bug fix menu on smaller screens

styles.css

@@ -107,6 +107,8 @@ a.pure-button-primary {
     background: #fcfbfa;
 }
 .pure-menu.pure-menu-fixed {
+    /* Horizontal scroll when overflows */
+    overflow-x: auto;
     /* Fixed menus normally have a border at the bottom. */
     border-bottom: none;
     /* I need a higher z-index here because of the scroll-over effect. */