<!DOCTYPE html> <title>@scope - ShadowDOM</title> <link rel="help" href="https://drafts.csswg.org/css-cascade-6/#scope-atrule"> <link rel="help" href="https://github.com/w3c/csswg-drafts/issues/9025"> <script src="/resources/testharness.js"></script> <script src="/resources/testharnessreport.js"></script> <div id=host_plain> <template shadowrootmode=open> <style> @scope (:host) { .a { z-index: 1; } } </style> <div class=a> </div> </template> </div> <script> test(() => { let a = host_plain.shadowRoot.querySelector('.a'); assert_equals(getComputedStyle(a).zIndex, '1'); }, '@scope can match :host'); </script> <div id=host_functional> <template shadowrootmode=open> <style> @scope (:host(div)) { .a { z-index: 1; } } /* Should not match: */ @scope (:host(span)) { .a { z-index: 42; } } </style> <div class=a> </div> </template> </div> <script> test(() => { let a = host_functional.shadowRoot.querySelector('.a'); assert_equals(getComputedStyle(a).zIndex, '1'); }, '@scope can match :host(...)'); </script> <div id=host_scope_subject> <template shadowrootmode=open> <style> @scope (:host) { :scope { z-index: 1; } } </style> <div class=a> </div> </template> </div> <script> test(() => { assert_equals(getComputedStyle(host_scope_subject).zIndex, '1'); }, ':scope matches host via the scoping root'); </script> <div id=host_scope_subject_is> <div class=host> <template shadowrootmode=open> <style> /* Should not match host, nor outside shadow. */ :is(:scope, .a, .host) { z-index: 2; } @scope (:host) { :is(:scope, .a) { z-index: 1; } } </style> <div class=a> </div> </template> </div> <div class=a> </div> </div> <script> test(() => { let host = host_scope_subject_is.querySelector('.host'); assert_equals(getComputedStyle(host).zIndex, '1'); let a = host.shadowRoot.querySelector('.a'); assert_equals(getComputedStyle(a).zIndex, '1'); let a_outside = host_scope_subject_is.querySelector('.a'); assert_equals(getComputedStyle(a_outside).zIndex, 'auto'); }, ':scope within :is() matches host via the scoping root'); </script> <!-- Tentative. https://github.com/w3c/csswg-drafts/issues/9178 --> <div id=implicit_scope_shadow_parent> <div class=host> <template shadowrootmode=open> <style> @scope { /* Matches host */ :scope { z-index: 1; } :scope > .a { z-index: 2; } } </style> <div class=a> </div> </template> </div> </div> <script> test(() => { let host = implicit_scope_shadow_parent.querySelector('.host'); let a = host.shadowRoot.querySelector('.a'); assert_equals(getComputedStyle(host).zIndex, '1'); assert_equals(getComputedStyle(a).zIndex, '2'); }, 'Implicit @scope as direct child of shadow root'); </script> <!-- Tentative. https://github.com/w3c/csswg-drafts/issues/9178 --> <div id=implicit_scope_constructed> <div class=host> <template shadowrootmode=open> <div class=a> </div> </template> </div> </div> <script> test(() => { let host = implicit_scope_constructed.querySelector('.host'); let sheet = new CSSStyleSheet(); sheet.replaceSync(` @scope { :scope { z-index: 1; } :scope .a { z-index: 2; } `); host.shadowRoot.adoptedStyleSheets = [sheet]; let a = host.shadowRoot.querySelector('.a'); assert_equals(getComputedStyle(host).zIndex, '1'); assert_equals(getComputedStyle(a).zIndex, '2'); }, 'Implicit @scope in construted stylesheet'); </script>