<!doctype html> <title>CSS Media Queries Test: ex, ch, and ic from initial font</title> <link rel="help" href="https://drafts.csswg.org/mediaqueries/#units"> <script src="/resources/testharness.js"></script> <script src="/resources/testharnessreport.js"></script> <div id="ex_ref" style="width: 100ex"></div> <div id="ch_ref" style="width: 100ch"></div> <div id="ic_ref" style="width: 100ic"></div> <script> const viewport_width = document.documentElement.offsetWidth; test(() => { const viewport_ex = (viewport_width * 100) / ex_ref.offsetWidth; const ex_query = `(min-width: ${viewport_ex-0.5}ex) and (max-width: ${viewport_ex+0.5}ex)`; assert_true(matchMedia(ex_query).matches); }, "ex unit in media queries should match initial font"); test(() => { const viewport_ch = (viewport_width * 100) / ch_ref.offsetWidth; const ch_query = `(min-width: ${viewport_ch-0.5}ch) and (max-width: ${viewport_ch+0.5}ch)`; assert_true(matchMedia(ch_query).matches); }, "ch unit in media queries should match initial font"); test(() => { const viewport_ic = (viewport_width * 100) / ic_ref.offsetWidth; const ic_query = `(min-width: ${viewport_ic-0.5}ic) and (max-width: ${viewport_ic+0.5}ic)`; assert_true(matchMedia(ic_query).matches); }, "ic unit in media queries should match initial font"); </script>