Updates per MR feedback

- Removes element in favor of class name
- Adjusts to use existing variables

app/assets/stylesheets/pages/builds.scss

@@ -228,18 +228,8 @@
     padding: 16px 0;
   }
 
-  .trigger-variables-table {
-    td {
-      font-size: 12px;
-      line-height: 16px;
-      border: 1px solid #dfdfdf;
-      padding: 4px 6px;
-      width: 50%;
-    }
-  }
-
   .trigger-variables-btn-container {
-    display: flex;
+    @extend .d-flex;
     justify-content: space-between;
   }
 
@@ -260,6 +250,14 @@
     color: $black;
   }
 
+  .trigger-variables-table-cell {
+    font-size: $gl-font-size-small;
+    line-height: $gl-line-height;
+    border: 1px solid $theme-gray-200;
+    padding: $gl-padding-4 6px;
+    width: 50%;
+  }
+
   .badge.badge-pill {
     margin-left: 2px;
   }