This is not posted as a separate answer but that's an obvious answer.

There is a CSS repeating-linear-gradient() rule

For example, background: repeating-linear-gradient(45deg, #e0e0e0, #e0e0e0 20px, #eaeaea 21px, #eaeaea 40px);

https://developer.mozilla.org/en-US/docs/Web/CSS/gradient/repeating-linear-gradient