<!DOCTYPE HTML> <html><head> <!-- Any copyright is dedicated to the Public Domain. http://creativecommons.org/publicdomain/zero/1.0/ --> <style> body { width: 450px } input { font-size: 12px } </style> <!-- In a 450px container, the minimum font size at 15em per line is 30px. This means we map 0px-45px into 30px-45px, so 12px gets mapped to 34px. --> </head> <body><input type="checkbox">I have a bike</body> </html>