<!DOCTYPE html> <html class=reftest-wait> <title>::backdrop for a fullscreen iframe element</title> <link rel=match href="backdrop-iframe-ref.html"> <link rel=help href="https://github.com/w3c/csswg-drafts/issues/6939"> <script src="/resources/testdriver.js"></script> <script src="/resources/testdriver-vendor.js"></script> <style> iframe::backdrop { background: green; } </style> <iframe></iframe> <script> document.addEventListener('fullscreenchange', () => { document.documentElement.classList.remove('reftest-wait'); }); test_driver.bless('fullscreen', () => { document.querySelector('iframe').requestFullscreen(); }); </script>