Update style

Author: csyonghe

assets/style.scss

@@ -8,11 +8,16 @@ a {
 a:hover {
     text-decoration: underline;
 }
+h2 {
+  font-size:26px;
+}
 h3 {
+    font-size: 22px;
     color: #363636;
 }
 h4 {
     color: #363636;
+    font-size: 20px;
 }
 blockquote {
     background-color: #f2f2f2;