Adjust the code format and add whitespace

Author: liucht-inspur

docs/css/main.css

@@ -325,7 +325,7 @@ a.anchorjs-link:hover { text-decoration: none; }
   border-bottom-width: 0px;
   margin-top: 0px;
   width: 210px;
-  height:80%;
+  height: 80%;
   float: left;
   position: fixed;
   overflow-y: scroll;