Calculator App (HTML, CSS, JS, JQUERY)

Hello!

This is my first intermediate challenge. I'm satisfied 'cause it's perhaps a bit difficult for my current level. I left a comment in the last line of the "script.js" file about what I couldn't manage: not having split operators and operands, the user can select multiple operators in a row (e.g. "++", "+", "/", etc.). I think I need to totally change my structure to fix it, but if anyone knows how to do it without disrupting the whole code (:D), I'd be happy to read your advice!

Thank you!