v5.1: Add optional CSS grid (#31813)

scss/_grid.scss

@@ -12,6 +12,40 @@
   }
 }
 
+@mixin make-cssgrid($columns: $grid-columns, $breakpoints: $grid-breakpoints) {
+  @each $breakpoint in map-keys($breakpoints) {
+    $infix: breakpoint-infix($breakpoint, $breakpoints);
+
+    @include media-breakpoint-up($breakpoint, $breakpoints) {
+      @if $columns > 0 {
+        @for $i from 1 through $columns {
+          .g-col#{$infix}-#{$i} {
+            grid-column: auto / span $i;
+          }
+        }
+
+        // `$columns - 1` because offsetting by the width of an entire row isn't possible
+        @for $i from 0 through ($columns - 1) {
+          .g-start#{$infix}-#{$i} {
+            grid-column-start: $i;
+          }
+        }
+      }
+    }
+  }
+}
+
+@if $enable-cssgrid {
+  .grid {
+    display: grid;
+    grid-template-rows: repeat(var(--#{$variable-prefix}rows, 1), 1fr);
+    grid-template-columns: repeat(var(--#{$variable-prefix}columns, #{$grid-columns}), 1fr);
+    gap: var(--#{$variable-prefix}gap, #{$grid-gutter-width});
+
+    @include make-cssgrid();
+  }
+}
+
 
 // Columns
 //

scss/_variables.scss

@@ -221,6 +221,7 @@ $enable-transitions:          true !default;
 $enable-reduced-motion:       true !default;
 $enable-smooth-scroll:        true !default;
 $enable-grid-classes:         true !default;
+$enable-cssgrid:              false !default;
 $enable-button-pointers:      true !default;
 $enable-rfs:                  true !default;
 $enable-validation-icons:     true !default;