Comment by setopt

If you really only care about syntax highlighting then nearly any code editor will do. Even nano supports it, it’s just disabled by default.

If you want something powerful yet easy to pick up, you might want to look at e.g. Zed (GUI IDE), Sublime Text (GUI editor), or Micro (TUI editor). If you don’t mind a learning curve, Vim/Neovim and Emacs are excellent choices. But there’s a lot of other options out there, like Gedit, Kate, BBEdit, Notepad++, etc. depending on your platform of choice.