CSS High precision measurements, inputs, simple form

Question

I am firts know.

Can someone modify this example for me, but that the measurements are totally exact in horizontal? (and auto ajust size screen offcourse).

Code: https://www.w3schools.com/code/tryit.asp?filename=GQ2J7FETCPBY

Very thanks.

Answer 1

add css

* {
    box-sizing: border-box;
}