<!doctype html> <html> <head> <style> button { position:relative; padding:0; background:green; width: 200px; height: 100px; border:none; text-align: left; font: 12px serif; -moz-appearance: none; border-radius: 0 !important; } button span { display:block; position:absolute; right:0; top:0; width:10px; height:100%; background:red; } </style> </head> <body> <button> <span></span> </button> </body> </html>