bug: Not detecting light mode in tmux

[cboone]

Description
When I've got a light background set in Terminal.app outside of tmux, and no glow style specified (no config file, no flags passed), glow automatically uses the light theme. When I'm inside tmux with the same setup, glow fails to use the light theme. Screenshots below.

Thanks for the great app! (And tools in general.)

Setup
macOS 26.2, Terminal.app, zsh, tmux, LANG=en_US.UTF-8, TERM=tmux-256color

Screenshots