-prefix}navbar-brand-hover-color: #{$navbar-light-brand-hover-color};
-  --#{$variable-prefix}navbar-nav-link-padding-x: #{$navbar-nav-link-padding-x};
-  --#{$variable-prefix}navbar-toggler-padding-y: #{$navbar-toggler-padding-y};
-  --#{$variable-prefix}navbar-toggler-padding-x: #{$navbar-toggler-padding-x};
-  --#{$variable-prefix}navbar-toggler-font-size: #{$navbar-toggler-font-size};
-  --#{$variable-prefix}navbar-toggler-icon-bg: #{escape-svg($navbar-light-toggler-icon-bg)};
-  --#{$variable-prefix}navbar-toggler-border-color: #{$navbar-light-toggler-border-color};
-  --#{$variable-prefix}navbar-toggler-border-radius: #{$navbar-toggler-border-radius};
-  --#{$variable-prefix}navbar-toggler-focus-width: #{$navbar-toggler-focus-width};
-  --#{$variable-prefix}navbar-toggler-transition: #{$navbar-toggler-transition};
+  --#{$prefix}navbar-padding-x: #{if($navbar-padding-x == null, 0, $navbar-padding-x)};
+  --#{$prefix}navbar-padding-y: #{$navbar-padding-y};
+  --#{$prefix}navbar-color: #{$navbar-light-color};
+  --#{$prefix}navbar-hover-color: #{$navbar-light-hover-color};
+  --#{$prefix}navbar-disabled-color: #{$navbar-light-disabled-color};
+  --#{$prefix}navbar-active-color: #{$navbar-light-active-color};
+  --#{$prefix}navbar-brand-padding-y: #{$navbar-brand-padding-y};
+  --#{$prefix}navbar-brand-margin-end: #{$navbar-brand-margin-end};
+  --#{$prefix}navbar-brand-font-size: #{$navbar-brand-font-size};
+  --#{$prefix}navbar-brand-color: #{$navbar-light-brand-color};
+  --#{$prefix}navbar-brand-hover-color: #{$navbar-light-brand-hover-color};
+  --#{$prefix}navbar-nav-link-padding-x: #{$navbar-nav-link-padding-x};
+  --#{$prefix}navbar-toggler-padding-y: #{$navbar-toggler-padding-y};
+  --#{$prefix}navbar-toggler-padding-x: #{$navbar-toggler-padding-x};
+  --#{$prefix}navbar-toggler-font-size: #{$navbar-toggler-font-size};
+  --#{$prefix}navbar-toggler-icon-bg: #{escape-svg($navbar-light-toggler-icon-bg)};
+  --#{$prefix}navbar-toggler-border-color: #{$navbar-light-toggler-border-color};
+  --#{$prefix}navbar-toggler-border-radius: #{$navbar-toggler-border-radius};
+  --#{$prefix}navbar-toggler-focus-width: #{$navbar-toggler-focus-width};
+  --#{$prefix}navbar-toggler-transition: #{$navbar-toggler-transition};
   // scss-docs-end navbar-css-vars
 
   position: relative;
@@ -32,7 +32,7 @@
   flex-wrap: wrap; // allow us to do the line break for collapsing content
   align-items: center;
   justify-content: space-between; // space out brand from logo
-  padding: var(--#{$variable-prefix}navbar-padding-y) var(--#{$variable-prefix}navbar-padding-x);
+  padding: var(--#{$prefix}navbar-padding-y) var(--#{$prefix}navbar-padding-x);
   @include gradient-bg();
 
   // Because flex properties aren't inherited, we need to redeclare these first
@@ -63,17 +63,17 @@
 // Used for brand, project, or site names.
 
 .navbar-brand {
-  padding-top: var(--#{$variable-prefix}navbar-brand-padding-y);
-  padding-bottom: var(--#{$variable-prefix}navbar-brand-padding-y);
-  margin-right: var(--#{$variable-prefix}navbar-brand-margin-end);
-  @include font-size(var(--#{$variable-prefix}navbar-brand-font-size));
-  color: var(--#{$variable-prefix}navbar-brand-color);
+  padding-top: var(--#{$prefix}navbar-brand-padding-y);
+  padding-bottom: var(--#{$prefix}navbar-brand-padding-y);
+  margin-right: var(--#{$prefix}navbar-brand-margin-end);
+  @include font-size(var(--#{$prefix}navbar-brand-font-size));
+  color: var(--#{$prefix}navbar-brand-color);
   text-decoration: if($link-decoration == none, null, none);
   white-space: nowrap;
 
   &:hover,
   &:focus {
-    color: var(--#{$variable-prefix}navbar-brand-hover-color);
+    color: var(--#{$prefix}navbar-brand-hover-color);
     text-decoration: if($link-hover-decoration == underline, none, null);
   }
 }
@@ -93,21 +93,21 @@
   .nav-link {
     padding-right: 0;
     padding-left: 0;
-    color: var(--#{$variable-prefix}navbar-color);
+    color: var(--#{$prefix}navbar-color);
 
     &:hover,
     &:focus {
-      color: var(--#{$variable-prefix}navbar-hover-color);
+      color: var(--#{$prefix}navbar-hover-color);
     }
 
