adding percentages instead of pixel size to account for mobile phone issue-#33

Author: Ruby Friedman

stylesheet.css

@@ -19,7 +19,7 @@
 
   .navbar ul {
     list-style: none;
-    width: 500px;
+    width: 100%;
     margin: 0 auto;
 
     padding: 0;
@@ -34,7 +34,7 @@
       Style individual list items.
   */
   .navbar li {
-    width: 150 px;
+    width: 25%;
     border: 2px solid rgb(32, 152, 70);
     /* 
           Show the navbar elements next to each other instead of on top of each