[1] document.styleSheetSets - Web API reference | MDN ( ( 版)) <https://developer.mozilla.org/en-US/docs/Web/API/document.styleSheetSets>
[2] [cssom] Remove API for alternative stylesheets · w3c/csswg-drafts@e5353d0 ( 版) <https://github.com/w3c/csswg-drafts/commit/e5353d078e686136fdb28c7de37ffd375cd6d79f>