@namespaceThe @namespace CSS rule sets a default namespace or namespace prefix. Namespace prefixes allow CSS selectors to distinguish elements with the same name but different document types, such as the HTML <a> element and the SVG <a> element.cssCSSwidely2015-07-292018-01-29https://drafts.csswg.org/css-namespaces-3/#declarationcss-namespaceshttps://developer.mozilla.org/docs/Web/API/CSSNamespaceRuleapi.CSSNamespaceRuleapi.CSSNamespaceRule.namespaceURIapi.CSSNamespaceRule.prefixcss.at-rules.namespacecss.selectors.namespacehttps://nowyoucanuse.com/features--namespace.html