Example update

Say to to see the reflow effect.

working-examples/css-grid/index.html

@@ -177,7 +177,7 @@
 
     <main role="main" class="grid-item">        
       <h1>Using media queries and grid CSS to reflow columns</h1>
-      <p>The objective of this technique is to be able to present content without introducing horizontal scroll bars by using layout techniques that adapt to the available horizontal space.</p>
+      <p>The objective of this technique is to be able to present content without introducing horizontal scroll bars by using layout techniques that adapt to the available horizontal space. To view the effect use the zoom feature, or change the window width of your browser. The remaining text is Latin filler text not intended to convey information.</p>
       <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nunc porttitor lorem vitae quam aliquam, vel vulputate dolor ultricies. Sed sed nunc ipsum. Aliquam rhoncus risus pellentesque, faucibus nunc sodales, laoreet risus. Nulla interdum purus at facilisis porta.</p>
       <div class="subgrid">
         <div class="subgrid-item">