Added media queries to css get started demo

devtools-css-get-started/index.html

@@ -54,6 +54,20 @@
       };
     </script>
     <style>
+      @media (min-width: 400px) {
+        body {
+          column-count: 3;
+          column-gap: 1rem;
+        }
+      }
+
+      @media (min-width: 700px) {
+        body {
+          column-count: 4;
+          column-gap: 1rem;
+        }
+      }
+
       /* red orange yellow green blue indigo violet */
       @keyframes rainbow {
         0% {