text-decoration-thickness: from-font;
text-underline-offset: .5ex;

.. headed for Chromium 87 🎉
will catch Chromium up with Safari & Firefox! Woot!!
🆕 from-font
look to the font for the font designer’s defined thickness or position, NOT the browser’s default
Intent To Ship: Blink: Intent to Ship: text-decoration-thickness, text-underline-offset and from-font keyword for text-underline-position
https://groups.google.com/a/chromium.org/d/msg/blink-dev/9OzS90KISXI/q5KYyyWBCAAJ