Fixed grid layouts being pushed out by child content

Ran a quick app run-thorugh in FireFox & Chrome, No secondary affects
immediately noticed but possible this could cause changes elsewhere due
to wide-spread grid item child targeting.

For #3523

resources/sass/_layout.scss

@@ -26,6 +26,9 @@
   display: grid;
   grid-column-gap: $-l;
   grid-row-gap: $-l;
+  > * {
+    min-width: 0;
+  }
   &.half {
     grid-template-columns: 1fr 1fr;
   }