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conformance · v146

v146 · named-feature-function-for-css-supports — conformance probe

6 assertions drawn from the spec. Each is a single contract the spec text makes. Pass/fail reflects what this browser executed; blocked means the contract was not run because it needs user mediation, hardware, or another unavailable precondition. Open the page in Chrome stable / canary / Firefox / Safari to compare.

browser: spec: https://drafts.csswg.org/css-conditional-5/#typedef-supports-named-feature-fn chromestatus: #5153932394102784 generated 2026-06-01T08:00:00Z by conformance-author-v1-subagent
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id contract kind verdict detail
css-supports-fn-exists CSS.supports() is the testing API used to evaluate named-feature() conditions. typeof
named-feature-unknown-returns-false An unrecognised feature name passed to named-feature() makes the @supports condition evaluate to false. script
named-feature-parser-recognises-syntax The named-feature() functional notation is a recognised @supports condition (whether or not any specific name is supported). spec ↗ script
named-feature-anchor-position-follows-transforms Named feature 'anchor-position-follows-transforms' is one of the initial registered names exposed by the function. script
named-feature-single-axis-scroll-container Named feature 'single-axis-scroll-container' is recognised by the parser (boolean either way). script
supports-rule-with-named-feature-applies A @supports rule using named-feature() applies styles only when the condition is true, matching standard @supports semantics. script