<!DOCTYPE html> <!-- Any copyright is dedicated to the Public Domain. http://creativecommons.org/publicdomain/zero/1.0/ --> <!-- This test verifies that we honor percent heights on content inside of a <button> element (resolving the percent against the <button>). (In this testcase, the button has some focus-border/padding, which occupies part of the button's content-box and which we'll have to subtract out from the button's size before using it to resolve percentages sizes.) --> <html> <head> <style> button { width: 80px; border: 0; padding: 0; font: 10px sans-serif; vertical-align: top; color: black; background: gray; -moz-appearance: none; } button::-moz-focus-inner { padding: 6px 0 2px; border: 1px dotted transparent; } div.p80 { height: 80%; background: pink; } div.p100 { height: 100%; background: yellow; } </style> </head> <body> <!--Button has explicit height for us to resolve against: --> <button style="height: 110px"> <div class="p80">abc</div> </button> <button style="height: 110px"> <div class="p100">abc</div> </button> <!--Button is using intrinsic height: --> <button> <div class="p80">abc</div> </button> <button> <div class="p100">abc</div> </button> </body> </html>