<!DOCTYPE HTML> <html> <head> <meta charset="utf-8"> <title>CSS Reftest Test</title> <link rel="author" title="Kyle Zentner" href="mailto:zentner.kyle@gmail.com"> <style> body { margin: 0; } #a { background: blue; margin: 10px; width: 50px; height: 50px; } #b { width: 50px; height: 40px; background: green; } #b-padding { height: 10px; } </style> </head> <body> <div id="a"> <div id="b-padding"></div> <div id="b"></div> </div> </body> </html>