Math expression will be blank if a website use MathJax 3 but disabled AssistiveMml

[CoelacanthusHex]

Our code doesn't detect whether MathML output exists, although it's the default, but it can be disabled or ignored (because it needs to be called explicitly in Non-Component-Based way) by the developer. I have a small change to fix it, just change https://github.com/fred-wang/webextension-native-mathml/blob/efc03f1b6066b27edad421ccb45dfe86455cf922/content-scripts/mathjax-v3.css#L7-L13 to

/* Hide MathJax's own output when MathML existed. */
mjx-container:has(mjx-assistive-mml) mjx-math {
	display: none !important;
}
mjx-container:has(mjx-assistive-mml) svg {
	display: none !important;
}

So the hidden logic will take effect only when MathML output exists. But it has a critical issue: :has only been supported since Chromium 105 (Release date: 2022-09-02) and Firefox 121 (Release date: 2023-12-19)^1. So I post here and expect someone to find a way without :has