Twine2 is a great tool for beginners to make games, but there aren't customization options out of the box, and the way to use CSS is not well documented. This template is a well-commented basic reset that allows you to make your game look unique without knowing too much about CSS.
Why do you think that https://github.com/ChapelR/harlowe-macro-api is a good alternative to twine-css-template