The timeline-trigger shorthand defines a timeline-driven trigger that activates and deactivates animations based on ranges. Combines name, source, activation range, and optional active range. Comma-separated for multiple triggers..reveal {
timeline-trigger: --t scroll() entry;
}.reveal {
timeline-trigger: --t view() entry 0% / exit 100%;
animation-trigger: --t;
}noneNo triggers (default).coverRange: starts when the element begins entering the viewport and ends when it fully exits.containRange: active when the element is fully contained within the viewport.entryRange: covers the phase where the element enters the viewport.exitRange: covers the phase where the element exits the viewport.entry-crossingRange: the moment of boundary crossing on entry — when the element's leading edge crosses the viewport edge.exit-crossingRange: the moment of boundary crossing on exit — when the element's leading edge crosses the exit edge.autoThe UA determines the trigger range automatically.normalDefault trigger behavior.CSS Animation Triggers Module Level 1Editor's DraftW3C
