The ability to zoom out has been requested a ton of times and is something that makes the game considerably easier both for PvE and PvP.
To do it on firefox just hold ctrl and scroll down.
You go from those 2 states:
Regular

Fullscreen

To those 2 states in 50% zoom:
Regular

Fullscreen

UI elements get really small and text is next to impossible to read.
To do it on firefox just hold ctrl and scroll down.
You go from those 2 states:
Regular

Fullscreen

To those 2 states in 50% zoom:
Regular

Fullscreen

UI elements get really small and text is next to impossible to read.