Diagonal boxes
Uses Psuedo elements to fake diagonal borders.
by meetaaronsilber
HTML
<header></header>
<div id="main"></div>
<footer></footer>
CSS
body { background: #444; padding: 0; overflow-x: hidden;}
header, #main, footer { width: 100%; }
header, footer { height: 200px; background: orange;}
#main { height: 300px; position: relative;}
#main:before {
content: '';
width: 0;
height: 0;
position: absolute;
top: -50px;
left: 0px;
border-top: 50px solid transparent;
border-right: 1600px solid #444;
border-bottom: 0px solid transparent;
}