adding bootstrap variables. (#45231)

Author: hiteshm0

build/media_source/templates/administrator/atum/scss/_variables-dark.scss

@@ -284,6 +284,7 @@ $atum-colors-dark: (
   btn-secondary-bg:                      $info-dark,
   btn-secondary-border:                  1px solid color.adjust($info-dark, $lightness: 10%),
   btn-secondary-bg-hvr:                  color.adjust($info-dark, $lightness: -10%),
+  btn-secondary-color-hvr:               var(--template-text-light),
   btn-secondary-border-hvr:              1px solid color.adjust($info-dark, $lightness: 10%),
 
   btn-dark-border:                     1px solid rgba(0,0,0,.85),

build/media_source/templates/administrator/atum/scss/_variables.scss

@@ -339,6 +339,8 @@ $atum-colors: (
   btn-secondary-bg:                 var(--template-bg-dark-60),
   btn-secondary-border:             1px solid var(--template-bg-dark-60),
   btn-secondary-color:              var(--template-text-light),
+  btn-secondary-bg-hvr:             var(--template-bg-dark-70),
+  btn-secondary-color-hvr:          var(--template-text-light),
 
   btn-info-color:                   var(--template-text-light),
   btn-info-bg:                      $info,

build/media_source/templates/administrator/atum/scss/vendor/bootstrap/_buttons.scss

@@ -54,8 +54,8 @@
   border: var(--btn-secondary-border);
 
   &:hover {
-    color: var(--btn-secondary-color-hvr);
-    background: var(--btn-secondary-bg-hvr);
+    color: var(--btn-secondary-color-hvr, var(--btn-secondary-color));
+    background: var(--btn-secondary-bg-hvr, var(--template-bg-dark-70));
   }
 }