Reduce bootstrap-grid.css content

scss/_grid.scss

@@ -2,6 +2,12 @@
 //
 // Rows contain your columns.
 
+:root {
+  @each $name, $value in $grid-breakpoints {
+    --#{$prefix}breakpoint-#{$name}: #{$value};
+  }
+}
+
 @if $enable-grid-classes {
   .row {
     @include make-row();