install stylus extension

if you never knew that you can install an extension to your browser or knew it but never heard of stylus then i will show you.

official site / for chromium browsers / for firefox browsers

once you install, you can click manage button, so it will show it's interface'

here you can click + to create your own style or click the get and share styles on the left bottom to go to the directory domain of the available stylesheets you can easily install and tweak by yourself.