I have increased the font size on my Windows computer in Windows to 125%. There are only set sizes. This causes sections of website pages to truncate the message in each section. Is there any way to fix this in Firefox.
I used userChrome.css code to set the font size for the interface, and I set a minimum font size for the content of the web pages. Those sizes are independent of the operating sytem settings for me.
You can use an extension to set a default font size and page zoom on web pages.
Use this extension to adjust the font size for the user interface: