Diagonal Side div color css js

Question

i have 2 div like this

Answer 1

A single gradient on the parent will do the visual:

html {
  min-height:100%;
  background:linear-gradient(140deg, rgb(153, 180, 211)50%, rgb(217, 181, 150) 50%)
}

example on HTML background sized at 100% viewport's height at the minimum.