Paragraph with a travelling marker

The component is self-contained: one file, zero dependencies, palette in local --vibeui-text-002-* variables. It takes the theme from the environment via light-dark() plus a rule for the .dark class. The paragraph arrives as a single string in the text prop and is split into words right here; the highlighted parts are given as words in highlights rather than indices: the component looks for each phrase as a consecutive chain of words, compared without surrounding punctuation. The reveal is a @keyframes rule per word: translateY(30%) → 0, blur(10px) → 0, opacity 0 → 1 over 550 ms on cubic-bezier(0.16,1,0.3,1), delayed by calc(45 ms * word index). The marker is an absolute backdrop under the word with a negative z-index (the word carries isolation:isolate, otherwise the backdrop would slip behind the paragraph background); on a word inside a phrase it is stretched 0.3em to the right so the space between words is painted too. The marker moves with a transition of scaleX 0.78 → 1 and opacity over 300 ms on a spring written out as linear() points. A client timer runs the phrase queue: it starts once the paragraph has settled and then switches phrases every interval seconds in a loop. Under prefers-reduced-motion the timer never starts and every highlight is shown at once. The word under the marker switches to the accent color (--vibeui-text-002-accent-text, 300 ms), while the backdrop stays lighter than the accent — accent on accent would not read. The lit state arrives inline (opacity, transform and the word color) rather than through a rule on a data attribute: a re-render flips the attributes of the word and its backdrop at once, and such a rule was recomputed one step behind. The data-on and data-edge attributes stay in the markup as a hook for outside styles.