     &.disabled {
-      color: var(--#{$variable-prefix}navbar-disabled-color);
+      color: var(--#{$prefix}navbar-disabled-color);
     }
   }
 
   .show > .nav-link,
   .nav-link.active {
-    color: var(--#{$variable-prefix}navbar-active-color);
+    color: var(--#{$prefix}navbar-active-color);
   }
 
   .dropdown-menu {
@@ -123,12 +123,12 @@
 .navbar-text {
   padding-top: $nav-link-padding-y;
   padding-bottom: $nav-link-padding-y;
-  color: var(--#{$variable-prefix}navbar-color);
+  color: var(--#{$prefix}navbar-color);
 
   a,
   a:hover,
   a:focus  {
-    color: var(--#{$variable-prefix}navbar-active-color);
+    color: var(--#{$prefix}navbar-active-color);
   }
 }
 
@@ -151,14 +151,14 @@
 
 // Button for toggling the navbar when in its collapsed state
 .navbar-toggler {
-  padding: var(--#{$variable-prefix}navbar-toggler-padding-y) var(--#{$variable-prefix}navbar-toggler-padding-x);
-  @include font-size(var(--#{$variable-prefix}navbar-toggler-font-size));
+  padding: var(--#{$prefix}navbar-toggler-padding-y) var(--#{$prefix}navbar-toggler-padding-x);
+  @include font-size(var(--#{$prefix}navbar-toggler-font-size));
   line-height: 1;
-  color: var(--#{$variable-prefix}navbar-color);
+  color: var(--#{$prefix}navbar-color);
   background-color: transparent; // remove default button style
-  border: var(--#{$variable-prefix}border-width) solid var(--#{$variable-prefix}navbar-toggler-border-color); // remove default button style
-  @include border-radius(var(--#{$variable-prefix}navbar-toggler-border-radius));
-  @include transition(var(--#{$variable-prefix}navbar-toggler-transition));
+  border: var(--#{$prefix}border-width) solid var(--#{$prefix}navbar-toggler-border-color); // remove default button style
+  @include border-radius(var(--#{$prefix}navbar-toggler-border-radius));
+  @include transition(var(--#{$prefix}navbar-toggler-transition));
 
   &:hover {
     text-decoration: none;
@@ -167,7 +167,7 @@
   &:focus {
     text-decoration: none;
     outline: 0;
-    box-shadow: 0 0 0 var(--#{$variable-prefix}navbar-toggler-focus-width);
+    box-shadow: 0 0 0 var(--#{$prefix}navbar-toggler-focus-width);
   }
 }
 
@@ -178,14 +178,14 @@
   width: 1.5em;
   height: 1.5em;
   vertical-align: middle;
-  background-image: var(--#{$variable-prefix}navbar-toggler-icon-bg);
+  background-image: var(--#{$prefix}navbar-toggler-icon-bg);
   background-repeat: no-repeat;
   background-position: center;
   background-size: 100%;
 }
 
 .navbar-nav-scroll {
-  max-height: var(--#{$variable-prefix}scroll-height, 75vh);
+  max-height: var(--#{$prefix}scroll-height, 75vh);
   overflow-y: auto;
 }
 
@@ -211,8 +211,8 @@
           }
 
           .nav-link {
-            padding-right: var(--#{$variable-prefix}navbar-nav-link-padding-x);
-            padding-left: var(--#{$variable-prefix}navbar-nav-link-padding-x);
+            padding-right: var(--#{$prefix}navbar-nav-link-padding-x);
+            padding-left: var(--#{$prefix}navbar-nav-link-padding-x);
           }
         }
 
@@ -280,12 +280,12 @@
 }
 
 .navbar-dark {
-  --#{$variable-prefix}navbar-color: #{$navbar-dark-color};
-  --#{$variable-prefix}navbar-hover-color: #{$navbar-dark-hover-color};
-  --#{$variable-prefix}navbar-disabled-color: #{$navbar-dark-disabled-color};
-  --#{$variable-prefix}navbar-active-color: #{$navbar-dark-active-color};
-  --#{$variable-prefix}navbar-brand-color: #{$navbar-dark-brand-color};
-  --#{$variable-prefix}navbar-brand-hover-color: #{$navbar-dark-brand-hover-color};
-  --#{$variable-prefix}navbar-toggler-border-color: #{$navbar-dark-toggler-border-color};
-  --#{$variable-prefix}navbar-toggler-icon-bg: #{escape-svg($navbar-dark-toggler-icon-bg)};
+  --#{$prefix}navbar-color: #{$navbar-dark-color};
+  --#{$prefix}navbar-hover-color: #{$navbar-dark-hover-color};
+  --#{$prefix}navbar-disabled-color: #{$navbar-dark-disabled-color};
+  --#{$prefix}navbar-active-color: #{$navbar-dark-active-color};
+  --#{$prefix}navbar-brand-color: #{$navbar-dark-brand-color};
+  --#{$prefix}navbar-brand-hover-color: #{$navbar-dark-brand-hover-color};
+  --#{$prefix}navbar-toggler-border-color: #{$navbar-dark-toggler-border-color};
+  --#{$prefix}navbar-toggler-icon-bg: #{escape-svg($navbar-dark-toggler-icon-bg)};
 }