Fix form widths (#69)

Author: shaunmaharaj

src/containers/CheckoutAuthPage.less

@@ -36,16 +36,22 @@
     }
   }
 
-  .form-control {
-    display: block;
-    height: 34px;
-    padding: 6px 12px;
-    font-size: 14px;
-    color: #555555;
-    background-color: #ffffff;
-    border: 1px solid #cccccc;
-    border-radius: 4px;
-    box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075);
+  .form-group {
+    @media (min-width: @mobileWidth) {
+      width: 50%;
+    }
+
+    .form-control {
+      display: block;
+      height: 34px;
+      padding: 6px 12px;
+      font-size: 14px;
+      color: #555555;
+      background-color: #ffffff;
+      border: 1px solid #cccccc;
+      border-radius: 4px;
+      box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075);
+    }
   }
 
   .checkout-auth-option-container {