> ## 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.

# Whiteboard Ink

> A whiteboard sketch draws one measured stroke at a time while a pen nib follows the active tip. Preset sketches (bulb, flow, rocket) or your own multi-stroke SVG paths via the strokes slot; a path marked data-ink=accent rides the accent token.

export const VariablesExplorer = ({previewSrc, compositionId, compositionSrc, variables, children}) => {
  const SHIKI = {
    punct: {
      color: "rgb(31, 35, 40)",
      "--shiki-dark": "#808080"
    },
    tag: {
      color: "rgb(17, 99, 41)",
      "--shiki-dark": "#569CD6"
    },
    attr: {
      color: "rgb(5, 80, 174)",
      "--shiki-dark": "#9CDCFE"
    },
    equals: {
      color: "rgb(31, 35, 40)",
      "--shiki-dark": "#D4D4D4"
    },
    value: {
      color: "rgb(10, 48, 105)",
      "--shiki-dark": "#CE9178"
    }
  };
  const CSS = `
.hf-ve {
  --ve-fg: #18181b;
  --ve-muted: #71717a;
  --ve-line: #e4e4e7;
  --ve-surface: #ffffff;
  --ve-sunken: #fafafa;
  --ve-hover: #f4f4f5;
  --ve-on-bg: #18181b;
  --ve-on-fg: #ffffff;
  --ve-ring: rgba(24, 24, 27, 0.14);
  --ve-danger: #b42318;
}
:where(html.dark) .hf-ve {
  --ve-fg: #f4f4f5;
  --ve-muted: #a1a1aa;
  --ve-line: #27272a;
  --ve-surface: #18181b;
  --ve-sunken: #131316;
  --ve-hover: #27272a;
  --ve-on-bg: #f4f4f5;
  --ve-on-fg: #18181b;
  --ve-ring: rgba(244, 244, 245, 0.2);
  --ve-danger: #ff9d95;
}

.hf-ve-tabs {
  display: inline-flex;
  gap: 2px;
  padding: 3px;
  border: 1px solid var(--ve-line);
  border-radius: 9999px;
  background: var(--ve-sunken);
}
.hf-ve-tab {
  padding: 4px 12px;
  border-radius: 9999px;
  font-size: 12px;
  font-weight: 500;
  color: var(--ve-muted);
  background: transparent;
}
.hf-ve-tab[data-on="true"] {
  color: var(--ve-fg);
  background: var(--ve-surface);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08);
}
.hf-ve-tab:hover:not([data-on="true"]) { color: var(--ve-fg); }

/* Not a grid. A grid row is as tall as its tallest cell, so a five-line snippet
   sat in the preview's 16:9 box with 300px of dead area under it. The inactive
   pane is taken out of flow instead — and stretches left/right rather than to
   inset 0, so the iframe keeps its own height. An iframe resized on every tab
   switch reflows the composition running inside it. */
.hf-ve-frame { position: relative; }
.hf-ve-cell { min-width: 0; }
.hf-ve-cell[data-on="false"] {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  visibility: hidden;
  pointer-events: none;
}
.hf-ve-preview {
  overflow: hidden;
  border: 1px solid var(--ve-line);
  border-radius: 12px;
}
/* CodeBlock carries the page margins (mt-5 mb-8) that separate it from prose,
   which is dead space inside a tab. Element plus two classes out-specifies a
   Tailwind utility without !important. */
.hf-ve-cell > div.code-block { margin: 0; }
/* The snippet wraps; the source does not.
   A value the reader has to read in full should not hide half of itself off the
   right edge, so the snippet pane wraps — what \`\`\`html wrap does for a fence.
   The width reset is the half that matters: the block's own <code> is sized to
   max-content, and content that never meets an edge never wraps.
   Source is left to scroll sideways like every other code block on the site.
   Wrapping it breaks its indentation, and a comment paragraph re-flowed to a
   narrow column reads worse than one the reader can scroll. */
.hf-ve-snippet .shiki,
.hf-ve-snippet .shiki code {
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}
/* A composition source runs to several hundred lines, and an un-capped tab
   pushes the Customize panel off the screen. The cap goes on the scroll box
   rather than the block, so the filename and its copy button stay put; and it
   is a max-height, so a short source still hugs its own content and the dead
   area under it stays gone. */
.hf-ve-cell .code-block pre {
  max-height: 460px;
  overflow: auto;
}
/* Four classes deep because the rule being answered is three
   (\`html:not(.dark) .codeblock-light pre.shiki code\`), and a shorter selector
   silently loses to it. */
.hf-ve .hf-ve-snippet .code-block pre.shiki code {
  width: auto;
  min-width: 0;
}

.hf-ve-panel {
  margin-top: 12px;
  border: 1px solid var(--ve-line);
  border-radius: 12px;
}
.hf-ve-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 16px;
  border-bottom: 1px solid var(--ve-line);
}
.hf-ve-title {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ve-muted);
}
.hf-ve-grid {
  display: grid;
  gap: 16px 28px;
  padding: 16px;
}
@media (min-width: 640px) {
  .hf-ve-grid { grid-template-columns: 1fr 1fr; }
}
.hf-ve-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 6px;
}
.hf-ve-label { font-size: 14px; font-weight: 500; color: var(--ve-fg); }
.hf-ve-value {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 12px;
  font-variant-numeric: tabular-nums;
  color: var(--ve-muted);
}
.hf-ve-desc {
  margin: 6px 0 0;
  font-size: 12px;
  line-height: 1.45;
  color: var(--ve-muted);
}

.hf-ve-btn {
  padding: 4px 10px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-size: 12px;
  font-weight: 500;
  color: var(--ve-muted);
  background: transparent;
}
.hf-ve-btn:hover:not(:disabled) { color: var(--ve-fg); background: var(--ve-hover); }
.hf-ve-btn:disabled { opacity: 0.4; cursor: default; }

.hf-ve-field {
  width: 100%;
  height: 36px;
  padding: 0 12px;
  border: 1px solid var(--ve-line);
  border-radius: 8px;
  font-size: 14px;
  line-height: 1.4;
  color: var(--ve-fg);
  background: var(--ve-surface);
}
.hf-ve-field::placeholder { color: var(--ve-muted); }
.hf-ve-mono { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 13px; }

/* Focus, once, for every control here. A ring outside the border rather than a
   border colour alone: the border already carries the resting state, so
   recolouring it is a change a reader can miss. Nothing shifts, because the
   ring is a shadow. :focus-visible, so a pointer click does not light it up. */
.hf-ve-field:focus-visible,
.hf-ve-seg-btn:focus-visible,
.hf-ve-tab:focus-visible,
.hf-ve-btn:focus-visible,
.hf-ve-switch:focus-visible,
.hf-ve-swatch:focus-visible {
  outline: none;
  border-color: var(--ve-on-bg);
  box-shadow: 0 0 0 3px var(--ve-ring);
}
/* A range is a track, and ringing the track rings a pill the width of the
   panel. The thumb is the part that has focus, so the thumb is what says so. */
.hf-ve-range:focus-visible { outline: none; }
.hf-ve-range:focus-visible::-webkit-slider-thumb { box-shadow: 0 0 0 4px var(--ve-ring); }
.hf-ve-range:focus-visible::-moz-range-thumb { box-shadow: 0 0 0 4px var(--ve-ring); }
/* Safari still fires :focus for a click on a button, so the pair is kept. */
.hf-ve-field:focus { outline: none; border-color: var(--ve-on-bg); }

/* The enum branch above sends anything past four options here. No shipped item
   does today (every enum in the registry has two to four), so this is styled to
   the point of not looking foreign and no further — the chevron is one neutral
   grey rather than a per-theme pair, because a data URI cannot read a token. */
.hf-ve-select {
  appearance: none;
  -webkit-appearance: none;
  padding-right: 34px;
  background-image: url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='none' stroke='%2389898f' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m4 6 4 4 4-4'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
  cursor: pointer;
}

.hf-ve-seg {
  display: flex;
  padding: 2px;
  border: 1px solid var(--ve-line);
  border-radius: 8px;
}
.hf-ve-seg-btn {
  flex: 1;
  padding: 4px 8px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 500;
  color: var(--ve-muted);
  background: transparent;
}
.hf-ve-seg-btn:hover:not([data-on="true"]) { color: var(--ve-fg); background: var(--ve-hover); }
.hf-ve-seg-btn[data-on="true"] { color: var(--ve-on-fg); background: var(--ve-on-bg); }

/* A range, rebuilt. \`accent-color\` alone leaves the platform's hairline track,
   which reads as an unstyled browser part next to everything else here. Each
   engine names its parts differently and shares none of them, so the same
   track and thumb are written twice; a selector either engine cannot parse
   drops the whole rule, which is why they are never grouped. */
.hf-ve-range {
  width: 100%;
  height: 20px;
  appearance: none;
  -webkit-appearance: none;
  border: 0;
  border-radius: 9999px;
  background: transparent;
  cursor: pointer;
}
/* --ve-fill is set per render: painting progress on a native track means a
   two-stop gradient, and only the component knows where the value sits. */
.hf-ve-range::-webkit-slider-runnable-track {
  height: 6px;
  border-radius: 9999px;
  background: linear-gradient(
    to right,
    var(--ve-on-bg) var(--ve-fill, 0%),
    var(--ve-line) var(--ve-fill, 0%)
  );
}
.hf-ve-range::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  margin-top: -5px;
  border: 2px solid var(--ve-on-bg);
  border-radius: 9999px;
  background: var(--ve-surface);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.14);
}
.hf-ve-range::-moz-range-track { height: 6px; border-radius: 9999px; background: var(--ve-line); }
.hf-ve-range::-moz-range-progress { height: 6px; border-radius: 9999px; background: var(--ve-on-bg); }
.hf-ve-range::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border: 2px solid var(--ve-on-bg);
  border-radius: 9999px;
  background: var(--ve-surface);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.14);
}
/* Hover reads on the part being aimed at rather than on the whole strip: a
   track that darkens under the pointer says "click me and the thumb comes
   here", which is what a native range actually does. */
.hf-ve-range:hover::-webkit-slider-thumb { border-color: var(--ve-fg); }
.hf-ve-range:hover::-moz-range-thumb { border-color: var(--ve-fg); }

/* The number control, and the three things it used to leave unsaid.
 *
 * It could not say where the range ends, so a reader dragging \`stroke_width\`
 * had no idea whether 12 was nearly nothing or nearly everything: the ends now
 * carry min and max.
 *
 * It could not say where the author left the knob, which is the one reference
 * point a panel built around deviating from the author's choice needs: a mark
 * on the track is the default, and a double click puts the value back on it.
 *
 * And it printed the value in the label row, a fixed distance from a thumb that
 * moves, so reading a drag meant looking in two places at once. The value rides
 * the thumb instead.
 *
 * Still a real <input type="range">. Every custom slider on the web reimplements
 * keyboard stepping, touch, and the screen-reader contract, and most of them do
 * one of the three badly; none of what is added here needed the element
 * replaced. Nothing moves that a finger is not moving: the value tracks the
 * pointer because it is the pointer's own readout, and the only transition is
 * the colour one every other control here shares. */
.hf-ve-slider {
  display: grid;
  gap: 1px;
}
.hf-ve-ruler {
  position: relative;
  height: 17px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 11px;
  font-variant-numeric: tabular-nums;
  line-height: 17px;
  color: var(--ve-muted);
}
.hf-ve-bound {
  position: absolute;
  top: 0;
}
.hf-ve-bound[data-end="min"] { left: 0; }
.hf-ve-bound[data-end="max"] { right: 0; }
/* An end steps aside rather than being overprinted by the value arriving on
   top of it. Visibility, not opacity: there is no fade here, the label is
   either the thing being read or it is out of the way. */
.hf-ve-ruler[data-near="min"] .hf-ve-bound[data-end="min"],
.hf-ve-ruler[data-near="max"] .hf-ve-bound[data-end="max"] {
  visibility: hidden;
}
/* translateX is centring, not motion: the readout is as wide as its own digits
   and has to hang half of that either side of the thumb. */
.hf-ve-readout {
  position: absolute;
  top: 0;
  left: calc(var(--ve-fill, 0%) + var(--ve-fill-nudge, 0px));
  transform: translateX(-50%);
  color: var(--ve-fg);
  font-weight: 600;
  white-space: nowrap;
}
.hf-ve-track {
  position: relative;
  display: block;
}
.hf-ve-range { display: block; }
.hf-ve-default {
  position: absolute;
  top: 5px;
  left: calc(var(--ve-default, 50%) + var(--ve-default-nudge, 0px));
  width: 2px;
  height: 10px;
  margin-left: -1px;
  border-radius: 1px;
  background: var(--ve-muted);
  pointer-events: none;
}

/* A switch, for the boolean type. It used to fall through to the text input at
   the end of control(), which asked the reader to type the word "true". */
.hf-ve-switch {
  display: inline-flex;
  align-items: center;
  width: 40px;
  height: 24px;
  padding: 2px;
  border: 1px solid var(--ve-line);
  border-radius: 9999px;
  background: var(--ve-sunken);
  cursor: pointer;
}
.hf-ve-switch[data-on="true"] { border-color: var(--ve-on-bg); background: var(--ve-on-bg); }
.hf-ve-switch-dot {
  width: 18px;
  height: 18px;
  border-radius: 9999px;
  background: var(--ve-surface);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.18);
}
.hf-ve-switch[data-on="true"] .hf-ve-switch-dot {
  background: var(--ve-on-fg);
  transform: translateX(16px);
}

/* The SVG import control: the same text field, with a way to fill it.
 *
 * The whole block is the drop target, not just the field, so a file let go over
 * the button lands too. It says so by taking the same border colour a focused
 * field takes, which is the one feedback channel this panel has left.
 *
 * A bare <input type="file"> is unlabelled, unstyleable and reads as "No file
 * chosen" next to controls that carry their own value, so the real input is
 * taken out of the layout and the tab order and a button in front of it is what
 * a reader sees and what a keyboard reaches. Hidden with size and opacity
 * rather than display:none, because an input that is not rendered at all is one
 * some browsers decline to open a picker for. */
.hf-ve-drop {
  display: grid;
  gap: 8px;
}
.hf-ve-drop[data-over="true"] .hf-ve-dropzone {
  border-color: var(--ve-on-bg);
  border-style: solid;
}

/* The import is the action almost everyone wants: a reader arrives with a
   shape, not with path data. A dashed target reads as "put a file here" on
   sight, where a button beneath a field of coordinates read as an afterthought
   to the coordinates. */
.hf-ve-dropzone {
  display: grid;
  justify-items: center;
  gap: 6px;
  padding: 18px 12px;
  border: 1px dashed var(--ve-line);
  border-radius: 10px;
  background: var(--ve-surface);
  text-align: center;
}
.hf-ve-dropzone .hf-ve-btn {
  padding: 7px 16px;
  font-size: 13px;
  color: var(--ve-fg);
  border-color: var(--ve-line);
  background: var(--ve-bg);
}
.hf-ve-dropzone .hf-ve-btn:hover:not(:disabled) { background: var(--ve-hover); }

/* Path data stays reachable, but a reader has to ask for it. A native details
   element rather than our own toggle, so it opens with the keyboard and is
   announced as expandable without any wiring. */
.hf-ve-advanced > summary {
  font-size: 12px;
  color: var(--ve-muted);
  cursor: pointer;
  list-style: none;
  padding: 2px 0;
}
.hf-ve-advanced > summary::-webkit-details-marker { display: none; }
.hf-ve-advanced > summary::before { content: "▸ "; }
.hf-ve-advanced[open] > summary::before { content: "▾ "; }
.hf-ve-advanced > summary:hover { color: var(--ve-fg); }
.hf-ve-advanced .hf-ve-field { margin-top: 6px; }
.hf-ve-file {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}
.hf-ve-note {
  margin: 0;
  min-width: 0;
  font-size: 12px;
  line-height: 1.4;
  color: var(--ve-muted);
}
.hf-ve-note[data-tone="error"] { color: var(--ve-danger); }
.hf-ve-note[data-tone="ok"] { color: var(--ve-fg); }

.hf-ve-swatch {
  width: 40px;
  height: 32px;
  flex-shrink: 0;
  padding: 2px;
  border: 1px solid var(--ve-line);
  border-radius: 8px;
  background: var(--ve-surface);
  cursor: pointer;
}

/* Nothing here moves.
 *
 * A press-down scale on every button and field, a scale-in on the tab panes, a
 * springing switch knob and a growing slider thumb were all flourish: the
 * control had already told you what it did by changing colour, and the motion
 * was a second, slower answer to a question already settled. What is left is
 * one colour transition, short enough to read as immediate and long enough not
 * to flicker. A control here may change colour; it does not move.
 *
 * Which is also why there is no prefers-reduced-motion block any more. There is
 * no motion left to reduce. */
.hf-ve-tint {
  transition:
    background-color 100ms ease,
    border-color 100ms ease,
    color 100ms ease;
}
`;
  const isSvgPathData = value => typeof value === "string" && (/^\s*[Mm]\s*-?[\d.]/).test(value);
  const parsePathData = d => {
    const source = String(d);
    const arity = {
      M: 2,
      L: 2,
      H: 1,
      V: 1,
      C: 6,
      S: 4,
      Q: 4,
      T: 2,
      A: 7,
      Z: 0
    };
    const commands = [];
    let at = 0;
    let code = "";
    const separator = () => {
      while (at < source.length && (/[\s,]/).test(source[at])) at += 1;
    };
    const digits = () => {
      while (at < source.length && source[at] >= "0" && source[at] <= "9") at += 1;
    };
    const number = () => {
      separator();
      const start = at;
      if (source[at] === "+" || source[at] === "-") at += 1;
      digits();
      if (source[at] === ".") {
        at += 1;
        digits();
      }
      if (source[at] === "e" || source[at] === "E") {
        at += 1;
        if (source[at] === "+" || source[at] === "-") at += 1;
        digits();
      }
      const text = source.slice(start, at);
      const value = Number(text);
      if (text === "" || !Number.isFinite(value)) {
        throw new Error(`expected a number at character ${start + 1}`);
      }
      return value;
    };
    const flag = () => {
      separator();
      const character = source[at];
      if (character !== "0" && character !== "1") {
        throw new Error(`expected an arc flag at character ${at + 1}`);
      }
      at += 1;
      return Number(character);
    };
    separator();
    while (at < source.length) {
      const character = source[at];
      if ((/[a-zA-Z]/).test(character)) {
        if (arity[character.toUpperCase()] === undefined) {
          throw new Error(`unknown command "${character}"`);
        }
        code = character;
        at += 1;
      } else if (code === "") {
        throw new Error("path data must open with a command");
      } else if (code === "M" || code === "m") {
        code = code === "M" ? "L" : "l";
      } else if (code === "Z" || code === "z") {
        throw new Error(`expected a command at character ${at + 1}`);
      }
      const letter = code.toUpperCase();
      const args = [];
      if (letter === "A") {
        args.push(number(), number(), number(), flag(), flag(), number(), number());
      } else {
        for (let taken = 0; taken < arity[letter]; taken += 1) args.push(number());
      }
      commands.push({
        code,
        args
      });
      separator();
    }
    if (commands.length === 0) throw new Error("path data is empty");
    return commands;
  };
  const normalisePathData = commands => {
    const out = [];
    let x = 0;
    let y = 0;
    let startX = 0;
    let startY = 0;
    let cubicControl = null;
    let quadraticControl = null;
    for (const {code, args} of commands) {
      const letter = code.toUpperCase();
      const relative = code !== letter;
      const dx = relative ? x : 0;
      const dy = relative ? y : 0;
      const pairs = values => {
        const mapped = [];
        for (let index = 0; index + 1 < values.length; index += 2) {
          mapped.push(values[index] + dx, values[index + 1] + dy);
        }
        return mapped;
      };
      let nextCubic = null;
      let nextQuadratic = null;
      if (letter === "M") {
        const [px, py] = pairs(args);
        out.push({
          code: "M",
          args: [px, py]
        });
        x = px;
        y = py;
        startX = px;
        startY = py;
      } else if (letter === "L") {
        const [px, py] = pairs(args);
        out.push({
          code: "L",
          args: [px, py]
        });
        x = px;
        y = py;
      } else if (letter === "H") {
        x = args[0] + dx;
        out.push({
          code: "L",
          args: [x, y]
        });
      } else if (letter === "V") {
        y = args[0] + dy;
        out.push({
          code: "L",
          args: [x, y]
        });
      } else if (letter === "C") {
        const points = pairs(args);
        out.push({
          code: "C",
          args: points
        });
        nextCubic = [points[2], points[3]];
        x = points[4];
        y = points[5];
      } else if (letter === "S") {
        const points = pairs(args);
        const first = cubicControl ? [2 * x - cubicControl[0], 2 * y - cubicControl[1]] : [x, y];
        out.push({
          code: "C",
          args: [...first, ...points]
        });
        nextCubic = [points[0], points[1]];
        x = points[2];
        y = points[3];
      } else if (letter === "Q") {
        const points = pairs(args);
        out.push({
          code: "Q",
          args: points
        });
        nextQuadratic = [points[0], points[1]];
        x = points[2];
        y = points[3];
      } else if (letter === "T") {
        const points = pairs(args);
        const control = quadraticControl ? [2 * x - quadraticControl[0], 2 * y - quadraticControl[1]] : [x, y];
        out.push({
          code: "Q",
          args: [...control, ...points]
        });
        nextQuadratic = control;
        x = points[0];
        y = points[1];
      } else if (letter === "A") {
        const endX = args[5] + dx;
        const endY = args[6] + dy;
        out.push(...arcToCubics(x, y, args[0], args[1], args[2], args[3], args[4], endX, endY));
        x = endX;
        y = endY;
      } else if (letter === "Z") {
        out.push({
          code: "Z",
          args: []
        });
        x = startX;
        y = startY;
      }
      cubicControl = nextCubic;
      quadraticControl = nextQuadratic;
    }
    return out;
  };
  const arcToCubics = (x1, y1, rx, ry, rotation, largeArc, sweep, x2, y2) => {
    if (x1 === x2 && y1 === y2) return [];
    let radiusX = Math.abs(rx);
    let radiusY = Math.abs(ry);
    if (radiusX === 0 || radiusY === 0) return [{
      code: "L",
      args: [x2, y2]
    }];
    const phi = rotation * Math.PI / 180;
    const cosPhi = Math.cos(phi);
    const sinPhi = Math.sin(phi);
    const midX = (x1 - x2) / 2;
    const midY = (y1 - y2) / 2;
    const primeX = cosPhi * midX + sinPhi * midY;
    const primeY = -sinPhi * midX + cosPhi * midY;
    const oversize = primeX * primeX / (radiusX * radiusX) + primeY * primeY / (radiusY * radiusY);
    if (oversize > 1) {
      const grow = Math.sqrt(oversize);
      radiusX *= grow;
      radiusY *= grow;
    }
    const denominator = radiusX * radiusX * primeY * primeY + radiusY * radiusY * primeX * primeX;
    const numerator = radiusX * radiusX * radiusY * radiusY - radiusX * radiusX * primeY * primeY - radiusY * radiusY * primeX * primeX;
    const factor = (largeArc === sweep ? -1 : 1) * Math.sqrt(Math.max(0, numerator) / denominator);
    const centrePrimeX = factor * radiusX * primeY / radiusY;
    const centrePrimeY = -factor * radiusY * primeX / radiusX;
    const centreX = cosPhi * centrePrimeX - sinPhi * centrePrimeY + (x1 + x2) / 2;
    const centreY = sinPhi * centrePrimeX + cosPhi * centrePrimeY + (y1 + y2) / 2;
    const angle = (ux, uy, vx, vy) => {
      const length = Math.hypot(ux, uy) * Math.hypot(vx, vy);
      const cosine = length === 0 ? 1 : Math.min(1, Math.max(-1, (ux * vx + uy * vy) / length));
      return (ux * vy - uy * vx < 0 ? -1 : 1) * Math.acos(cosine);
    };
    const fromX = (primeX - centrePrimeX) / radiusX;
    const fromY = (primeY - centrePrimeY) / radiusY;
    const toX = (-primeX - centrePrimeX) / radiusX;
    const toY = (-primeY - centrePrimeY) / radiusY;
    const start = angle(1, 0, fromX, fromY);
    let sweptAngle = angle(fromX, fromY, toX, toY);
    if (!sweep && sweptAngle > 0) sweptAngle -= 2 * Math.PI;
    if (sweep && sweptAngle < 0) sweptAngle += 2 * Math.PI;
    const steps = Math.max(1, Math.ceil(Math.abs(sweptAngle) / (Math.PI / 2)));
    const step = sweptAngle / steps;
    const handle = 4 / 3 * Math.tan(step / 4);
    const at = t => [centreX + radiusX * Math.cos(t) * cosPhi - radiusY * Math.sin(t) * sinPhi, centreY + radiusX * Math.cos(t) * sinPhi + radiusY * Math.sin(t) * cosPhi];
    const slope = t => [-radiusX * Math.sin(t) * cosPhi - radiusY * Math.cos(t) * sinPhi, -radiusX * Math.sin(t) * sinPhi + radiusY * Math.cos(t) * cosPhi];
    const out = [];
    for (let index = 0; index < steps; index += 1) {
      const from = start + index * step;
      const to = from + step;
      const [ax, ay] = at(from);
      const [bx, by] = at(to);
      const [aSlopeX, aSlopeY] = slope(from);
      const [bSlopeX, bSlopeY] = slope(to);
      out.push({
        code: "C",
        args: [ax + handle * aSlopeX, ay + handle * aSlopeY, bx - handle * bSlopeX, by - handle * bSlopeY, bx, by]
      });
    }
    const last = out[out.length - 1];
    last.args[4] = x2;
    last.args[5] = y2;
    return out;
  };
  const transformPathData = (segments, matrix) => segments.map(({code, args}) => {
    const moved = [];
    for (let index = 0; index + 1 < args.length; index += 2) {
      const x = args[index];
      const y = args[index + 1];
      moved.push(matrix.a * x + matrix.c * y + matrix.e, matrix.b * x + matrix.d * y + matrix.f);
    }
    return {
      code,
      args: moved
    };
  });
