Add a outline hack for scrolling issue

Author: muan

assets/css/content.css

@@ -321,3 +321,16 @@ pre code {
   border-top-right-radius: 3px;
   transform: rotate(-45deg);
 }
+
+/* Hacks --------------------- */
+
+/* Fixes horizontal scrolling in code blocks on OS X El Cap (10.11.3), retina screen
+ *
+ * By adding an invisible outline property, it will force a repaint
+ * which enables the scrolling.
+ */
+
+.hljs:hover,
+.hljs:active {
+  outline: 1px solid transparent;
+}