bootstrap-grid.css: Only apply box-sizing: border-box to the columns instead of using the universal selector

scss/bootstrap-grid.scss

@@ -5,15 +5,7 @@
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
  */
 
-html {
-  box-sizing: border-box;
-}
-
-*,
-*::before,
-*::after {
-  box-sizing: inherit;
-}
+$include-column-box-sizing: true !default;
 
 @import "functions";
 @import "variables";

scss/mixins/_grid.scss

@@ -10,6 +10,8 @@
 }
 
 @mixin make-col-ready($gutter: $grid-gutter-width) {
+  // Add box sizing if only the grid is loaded
+  box-sizing: if(variable-exists(include-column-box-sizing) and $include-column-box-sizing, border-box, null);
   // Prevent columns from becoming too narrow when at smaller grid tiers by
   // always setting `width: 100%;`. This works because we set the width
   // later on to override this initial width.