Firefox (on Sway)

Invisible dialogs

Go to about:config, set gfx.webrender.all to true

Bypass blocked websites (only works with firefox-esr-bin 78.6.0-1):

Go to about:preferences, search for dns, enable dns over https
Go to about:config, set network.security.esni.enabled to true
Check status on https://www.cloudflare.com/ssl/encrypted-sni/

Hardware video acceleration (VA-API)

Guide: https://wiki.archlinux.org/index.php/Firefox#Hardware_video_acceleration
Error DRM_IOCTL_I915_GEM_APERTURE failed. Solution:

/etc/mkinitcpio.conf
----------------------
MODULES=(... i915 ...)