Responsive Checkout Form Resize the browser window to see the effect. When the screen is less than 800px wide, make the two columns stack on top of each other instead of next to each other. Billing Address<i class="fa fa-user"></i> Full Name<i class="fa fa-envelope"></i> Email<i class="fa fa-address-card-o"></i> Address<i class="fa fa-institution"></i> City State Zip Payment Accepted Cards<i class="fa fa-cc-visa" style="color:navy;"></i><i class="fa fa-cc-amex" style="color:blue;"></i><i class="fa fa-cc-mastercard" style="color:red;"></i><i class="fa fa-cc-discover" style="color:orange;"></i> Name on Card Credit card number Exp Month Exp Year CVV Shipping address same as billing Cart <i class="fa fa-shopping-cart"></i><b> 4</b> Product 1 $15 Product 2 $5 Product 3 $8 Product 4 $2 Total <b> $30</b>