<!DOCTYPE html> <html> <head> <style> #good { background-color: green; } .abs { position: fixed; margin: 0; padding: 0; top: 25px; left: 25px; width: 50px; height: 50px; background-color: green; } </style> </head> <body> The green square should completely cover the red square. <div class="abs" id="good"></div> </body> </html>