Style: fix padding and color on the demo reference page (#1057)

* style: remove large space at the top of the reference page

* style: fix sidebar color for reference page

example/reference/index.html

@@ -176,6 +176,10 @@
     #loading-screen.is-loaded {
       display: none;
     }
+
+    .hub-container {
+      display: flex;
+    }
   </style>
 </head>
 
@@ -230,20 +234,17 @@ <h1 id="header-logo">Swagger Preview</h1>
             position: initial;
             padding-bottom: 0px;
           }
+          #hub-sidebar-content a.text-overflow {
+            background: #fff!important;
+          }
           section#hub-content {
             border-left: 1px solid #ddd;
-            margin-left: 246px;
             padding-left: 0px;
             width: unset;
           }
           section#hub-content.with-errors {
             border-left: none;
           }
-          @media (max-width: 768px) {
-            section#hub-content {
-              margin-left: 0 !important;
-            }
-          }
         </style>
         <div id="hub-sidebar-parent" class="hub-sidebar-sticky">
           <nav id="hub-sidebar">