MacOS Monterey Safari Dark от Eason

<a href="https://addons.mozilla.org/firefox/addon/adaptive-tab-bar-colour/">Adaptive Tab Bar Colour</a> can make your Firefox look closer to macOS Safari by changing the tab bar colour according to the web content.

All the colors are dirctly picked from MacOS Safari in dark mode using colour meter.

To make Firefox looks closer to Safari, you can customise the toolbar to centralise the search bar.