updated css styles for sizes

public/css/main.css

@@ -217,8 +217,13 @@ table {
     opacity: 0.5;
 }
 
+/* default sizes */
+header, .content, footer {
+    width: 80%;
+    margin: 0px auto;
+}
 
-/* footer icons */
+/* footer */
 footer .link {
     display: inline-block;
     width: 29px;