Calculator App (CSS Grid, Custom Properties, SASS, JS, jQuery, ReExps)

This was a really tricky challenge for me but I learned so much. Do you think the page is good for accessibility? I adjusted the design of the toggle to help people with large fingers select the color themes. I wanted to create navigation on the calculator buttons with the arrow keys, however the solution I came up with didn't really work; for some reason it made the page really slow.