I use Pale Moon browser... an offshoot of Firefox. In the preferences it has a tab called 'content'.. and a box called "fonts & colors" with a choice called "default font" and I specify my font... then under that is the choice of "use system colors", which I do NOT choose...

Thus, the page appears to me in regular black type in a font & size of my choosing.

My wife uses Chrome... but I hate it.