<!DOCTYPE html> <html> <head> <style type="text/css"> #a { height: 20px; background-color: red; margin-bottom: 20px; } #b { height: 20px; background-color: green; margin-bottom: 20px; } #c { height: 20px; background-color: blue; } </style> </head> <body> <div id="a"></div> <div id="b"></div> <div id="c"></div> </body> </html>
