How to remove classes in a web starting from zero

Hello,

after deleting the content of a web, there are many classes pending to delete, but I don’t see any option to delete them … does anyone know how to do it?

here’s the link
https://preview.webflow.com/preview/clonado-aprender?utm_medium=preview_link&utm_source=designer&utm_content=clonado-aprender&preview=f0fe435d9d3494a3c5f98703a27a9bec&mode=preview