<!DOCTYPE html><title>CSS Values and Units Test: rch invalidation</title><linkrel="author"title="Daniil Sakhapov"href="sakhapov@google.com"><linkrel="help"href="https://drafts.csswg.org/css-values/#font-relative-lengths"><scriptsrc="/resources/testharness.js"></script><scriptsrc="/resources/testharnessreport.js"></script><metaname="assert"content="test rch invalidation"><style>@importurl("/fonts/ahem.css");html{font-family:'Ahem';font-size:40px;}body{font-family:monospace;font-size:20px;}div{width:10rch;}</style><html><body><divid="div"></div></body></html><script>setup({single_test:true});letold_width=div.getBoundingClientRect().width;document.documentElement.style.fontFamily="sans-serif";letnew_width=div.getBoundingClientRect().width;assert_not_equals(old_width,new_width,"expect the width of zero of Ahem and sans-serif to be different");done();</script>