  const fitMatrix = (source, target) => {
    const chosen = Math.min(target.width / source.width, target.height / source.height);
    const scale = Number.isFinite(chosen) && chosen > 0 ? chosen : 1;
    return {
      a: scale,
      b: 0,
      c: 0,
      d: scale,
      e: target.x + target.width / 2 - (source.x + source.width / 2) * scale,
      f: target.y + target.height / 2 - (source.y + source.height / 2) * scale
    };
  };
  const printPathData = segments => segments.map(({code, args}) => {
    if (args.length === 0) return code;
    const numbers = args.map(value => {
      const rounded = Math.round(value * 100) / 100;
      return String(Object.is(rounded, -0) ? 0 : rounded);
    });
    return `${code} ${numbers.join(" ")}`;
  }).join(" ");
  const shapePathData = (tag, attrs) => {
    const number = (name, fallback = 0) => {
      const value = parseFloat(attrs[name]);
      return Number.isFinite(value) ? value : fallback;
    };
    if (tag === "path") {
      const d = typeof attrs.d === "string" ? attrs.d.trim() : "";
      return d === "" ? null : d;
    }
    if (tag === "rect") {
      const width = number("width");
      const height = number("height");
      if (!(width > 0) || !(height > 0)) return null;
      const x = number("x");
      const y = number("y");
      const declaredX = parseFloat(attrs.rx);
      const declaredY = parseFloat(attrs.ry);
      const rawX = Number.isFinite(declaredX) ? declaredX : declaredY;
      const rawY = Number.isFinite(declaredY) ? declaredY : declaredX;
      const rx = Math.min(Math.max(Number.isFinite(rawX) ? rawX : 0, 0), width / 2);
      const ry = Math.min(Math.max(Number.isFinite(rawY) ? rawY : 0, 0), height / 2);
      if (rx === 0 || ry === 0) {
        return `M ${x} ${y} H ${x + width} V ${y + height} H ${x} Z`;
      }
      return [`M ${x + rx} ${y}`, `H ${x + width - rx}`, `A ${rx} ${ry} 0 0 1 ${x + width} ${y + ry}`, `V ${y + height - ry}`, `A ${rx} ${ry} 0 0 1 ${x + width - rx} ${y + height}`, `H ${x + rx}`, `A ${rx} ${ry} 0 0 1 ${x} ${y + height - ry}`, `V ${y + ry}`, `A ${rx} ${ry} 0 0 1 ${x + rx} ${y}`, "Z"].join(" ");
    }
    if (tag === "circle" || tag === "ellipse") {
      const rx = tag === "circle" ? number("r") : number("rx");
      const ry = tag === "circle" ? number("r") : number("ry");
      if (!(rx > 0) || !(ry > 0)) return null;
      const cx = number("cx");
      const cy = number("cy");
      return [`M ${cx - rx} ${cy}`, `A ${rx} ${ry} 0 1 0 ${cx + rx} ${cy}`, `A ${rx} ${ry} 0 1 0 ${cx - rx} ${cy}`, "Z"].join(" ");
    }
    if (tag === "line") {
      const x1 = number("x1");
      const y1 = number("y1");
      const x2 = number("x2");
      const y2 = number("y2");
      if (x1 === x2 && y1 === y2) return null;
      return `M ${x1} ${y1} L ${x2} ${y2}`;
    }
    if (tag === "polyline" || tag === "polygon") {
      const values = String(attrs.points ?? "").trim().split(/[\s,]+/).map(Number).filter(value => Number.isFinite(value));
      if (values.length < 4) return null;
      const steps = [`M ${values[0]} ${values[1]}`];
      for (let index = 2; index + 1 < values.length; index += 2) {
        steps.push(`L ${values[index]} ${values[index + 1]}`);
      }
      if (tag === "polygon") steps.push("Z");
      return steps.join(" ");
    }
    return null;
  };
  const svgToPathData = (svgText, targetPathData, doc = document) => {
    const NS = "http://www.w3.org/2000/svg";
    const parsed = new DOMParser().parseFromString(String(svgText), "image/svg+xml");
    if (parsed.getElementsByTagName("parsererror").length > 0 || !parsed.documentElement || parsed.documentElement.localName !== "svg") {
      throw new Error("That file is not an SVG, or its markup is malformed.");
    }
    const host = doc.createElement("div");
    host.setAttribute("aria-hidden", "true");
    host.style.cssText = "position:fixed;left:-99999px;top:0;width:600px;height:600px;overflow:hidden;";
    const svg = doc.importNode(parsed.documentElement, true);
    host.appendChild(svg);
    doc.body.appendChild(host);
    try {
      const reference = doc.createElementNS(NS, "g");
      svg.appendChild(reference);
      const rootMatrix = reference.getScreenCTM();
      const defining = ["defs", "clipPath", "mask", "symbol", "marker", "pattern"];
      const isDefinition = element => {
        for (let node = element.parentNode; node && node !== svg; node = node.parentNode) {
          if (defining.includes(node.localName)) return true;
        }
        return false;
      };
      const shapes = [...svg.querySelectorAll("path,rect,circle,ellipse,line,polyline,polygon")];
      const segments = [];
      let shapesUsed = 0;
      let firstProblem = null;
      for (const element of shapes) {
        if (isDefinition(element)) continue;
        if (doc.defaultView.getComputedStyle(element).display === "none") continue;
        const attrs = {};
        for (const attribute of element.attributes) attrs[attribute.localName] = attribute.value;
        const d = shapePathData(element.localName, attrs);
        if (d === null) continue;
        let own;
        try {
          own = normalisePathData(parsePathData(d));
        } catch (error) {
          firstProblem = firstProblem ?? error.message;
          continue;
        }
        const matrix = element.getScreenCTM();
        segments.push(...rootMatrix && matrix ? transformPathData(own, rootMatrix.inverse().multiply(matrix)) : own);
        shapesUsed += 1;
      }
      if (segments.length === 0) {
        if (firstProblem) throw new Error(`This SVG has unreadable path data: ${firstProblem}.`);
        const untraceable = ["text", "image", "use"].find(tag => svg.getElementsByTagName(tag).length > 0);
        throw new Error(untraceable ? `This SVG draws with <${untraceable}>, which has no outline to trace. Convert it to paths and try again.` : "This SVG has no shapes to import.");
      }
      const probe = doc.createElementNS(NS, "path");
      svg.appendChild(probe);
      probe.setAttribute("d", printPathData(segments));
      const source = probe.getBBox();
      if (!(source.width > 0) || !(source.height > 0)) {
        if (!(source.width > 0) && !(source.height > 0)) {
          throw new Error("This SVG's shapes have no size.");
        }
      }
      probe.setAttribute("d", String(targetPathData));
      const target = probe.getBBox();
      return {
        d: printPathData(transformPathData(segments, fitMatrix(source, target))),
        shapes: shapesUsed
      };
    } finally {
      host.remove();
    }
  };
  const granularity = value => {
    const decimals = String(value).split(".")[1];
    return decimals ? Number(`1e-${decimals.length}`) : 1;
  };
  const readout = (variable, value) => {
    if (variable.type === "number") return "";
    if (variable.type === "color") return String(value);
    if (variable.type === "enum") {
      const hit = (variable.options ?? []).find(o => o.value === value);
      return hit ? hit.label ?? hit.value : String(value);
    }
    return "";
  };
  const control = (variable, value, onChange, note, onNote, onTyping) => {
    const options = variable.options ?? [];
    if (variable.type === "enum" && options.length > 0 && options.length <= 4) {
      return <div className="hf-ve-seg">
          {options.map(o => <button key={o.value} type="button" data-on={value === o.value} aria-pressed={value === o.value} onClick={() => onChange(o.value)} className="hf-ve-seg-btn hf-ve-tint">
              {o.label ?? o.value}
            </button>)}
        </div>;
    }
    if (variable.type === "enum") {
      return <select className="hf-ve-field hf-ve-select hf-ve-tint" value={value} aria-label={variable.label ?? variable.id} onChange={e => onChange(e.target.value)}>
          {options.map(o => <option key={o.value} value={o.value}>
              {o.label ?? o.value}
            </option>)}
        </select>;
    }
    if (variable.type === "number") {
      const min = Number(variable.min);
      const max = Number(variable.max);
      const unit = variable.unit ?? "";
      const declaredStep = Number(variable.step);
      const step = declaredStep > 0 ? declaredStep : 1;
      const label = variable.label ?? variable.id;
      if (!(Number.isFinite(min) && Number.isFinite(max) && max > min)) {
        return <input type="number" className="hf-ve-field hf-ve-mono hf-ve-tint" value={value} min={Number.isFinite(min) ? min : undefined} max={Number.isFinite(max) ? max : undefined} step={declaredStep > 0 ? declaredStep : granularity(variable.default)} aria-label={label} onChange={e => {
          const next = Number(e.target.value);
          if (e.target.value !== "" && Number.isFinite(next)) onChange(next);
        }} />;
      }
      const at = n => Math.min(1, Math.max(0, (Number(n) - min) / (max - min)));
      const now = at(value);
      const authored = at(variable.default);
      const place = fraction => ({
        offset: `${fraction * 100}%`,
        nudge: `${(0.5 - fraction) * 16}px`
      });
      const value_ = place(now);
      const default_ = place(authored);
      const grain = event => {
        event.currentTarget.step = event.shiftKey ? step / 10 : step;
      };
      return <div className="hf-ve-slider" style={{
        "--ve-fill": value_.offset,
        "--ve-fill-nudge": value_.nudge,
        "--ve-default": default_.offset,
        "--ve-default-nudge": default_.nudge
      }}>
          {}
          <div className="hf-ve-ruler" data-near={now < 0.14 ? "min" : now > 0.86 ? "max" : ""} aria-hidden="true">
            <span className="hf-ve-bound" data-end="min">
              {min}
            </span>
            <span className="hf-ve-bound" data-end="max">
              {max}
            </span>
            <span className="hf-ve-readout">
              {value}
              {unit}
