Reads the page's root font size and the reader's default font size, and
returns the typography.htmlFontSizehtmlFontSizeFor makes of them.
The default font size is CSS's medium, which nothing exposes directly, so
it is read off a probe element that exists only for the length of this
call. The probe is a child of the root element, so it resolves medium
for the root's own font family and language, and outside <body>, where
host pages and MAIDR's own adapters watch for inserted nodes. It is
display: none, so the read costs a style recalculation and no layout.
Returns number
The value for MUI's typography.htmlFontSize; MUI's default where
there is no document (server-side rendering, a node test)
Reads the page's root font size and the reader's default font size, and returns the
typography.htmlFontSizehtmlFontSizeFor makes of them.The default font size is CSS's
medium, which nothing exposes directly, so it is read off a probe element that exists only for the length of this call. The probe is a child of the root element, so it resolvesmediumfor the root's own font family and language, and outside<body>, where host pages and MAIDR's own adapters watch for inserted nodes. It isdisplay: none, so the read costs a style recalculation and no layout.