Frio: Fix aside in mobile view

Aside is fixed to cover page, without the need to scroll back top to see it.

view/theme/frio/css/style.css

@@ -100,6 +100,20 @@ code {
 }
 .help-content-wrapper code {display: inline}
 
+/**
+ * mobile aside
+ */
+@media screen and (max-width: 990px) {
+    aside{
+        position: fixed!important;
+        top: 0!important;
+        background-color: #fff;
+        width: 100%;
+        height: 100%;
+        padding-top: 100px;
+        z-index: 10;
+    }
+}
 /*
 * standard page elements
 */