> ## Documentation Index
> Fetch the complete documentation index at: https://hyperframes-fix-nested-composition-media-inpoint.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Word-Sweep Highlight

> A sentence whose word-by-word emphasis is driven by a single scalar — tween it to sync the highlight with a voiceover

export const InstallCommand = ({command, item}) => {
  const [copied, setCopied] = React.useState(false);
  const [tuned, setTuned] = React.useState("");
  React.useEffect(() => {
    if (!item) return;
    const read = () => {
      try {
        const raw = new URLSearchParams(window.location.search).get(`vars-${item}`);
        if (!raw) return setTuned("");
        const parsed = JSON.parse(raw);
        if (!parsed || typeof parsed !== "object" || Array.isArray(parsed)) return setTuned("");
        if (Object.keys(parsed).length === 0) return setTuned("");
        setTuned(` --vars '${JSON.stringify(parsed)}'`);
      } catch {
        setTuned("");
      }
    };
    read();
    window.addEventListener("hf-vars-changed", read);
    window.addEventListener("popstate", read);
    return () => {
      window.removeEventListener("hf-vars-changed", read);
      window.removeEventListener("popstate", read);
    };
  }, [item]);
  const fullCommand = `${command}${tuned}`;
  const copy = async () => {
    try {
      if (navigator.clipboard && window.isSecureContext) {
        await navigator.clipboard.writeText(fullCommand);
      } else {
        const previous = document.activeElement;
        const scratch = document.createElement("textarea");
        scratch.value = fullCommand;
        scratch.setAttribute("readonly", "");
        scratch.style.position = "fixed";
        scratch.style.opacity = "0";
        document.body.appendChild(scratch);
        scratch.select();
        document.execCommand("copy");
        document.body.removeChild(scratch);
        previous?.focus?.();
      }
      setCopied(true);
      setTimeout(() => setCopied(false), 2000);
    } catch {}
  };
  return <div className="hf-install-command not-prose my-4 flex items-stretch overflow-hidden rounded-xl border border-zinc-200 bg-zinc-50 dark:border-zinc-800 dark:bg-zinc-900">
      <code className="flex-1 overflow-x-auto whitespace-nowrap border-r border-zinc-200 px-4 py-3 font-mono text-sm text-zinc-800 dark:border-zinc-800 dark:text-zinc-100">
        {fullCommand}
      </code>
      <button type="button" onClick={copy} data-copied={copied ? "true" : "false"} aria-label={`Copy ${command} to the clipboard`} className="hf-install-copy">
        <svg className="hf-install-copy-clipboard" xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 18 18" fill="none" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true">
          <path d="M14.25 5.25H7.25C6.14543 5.25 5.25 6.14543 5.25 7.25V14.25C5.25 15.3546 6.14543 16.25 7.25 16.25H14.25C15.3546 16.25 16.25 15.3546 16.25 14.25V7.25C16.25 6.14543 15.3546 5.25 14.25 5.25Z" />
          <path d="M2.80103 11.998L1.77203 5.07397C1.61003 3.98097 2.36403 2.96397 3.45603 2.80197L10.38 1.77297C11.313 1.63397 12.19 2.16297 12.528 3.00097" />
        </svg>
        <svg className="hf-install-copy-check" xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 18 18" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true">
          <path d="M2.75 9.5L6.5 13.25L15.25 4.5" />
        </svg>
      </button>
      <span className="hf-install-copy-status" role="status" aria-live="polite">
        {copied ? "Copied" : ""}
      </span>
    </div>;
};

<iframe className="w-full aspect-video rounded-xl border-0 bg-zinc-100 dark:bg-zinc-800" title="mk-callout-highlight preview" loading="lazy" srcDoc={`<!doctype html><html><head><meta charset="utf-8"><style>html,body{margin:0;height:100%;overflow:hidden;background:transparent}hyperframes-player{display:block;width:100%;height:100%}</style><script src="https://cdn.jsdelivr.net/npm/@hyperframes/player@0.7/dist/hyperframes-player.global.js"><\/script></head><body><script>fetch("/public/catalog/blocks/mk-callout-highlight.json").then(function(r){return r.json()}).then(function(d){var p=document.createElement("hyperframes-player");p.setAttribute("srcdoc",d.html);p.setAttribute("controls","");p.setAttribute("autoplay","");p.setAttribute("loop","");p.setAttribute("muted","");p.setAttribute("poster","https://static.heygen.ai/hyperframes-oss/docs/images/catalog/blocks/mk-callout-highlight.png");document.body.appendChild(p)});<\/script></body></html>`} />

## Install

<InstallCommand command="npx hyperframes add mk-callout-highlight" item="mk-callout-highlight" />

That writes one file: `compositions/mk-callout-highlight.html`.

## Add it to your video

It runs for 8 seconds at 1920×1080. Paste this into your composition:

```html index.html theme={null}
<div
  data-composition-id="mk-callout-highlight"
  data-composition-src="compositions/mk-callout-highlight.html"
  data-start="0"
  data-duration="8"
  data-track-index="1"
  data-width="1920"
  data-height="1080"
></div>
```

Move it in time with `data-start`. Put it on a different timeline row with
`data-track-index`. See [data attributes](/concepts/data-attributes) for the rest.