            </span>
          </div>
          <span className="hf-ve-track">
            <input type="range" className="hf-ve-range" min={min} max={max} step={step} value={value} aria-label={label} aria-valuetext={`${value}${unit}`} onChange={e => onChange(Number(e.target.value))} onPointerDown={grain} onKeyDown={grain} onDoubleClick={() => onChange(variable.default)} />
            {}
            {Math.abs(now - authored) > 0.04 && <span className="hf-ve-default" aria-hidden="true" />}
          </span>
        </div>;
    }
    if (variable.type === "boolean") {
      const on = value === true || value === "true";
      return <button type="button" role="switch" aria-checked={on} aria-label={variable.label ?? variable.id} data-on={on} onClick={() => onChange(!on)} className="hf-ve-switch">
          <span className="hf-ve-switch-dot" />
        </button>;
    }
    if (variable.type === "color") {
      return <div className="flex items-center gap-2">
          <input type="color" className="hf-ve-swatch hf-ve-tint" value={value} aria-label={variable.label ?? variable.id} onChange={e => onChange(e.target.value)} />
          <input type="text" className="hf-ve-field hf-ve-mono hf-ve-tint" value={value} onChange={e => onChange(e.target.value)} onFocus={() => onTyping(variable.id)} onBlur={() => onTyping(null)} onKeyDown={e => {
        if (e.key === "Enter") e.currentTarget.blur();
      }} />
        </div>;
    }
    if (isSvgPathData(variable.default)) {
      const fileId = `hf-ve-file-${variable.id}`;
      const noteId = `hf-ve-note-${variable.id}`;
      const receive = file => {
        if (!file) return;
        file.text().then(text => {
          const {d, shapes} = svgToPathData(text, variable.default);
          onChange(d);
          onNote({
            tone: "ok",
            message: `${file.name}: ${shapes} shape${shapes === 1 ? "" : "s"} scaled to fit.`
          });
        }).catch(error => onNote({
          tone: "error",
          message: error.message
        }));
      };
      return <div className="hf-ve-drop" onDragOver={event => {
        event.preventDefault();
        event.currentTarget.dataset.over = "true";
      }} onDragLeave={event => {
        event.currentTarget.dataset.over = "false";
      }} onDrop={event => {
        event.preventDefault();
        event.currentTarget.dataset.over = "false";
        receive(event.dataTransfer.files[0]);
      }}>
          {}
          <div className="hf-ve-dropzone">
            <button type="button" className="hf-ve-btn hf-ve-tint" onClick={() => document.getElementById(fileId).click()}>
              Import SVG
            </button>
            <input id={fileId} type="file" accept=".svg,image/svg+xml" className="hf-ve-file" tabIndex={-1} aria-hidden="true" onChange={event => {
        receive(event.target.files[0]);
        event.target.value = "";
      }} />
            {}
            <p id={noteId} role="status" className="hf-ve-note" data-tone={note ? note.tone : ""}>
              {note ? note.message : "Or drop one here. Scaled to fit and centred."}
            </p>
          </div>
          <details className="hf-ve-advanced">
            <summary>Path data</summary>
            <input type="text" className="hf-ve-field hf-ve-mono hf-ve-tint" value={value} aria-label={variable.label ?? variable.id} onChange={e => onChange(e.target.value)} onFocus={() => onTyping(variable.id)} onBlur={() => onTyping(null)} onKeyDown={e => {
        if (e.key === "Enter") e.currentTarget.blur();
      }} />
          </details>
        </div>;
    }
    return <input type="text" className="hf-ve-field hf-ve-tint" value={value} aria-label={variable.label ?? variable.id} onChange={e => onChange(e.target.value)} onFocus={() => onTyping(variable.id)} onBlur={() => onTyping(null)} onKeyDown={e => {
      if (e.key === "Enter") e.currentTarget.blur();
    }} />;
  };
  const variablesKey = JSON.stringify(variables);
  const defaults = useMemo(() => {
    const built = {};
    for (const v of variables) if (v.default !== undefined) built[v.id] = v.default;
    return built;
  }, [variablesKey]);
  const urlKey = `vars-${compositionId}`;
  const readFromUrl = () => {
    if (typeof window === "undefined") return {};
    try {
      const raw = new URLSearchParams(window.location.search).get(urlKey);
      if (!raw) return {};
      const parsed = JSON.parse(raw);
      if (!parsed || typeof parsed !== "object" || Array.isArray(parsed)) return {};
      const declared = new Set(variables.map(v => v.id));
      return Object.fromEntries(Object.entries(parsed).filter(([id]) => declared.has(id)));
    } catch {
      return {};
    }
  };
  const [values, setValues] = useState(() => ({
    ...defaults,
    ...readFromUrl()
  }));
  useEffect(() => {
    const fromUrl = readFromUrl();
    if (Object.keys(fromUrl).length > 0) setValues(current => ({
      ...current,
      ...fromUrl
    }));
  }, []);
  useEffect(() => {
    if (typeof window === "undefined") return;
    const changed = Object.fromEntries(Object.entries(values).filter(([id, value]) => JSON.stringify(value) !== JSON.stringify(defaults[id])));
    const url = new URL(window.location.href);
    if (Object.keys(changed).length === 0) url.searchParams.delete(urlKey); else url.searchParams.set(urlKey, JSON.stringify(changed));
    const next = url.toString();
    if (next !== window.location.href) {
      window.history.replaceState(null, "", next);
      window.dispatchEvent(new CustomEvent("hf-vars-changed"));
    }
  }, [values, defaults, urlKey]);
  const [notes, setNotes] = useState({});
  const [typing, setTyping] = useState(null);
  const posted = useRef(null);
  const [tab, setTab] = useState("preview");
  const frame = useRef(null);
  const bootstrap = ["<!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>", "(function(){", `  var PAYLOAD = ${JSON.stringify(previewSrc)};`, `  var INITIAL = ${JSON.stringify({
    ...defaults,
    ...readFromUrl()
  })};`, "  var html = null, player = null, poll = null;", "  function withValues(source, values) {", "    var json = JSON.stringify(values);", "    var attr = json.replace(/'/g, '&#39;');", "    var out = source.replace(/\\sdata-variable-values=(?:\"[^\"]*\"|'[^']*')/gi, '');", "    out = out.replace(/(data-composition-src=)/gi, \"data-variable-values='\" + attr + \"' $1\");", "    var tag = '<' + 'script>window.__hfVariables=' + json + ';<' + '/script>';", "    return /<head[^>]*>/i.test(out)", "      ? out.replace(/<head([^>]*)>/i, '<head$1>' + tag)", "      : tag + out;", "  }", "  function arm(resumeAt) {", "    clearInterval(poll);", "    var last = -1, tries = 0, seeked = false;", "    poll = setInterval(function () {", "      if (player.ready) {", "        if (!seeked) { seeked = true; if (resumeAt > 0) player.seek(resumeAt); }", "        player.play();", "      }", "      if (seeked && player.currentTime > 0 && player.currentTime !== last) {", "        clearInterval(poll); return;", "      }", "      last = player.currentTime;", "      if (++tries > 150) clearInterval(poll);", "    }, 100);", "  }", "  function mount(values, resumeAt) {", "    if (html === null) return;", "    player.setAttribute('srcdoc', withValues(html, values));", "    arm(resumeAt || 0);", "  }", "  player = document.createElement('hyperframes-player');", "  player.setAttribute('controls', ''); player.setAttribute('muted', '');", "  document.body.appendChild(player);", "  player.addEventListener('ended', function () { player.seek(0); player.play(); });", "  fetch(PAYLOAD).then(function (r) { return r.json(); }).then(function (d) {", "    html = d.html; mount(INITIAL, 0);", "  }).catch(function (e) {", "    document.body.innerHTML = '<pre style=\"color:#f66;font:12px monospace;padding:12px\">preview unavailable: ' + e + '</pre>';", "  });", "  addEventListener('message', function (event) {", "    var values = event.data && event.data.hfVariables;", "    if (!values) return;", "    mount(values, player.currentTime || 0);", "  });", "})();", "</" + "script></body></html>"].join("");
  useEffect(() => {
    if (typing !== null) return;
    const payload = JSON.stringify(values);
    if (payload === posted.current) return;
    const timer = setTimeout(() => {
      const target = frame.current && frame.current.contentWindow;
      if (!target) return;
      posted.current = payload;
      target.postMessage({
        hfVariables: values
      }, window.location.origin);
    }, 150);
    return () => clearTimeout(timer);
  }, [values, typing]);
  const printed = JSON.stringify(values, null, 2).split("\n").join("\n  ");
  const attributes = [["data-composition-id", `"${compositionId}"`], ["data-composition-src", `"${compositionSrc}"`], ["data-variable-values", `'${printed}'`]];
  const snippetLines = [[[SHIKI.punct, "<"], [SHIKI.tag, "div"]]];
  for (const [name, literal] of attributes) {
    const [head, ...rest] = literal.split("\n");
    snippetLines.push([[SHIKI.attr, `  ${name}`], [SHIKI.equals, "="], [SHIKI.value, head]]);
    for (const line of rest) snippetLines.push([[SHIKI.value, line]]);
  }
  snippetLines.push([[SHIKI.punct, "></"], [SHIKI.tag, "div"], [SHIKI.punct, ">"]]);
  const dirty = variables.some(v => values[v.id] !== defaults[v.id]);
  const installCommand = (() => {
    const base = `npx hyperframes add ${compositionId}`;
    if (!dirty) return base;
    const changed = {};
    for (const v of variables) {
      if (JSON.stringify(values[v.id]) !== JSON.stringify(defaults[v.id])) changed[v.id] = values[v.id];
    }
    return `${base} --vars '${JSON.stringify(changed)}'`;
  })();
  const TABS = [["preview", "Preview"], ...children ? [["code", "Code"]] : [], ["snippet", "Snippet"]];
  return <div className="hf-ve not-prose my-4">
      <style dangerouslySetInnerHTML={{
    __html: CSS
  }} />

