Changes

/* override mapped width and height attributes */ width: 100% !important; height: 100% !important;

/* In If there is a full-screen mode, if the root element itself that is not full-screen the root then

:root:-full-screen-ancestor { overflow: hidden; } :full-screen-ancestor { /* Ancestors of a full-screen element should not induce stacking contexts that would prevent the full-screen element from being on top. */ z-index:auto; /* Ancestors of a full-screen element should not be partially transparent, since that would apply to the full-screen element and make the page visible behind it. It would also create a pseudo-stacking-context that would let content draw on top of the full-screen element. */ opacity:1; /* Ancestors of a full-screen element should not apply SVG masking, clipping, or filtering, since that would affect the full-screen element and create a pseudo- stacking context. */ mask:none; clip:none; filter:none;

Note that it is possible for a document For these to position content over an element with the :full-screen pseudo-classbe effective, for example if the :fullwe really want their to be higher precedence than non-screen element is in important author rules. So we might need to add a container with z-index not 'autonew precedence level for UA style rules that's between "author" and "author important".