style file
It looks as though Firefox has not download the style file - all webites look old-fashjoned (or simplified or 'basic'). I've upload a screenshot of the BBC website.
Firefox 91.0 macOS Sierra v 10.12.6
Soluzione scelta
Recent release notes say that Firefox automatically enables High Contrast Mode when "Increase Contrast" is checked on MacOS. It can be turned off in FF settings under General -> the Colors... button -> Override the colors specified by the page with your selections above -> Never.
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Soluzione scelta
Recent release notes say that Firefox automatically enables High Contrast Mode when "Increase Contrast" is checked on MacOS. It can be turned off in FF settings under General -> the Colors... button -> Override the colors specified by the page with your selections above -> Never.