Is it possible to customize headers without writing css. As I can see you have only dark and light options. What if I want to change font size, color or backround color only for a specific header?
With the help of Advanced option of Typography, you can set font styles for header without using Custom CSS https://prnt.sc/9iutvPiCJDfn
In order to adjust font styles for specific header, then you can use Custom selector combine with ID of header https://prnt.sc/ddOTTRT-6Jhy and use the Chrome inspector tool or any other browser dev tool to find the HTML structure of the page and classes that all the elements have https://prnt.sc/p2ABhKSH33df assign elements like screenshot https://prnt.sc/4omr6-bPfJQP