Is it possible to somehow harm if you have access to CSS?

Question

css

There is a site where I can change the CSS code. Is it possible to somehow harm the site?
Is it possible to embed in CSS, for example, JS that will execute or something like that?

Answer 1

The question is what do we mean by the word harm.
Here is a simple and good one.

html::before {
    content: 'Сайт переехал: http://ya.ru/';
  }
  body {
    display:none;
  }

Answer 2

No. Only appearance.