|  | <!DOCTYPE html> | 
|  | <meta charset="utf-8"> | 
|  | <title>CSS Selectors: The Specificity-adjustment Pseudo-class: ':where()'</title> | 
|  | <link rel="help" href="https://drafts.csswg.org/selectors/#zero-matches"> | 
|  | <script src="/resources/testharness.js"></script> | 
|  | <script src="/resources/testharnessreport.js"></script> | 
|  | <script src="/css/support/parsing-testcommon.js"></script> | 
|  | <script> | 
|  | test_valid_selector(':where(ul,ol,.list) > [hidden]', | 
|  | ':where(ul, ol, .list) > [hidden]'); | 
|  | test_valid_selector(':where(:hover,:focus)', | 
|  | ':where(:hover, :focus)'); | 
|  | test_valid_selector('a:where(:not(:hover))'); | 
|  |  | 
|  | test_valid_selector(':where(#a)'); | 
|  | test_valid_selector('.a.b ~ :where(.c.d ~ .e.f)'); | 
|  | test_valid_selector('.a.b ~ .c.d:where(span.e + .f, .g.h > .i.j .k)'); | 
|  | </script> |