      <div className="mb-3 flex items-center gap-3">
        <div className="hf-ve-tabs">
          {TABS.map(([id, label]) => <button key={id} type="button" data-on={tab === id} aria-pressed={tab === id} onClick={() => setTab(id)} className="hf-ve-tab hf-ve-tint">
              {label}
            </button>)}
        </div>
      </div>

      {}
      <div className="hf-ve-frame">
        <div className="hf-ve-cell" data-on={tab === "preview"}>
          <iframe ref={frame} srcDoc={bootstrap} className="hf-ve-preview block aspect-video w-full" title={`${compositionId} preview`} />
        </div>
        {children && <div className="hf-ve-cell" data-on={tab === "code"}>
            {children}
          </div>}
        <div className="hf-ve-cell hf-ve-snippet" data-on={tab === "snippet"}>
          {}
          <CodeBlock filename="Terminal">
            <pre className="shiki shiki-themes github-light-default dark-plus" style={{
    backgroundColor: "rgb(255, 255, 255)",
    "--shiki-dark-bg": "#0B0C0E",
    color: "rgb(31, 35, 40)",
    "--shiki-dark": "#D4D4D4"
  }}>
              <code>
                <span className="line">
                  <span style={SHIKI.value}>{installCommand}</span>
                  {"\n"}
                </span>
              </code>
            </pre>
          </CodeBlock>
          {}
          <CodeBlock filename="index.html">
            <pre className="shiki shiki-themes github-light-default dark-plus" style={{
    backgroundColor: "rgb(255, 255, 255)",
    "--shiki-dark-bg": "#0B0C0E",
    color: "rgb(31, 35, 40)",
    "--shiki-dark": "#D4D4D4"
  }}>
              <code>
                {snippetLines.map((tokens, line) => <span key={line} className="line">
                    {tokens.map(([style, text], token) => <span key={token} style={style}>
                        {text}
                      </span>)}
                    {"\n"}
                  </span>)}
              </code>
            </pre>
          </CodeBlock>
        </div>
      </div>

