This is the project I made to practice JavaScript basics.
I decided to use a real calculator photo as a base to build my project on, and it was a very interesting challenge to do. Transparent buttons are placed using a grid layout and they change their colour being hovered - that's how I've tried to simulate pressing real buttons.
Clicking the "Off" button disables all buttons except "C/CE" button, which usually works as an "On" button on most calculators.
Buttons M/M-/M+ don't work - anyways, I haven't seen a single person in my life who knows how to use them