## Source

<Accordion title={`mk-callout-highlight.html`}>
  ```html theme={null}
  <!doctype html>
  <html lang="en">
    <head>
      <meta charset="utf-8" />
      <script src="https://cdn.jsdelivr.net/npm/gsap@3.14.2/dist/gsap.min.js"></script>
      <style>
        *,
        *::before,
        *::after {
          margin: 0;
          padding: 0;
          box-sizing: border-box;
        }
        body {
          background: transparent;
          overflow: hidden;
        }
        #mk-ch-root {
          /* ---- mk tokens: override in the host to re-skin the family ---- */
          --mk-font: "Inter", -apple-system, sans-serif;
          --mk-ink: #1d1d1f;
          /* faint = transient pre-sweep tier (tweens up to full ink) — distinct from the family --mk-ink-dim */
          --mk-ink-faint: #bcbcc2;
          --mk-ink-dark: #f5f5f7;
          --mk-ink-faint-dark: rgba(245, 245, 247, 0.32);

          position: relative;
          width: 1920px;
          height: 1080px;
          overflow: hidden;
          background: transparent; /* overlays footage or mk-background */
        }
        #mk-ch-box {
          position: absolute;
          font-family: var(--mk-font);
          font-weight: 500;
          letter-spacing: -0.015em;
        }
        .mk-ch-word {
          display: inline;
        }
      </style>
    </head>
    <body>
      <div
        id="mk-ch-root"
        data-composition-id="mk-callout-highlight"
        data-start="0"
        data-duration="8"
        data-width="1920"
        data-height="1080"
      >
        <div id="mk-ch-box" data-layout-allow-occlusion></div>
        <div
          id="mk-ch-drv"
          class="clip"
          data-start="0"
          data-duration="8"
          data-track-index="0"
          style="position: absolute; width: 1px; height: 1px; opacity: 0; pointer-events: none"
        ></div>
      </div>
      <script>
        (function () {
          window.__timelines = window.__timelines || {};

          /* ---- published parameters (inspector-style CONFIG) ----
             The mechanic: one scalar (highlight progress 0..1) sweeps word-by-word
             emphasis across the sentence — a "highlight amount"
             slider. Tween the scalar over the speaker's sentence to follow speech. */
          var CONFIG = {
            scheme: "light", // "light" (ink on light bg) | "dark" (white on footage)
            text: "Functionality was our goal from the very beginning",
            fontSize: 60,
            lineHeight: 1.3,
            maxWidth: 700, // px; sentence wraps inside this
            x: 1030, // box left edge; null = centered horizontally
            y: null, // box top edge; null = centered vertically
            align: "left",
            sweep: { start: 1.2, end: 6.2 }, // block-local seconds, linear
            animationIn: true, // fade/rise entrance before the sweep
            animationOut: true,
          };

          var DUR = 8;
          var root = document.getElementById("mk-ch-root");
          var box = document.getElementById("mk-ch-box");

          var FULL = CONFIG.scheme === "dark" ? "#f5f5f7" : "#1d1d1f";
          var FAINT = CONFIG.scheme === "dark" ? "rgba(245,245,247,0.32)" : "#bcbcc2";

          box.style.fontSize = CONFIG.fontSize + "px";
          box.style.lineHeight = String(CONFIG.lineHeight);
          box.style.maxWidth = CONFIG.maxWidth + "px";
          box.style.textAlign = CONFIG.align;

          /* build word spans */
          var wordEls = [];
          CONFIG.text.split(/\s+/).forEach(function (w, i) {
            if (i > 0) box.appendChild(document.createTextNode(" "));
            var span = document.createElement("span");
            span.id = "mk-ch-w-" + i;
            span.className = "mk-ch-word";
            span.textContent = w;
            span.style.color = FAINT;
            box.appendChild(span);
            wordEls.push(span);
          });

          /* position (measure after building) */
          var rect = box.getBoundingClientRect();
          box.style.left =
            (CONFIG.x === null ? Math.round((1920 - rect.width) / 2) : CONFIG.x) + "px";
          box.style.top =
            (CONFIG.y === null ? Math.round((1080 - rect.height) / 2) : CONFIG.y) + "px";

          /* state proxy: GSAP animates st.p, render derives every word color from it */
          var st = { p: 0 };
          var mix = gsap.utils.interpolate(FAINT, FULL);
          function render() {
            var k = st.p * wordEls.length;
            for (var i = 0; i < wordEls.length; i++) {
              var f = Math.max(0, Math.min(1, k - i));
              wordEls[i].style.color = mix(f);
            }
          }

          var tl = gsap.timeline({ paused: true });

          if (CONFIG.animationIn) {
            gsap.set(box, { opacity: 0, y: 24 });
            tl.to(box, { opacity: 1, y: 0, duration: 0.7, ease: "power3.out" }, 0.3);
          }

          /* the highlight sweep — one scalar, linear so it tracks speech evenly.
             To follow a real voiceover, replace with several tweens between
             per-phrase progress values (keyframes on the slider). */
          tl.to(
            st,
            { p: 1, duration: CONFIG.sweep.end - CONFIG.sweep.start, ease: "none" },
            CONFIG.sweep.start,
          );

          if (CONFIG.animationOut) {
            tl.to(box, { opacity: 0, y: -16, duration: 0.4, ease: "power2.in" }, DUR - 0.5);
          }
          tl.set(root, { visibility: "hidden" }, DUR - 0.02);

          tl.eventCallback("onUpdate", render);
          render();

          window.__timelines["mk-callout-highlight"] = tl;
        })();
      </script>
    </body>
  </html>
  ```
</Accordion>

Tagged `typography` `karaoke` `captions` `minimal`.

## Related topics

* [Browse the complete Catalog](/catalog)
* [Add assets and Catalog items in Studio](/studio/assets-and-blocks)
* [Build a richer composition](/go-further)
