To be fair, they do explicitly say "build a minimal, terminal-inspired email client" and then "Email client can either be in the terminal (i.e. a TUI) or a web

To be fair, they do explicitly say "build a minimal, terminal-inspired email client" and then "Email client can either be in the terminal (i.e. a TUI) or a web app" below, so even if it's a web app, they expected it to be terminal inspired, especially from the next paragraph in "Inspiration": > Your implementation should take inspiration from existing terminal email tools like aerc, mutt, or even something like himalaya.