make left sidebar invisible on mobile

static/css/main.css

@@ -499,12 +499,12 @@ input:checked ~ nav{
     display: block;
   }
 
-  .sidebar nav{
-    display: none;
-  }
-  .social {
+  .sidebar nav,
+  .social,
+  .left-sidebar {
     display: none;
   }
+
   h1 {
     font-size: 1.4em;
     margin: 0.3em 0;
@@ -526,7 +526,6 @@ input:checked ~ nav{
   }
 
   .wrapper .sidebar, 
-  .wrapper .left-sidebar,
   .wrapper .content {
       display: block;
       position: static;