Fixed #1418: set background color to white

src/assets/stylesheets/layout/_base.scss

@@ -36,6 +36,7 @@ $md-toggle__drawer--checked:
 // calculations base on relative ems (rems)
 html {
   min-height: 100%;
+  background-color: $md-color-white;
   // Hack: normally, we would set the base font-size to 62.5%, so we can base
   // all calculations on 10px, but Chromium and Chrome define a minimal font
   // size of 12 if the system language is set to Chinese. For this reason we

src/base.html

@@ -34,7 +34,7 @@
     <!-- Metatags -->
     {% block site_meta %}
       <meta charset="utf-8" />
-      <meta name="viewport" content="width=device-width, initial-scale=1" />
+      <meta name="viewport" content="width=device-width,initial-scale=1" />
 
       <!-- Keep for compatibility, see http://bit.ly/2tMB6ag -->
       <meta http-equiv="x-ua-compatible" content="ie=edge" />