The source code for the website is in the TimidRobot/zehta.me repository. See the README there for additional context and links.
The theme is created using Skeleton (responsive CSS Boilerplate). I call it "Queer Deathstar".
The repository includes the non-minified custom CSS:
Copyright © 2019 Timid Robot Zehta. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.