Given no requirements other than "one page one function" with a bonus of "works on any computer" I'd use codepen.
Are you sure you want to hide this comment? It will become hidden in your post, but will still be visible via the comment's permalink.
Hide child comments as well
Confirm
For further actions, you may consider blocking this person and/or reporting abuse
We're a place where coders share, stay up-to-date and grow their careers.
Given no requirements other than "one page one function" with a bonus of "works on any computer" I'd use codepen.