main: fix footer finally now

main/styleguide/source/css/organisms/footer.pcss

@@ -28,9 +28,13 @@
   ul {
     display: flex;
     flex-flow: row wrap;
-    max-height: 320px;
+    max-height: 540px;
     writing-mode: vertical-lr; /* workaround for long-living bug https://stackoverflow.com/a/39102894/7113416 */
 
+    @screen md {
+      max-height: 320px;
+    }
+
     li {
       display: block;
       height: 40px;