Add Chinese Fonts (xitu#79)

Author: ydfzgyj

site/_css/variables.less

@@ -4,15 +4,15 @@
 @text-color: #202020;
 
 .headline-font(@size: 48px, @color: @text-color) {
-  font-family: 'Rubik', 'Helvetica Neue', Helvetica, Arial, sans-serif;
+  font-family: quote, 'Rubik', 'Helvetica Neue', Helvetica, Arial, 'PingFang SC', 'Hiragino Sans GB', 'Source Han Sans CN', 'Source Han Sans SC', 'Microsoft YaHei', sans-serif;
   font-weight: 300;
   color: @color;
   font-size: @size;
   line-height: @size * 1.4;
 }
 
 .body-font(@size: 18px, @color: @text-color) {
-  font-family: 'Roboto', 'Helvetica Neue', Helvetica, Arial, sans-serif;
+  font-family: quote, 'Roboto', 'Helvetica Neue', Helvetica, Arial, 'PingFang SC', 'Hiragino Sans GB', 'Source Han Sans CN', 'Source Han Sans SC', 'Microsoft YaHei', sans-serif;
   font-weight: 300;
   color: @color;
   font-size: @size;
@@ -26,3 +26,9 @@
   font-size: @size;
   line-height: @size * 17/13;
 }
+
+@font-face {
+  font-family: quote;
+  src: local('Lantinghei SC'), local('SimSun');
+  unicode-range: U+201c, U+201d;
+}