Hi,
Have a look at my calculator: https://zelite.github.io/JavaScript-Calculator/
One thing I still did not figure out, is how to make the text disappear on the left when the box overflows? When I fill up the entry field, instead of keep pushing the numbers to the left side, it stops and the numbers disappear to the right side.
And now I find out that the key codes captured by the keydown event are different from Chrome to Microsoft Edge =/ must refactor the keyboard handling code…