For Mac/Windows: https://sr.ht/~julienxx/Castor/
The following is for Ubuntu Linux:
$ sudo -i
$ cd /opt
$ git clone https://git.sr.ht/~julienxx/castor
$ cd castor
$ apt install build-essential rustc cargo libgtk-3-dev libgdk-pixbuf2.0-dev libssl-dev
$ make && make install
$ exit
It's installed so, open Castor...
Settings are storged in /home/USERNAME/.config/castor/settings.toml
$ nano ~/.config/castor/settings.toml
[general]
start_url = ""
max_width = 200
[colors]
h1 = "red"
h2 = "#0099ff"
h3 = "#00ffff"
list = "red"
text = "#c7ff96"
background = "#141a0f"
[colors.quote]
foreground="#e4e4e4"
background="grey"
[characters]
h1 = ". "
h2 = ".. "
h3 = "... "
list = "💡 "
[fonts]
[fonts.finger]
family = "monospace"
size = 12
[fonts.gemini.text]
family = "serif"
size = 13
[fonts.gemini.h1]
family = "sans"
size = 16
style = "normal"
[fonts.gemini.h2]
family = "monospace"
size = 14
style = "italic"
[fonts.gemini.h3]
family = "monospace"
size = 13
[fonts.gemini.list]
family = "sans"
size = 12
style = "oblique"
[fonts.gemini.quote]
family = "sans"
size = 11
style = "italic"
[fonts.gopher]
family = "monospace"
size = 12