Creating a diagonal line/section/border with CSS

Question

I am trying to create a diagonal line on a webpage, to act as a section/section break. This is essentially a split colour section. I cant use an image as if the page gets en

Answer 1

Use a linear gradient

div {
  height: 90px;
  background-image: linear-gradient(to bottom right, yellow, yellow 50%, black 50%, black);
}