      <div className="hf-ve-panel">
        <div className="hf-ve-head">
          <span className="hf-ve-title">Customize</span>
          <button type="button" onClick={() => {
    setValues(defaults);
    setNotes({});
  }} disabled={!dirty} className="hf-ve-btn hf-ve-tint">
            Reset
          </button>
        </div>
        <div className="hf-ve-grid">
          {variables.map(v => <div key={v.id}>
              <div className="hf-ve-row">
                <label className="hf-ve-label">{v.label ?? v.id}</label>
                <span className="hf-ve-value">{readout(v, values[v.id])}</span>
              </div>
              {control(v, values[v.id], next => setValues(prev => ({
    ...prev,
    [v.id]: next
  })), notes[v.id], note => setNotes(prev => ({
    ...prev,
    [v.id]: note
  })), setTyping)}
              {v.description && <p className="hf-ve-desc">{v.description}</p>}
            </div>)}
        </div>
      </div>
    </div>;
};

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>;
};

<VariablesExplorer previewSrc="/public/catalog/components/whiteboard-ink.json" compositionId="whiteboard-ink" compositionSrc="compositions/components/whiteboard-ink.html" variables={[{"id":"sketch","type":"enum","role":"content","label":"Sketch","description":"Authored preset sketch to draw. Ignored when the strokes slot holds custom paths.","default":"bulb","options":[{"value":"bulb","label":"Bulb"},{"value":"flow","label":"Flow"},{"value":"rocket","label":"Rocket"}]},{"id":"caption","type":"string","role":"content","label":"Caption","description":"Short line shown after the sketch completes.","default":"Draw the idea"},{"id":"pen","type":"enum","role":"style","label":"Pen","description":"Show or hide the pen nib actor.","default":"show","options":[{"value":"show","label":"Show"},{"value":"hide","label":"Hide"}]},{"id":"accent","type":"enum","role":"style","label":"Accent","description":"Color used by strokes marked data-ink=accent (one highlight stroke in each preset).","default":"green","options":[{"value":"green","label":"Green"},{"value":"blue","label":"Blue"},{"value":"violet","label":"Violet"}]},{"id":"exit","type":"enum","role":"style","label":"Exit","description":"How the completed lockup leaves. none holds the final frame.","default":"none","options":[{"value":"none","label":"None"},{"value":"fade","label":"Fade"},{"value":"up","label":"Up"}]}]}>
  ```html whiteboard-ink.html theme={null}
  <!doctype html>
  <!--
    whiteboard-ink: HyperFrames video primitive (intros and reveals / ink draw)

    A hand-authored SVG sketch draws one stroke at a time while a pen nib
    samples the active path tip. The nib follows getPointAtLength during each
    draw and takes a short lifted hop between strokes.

    Strokes slot: the SVG ships an empty <g data-slot="strokes"> group. Fill it
    with your own <path> elements (in your installed copy) and those paths
    become the drawing; the sketch enum is ignored while the slot has paths.
    Mark one path data-ink="accent" to route it through the accent token map.
    Nib riding, per-stroke cadence, and the ink law are identical for slot
    strokes and presets.

    Variables:
      - sketch (bulb / flow / rocket): authored preset sketch; ignored when the
        strokes slot holds paths.
      - caption (string): short line shown after the drawing completes.
      - pen (show / hide): visibility of the traveling nib actor.
      - accent (green / blue / violet): one highlight stroke routed through a
        distinct contract token.
      - exit (none / fade / up): how the completed lockup leaves. none holds
        the final frame (frame roots own transitions); fade releases opacity
        only; up adds the small upward drift.

    Envelope, fixed IN and OUT with elastic HOLD only:
      IN_BASE  = 3.55s, 3.25s sequential draw phase, then pen exit and caption
      HOLD     = max(0, D - IN - OUT), dead-calm completed lockup
      OUT_BASE = 0.45s when exit is fade or up, otherwise 0 (hold to the end)
      If D is shorter than IN_BASE + OUT_BASE, IN and OUT compress together.
      The timeline is never time-scaled.

    Ink law: every selected path is measured once with getTotalLength. That
    measurement owns its dash array, dash offset, cadence weight, and nib
    sampling. Dashed geometry stays in native SVG user units.

    Mount contract: the runtime clones only this template. #root fills the host
    box, establishes the container query basis, has no data-width or data-height,
    and registers one paused timeline under the literal whiteboard-ink key.
  -->
  <html
    lang="en"
    data-composition-id="whiteboard-ink"
    data-composition-duration="5"
    data-composition-variables='[
      { "id": "sketch", "type": "enum", "role": "content", "label": "Sketch", "description": "Authored preset sketch to draw. Ignored when the strokes slot holds custom paths.", "default": "bulb", "options": [{ "value": "bulb", "label": "Bulb" }, { "value": "flow", "label": "Flow" }, { "value": "rocket", "label": "Rocket" }] },
      { "id": "caption", "type": "string", "role": "content", "label": "Caption", "description": "Short line shown after the sketch completes.", "default": "Draw the idea" },
      { "id": "pen", "type": "enum", "role": "style", "label": "Pen", "description": "Show or hide the pen nib actor.", "default": "show", "options": [{ "value": "show", "label": "Show" }, { "value": "hide", "label": "Hide" }] },
      { "id": "accent", "type": "enum", "role": "style", "label": "Accent", "description": "Color used by strokes marked data-ink=accent (one highlight stroke in each preset).", "default": "green", "options": [{ "value": "green", "label": "Green" }, { "value": "blue", "label": "Blue" }, { "value": "violet", "label": "Violet" }] },
      { "id": "exit", "type": "enum", "role": "style", "label": "Exit", "description": "How the completed lockup leaves. none holds the final frame.", "default": "none", "options": [{ "value": "none", "label": "None" }, { "value": "fade", "label": "Fade" }, { "value": "up", "label": "Up" }] }
    ]'
  >
    <head>
      <meta charset="UTF-8" />
      <title>Whiteboard Ink</title>
    </head>
    <body>
      <template>
        <div id="root" data-composition-id="whiteboard-ink" data-duration="5" data-fps="30">
          <style>
            *,
            *::before,
            *::after {
              box-sizing: border-box;
            }

            #root {
              position: absolute;
              inset: 0;
              overflow: hidden;
              container-type: size;
              isolation: isolate;
              background:
                radial-gradient(
                  ellipse at 48% 42%,
                  color-mix(in srgb, var(--bg, #f6f1e7) 96%, var(--fg, #20242b)) 0%,
                  var(--bg, #f6f1e7) 72%
                ),
                var(--bg, #f6f1e7);
              color: var(--fg, #20242b);
              font-family: var(--font-body, Inter, system-ui, sans-serif);
              pointer-events: none;
            }

            .wbi-clip {
              position: absolute;
              inset: 0;
              display: grid;
              place-items: center;
              overflow: hidden;
            }

            .wbi-stage {
              display: grid;
              grid-template-rows: minmax(0, 1fr) auto;
              width: 92cqw;
              height: 90cqh;
              opacity: 0;
              will-change: transform, opacity;
            }

            .wbi-board {
              position: relative;
              min-height: 0;
            }

            .wbi-svg {
              display: block;
              width: 100%;
              height: 100%;
              overflow: visible;
            }

            .wbi-sketch[hidden] {
              display: none;
            }

            .wbi-stroke {
              fill: none;
              stroke: var(--fg, #20242b);
              /* User-space width: never non-scaling-stroke on dashed paths
                 (screen-space dash breaks draw-on under group scale). Non-uniform
                 scale gives a natural thick-thin nib variation. */
              stroke-width: 6;
              stroke-linecap: round;
              stroke-linejoin: round;
            }

            .wbi-stroke.wbi-accent {
              stroke: var(--wbi-accent);
            }

            /* Custom strokes-slot paths inherit the same ink treatment without
               needing any class; data-ink="accent" routes through the accent
               token map exactly like a preset's highlight stroke. */
            [data-slot="strokes"] path {
              fill: none;
              stroke: var(--fg, #20242b);
              stroke-width: 6;
              stroke-linecap: round;
              stroke-linejoin: round;
            }

            [data-slot="strokes"] path[data-ink="accent"] {
              stroke: var(--wbi-accent);
            }

            .wbi-pen {
              filter: drop-shadow(0 5px 6px color-mix(in srgb, var(--fg, #20242b) 20%, transparent));
              will-change: transform, opacity;
            }

            .wbi-pen-art {
              will-change: transform;
            }

            .wbi-pen-body {
              fill: var(--surface, #ffffff);
              stroke: var(--fg, #20242b);
              stroke-width: 4;
              stroke-linecap: round;
              stroke-linejoin: round;
            }

            .wbi-pen-nib {
              fill: var(--wbi-accent);
              stroke: var(--fg, #20242b);
              stroke-width: 3;
            }

            .wbi-caption {
              min-height: 10cqh;
              padding-top: var(--space-1, 1.8cqh);
              color: var(--muted, #667085);
              font-family: var(--font-display, Inter, system-ui, sans-serif);
              font-size: clamp(24px, 5cqh, 52px);
              font-weight: 680;
              line-height: 1.1;
              letter-spacing: -0.02em;
              text-align: center;
              opacity: 0;
            }
          </style>

          <div
            id="wbi-clip"
            class="wbi-clip clip"
            data-start="0"
            data-duration="5"
            data-track-index="0"
          >
            <div class="wbi-stage" role="img">
              <div class="wbi-board">
                <svg
                  class="wbi-svg"
                  viewBox="0 0 1000 560"
                  preserveAspectRatio="xMidYMid meet"
                  aria-hidden="true"
                >
                  <g
                    class="wbi-sketch"
                    data-sketch="bulb"
                    transform="translate(500 280) scale(1.25 1.4) translate(-500 -256)"
                  >
                    <path
                      class="wbi-stroke"
                      d="M 430 340 C 414 310 392 286 386 244 C 376 172 427 113 501 109 C 578 105 633 160 626 235 C 622 279 596 306 574 341"
                    ></path>
                    <path
                      class="wbi-stroke wbi-accent"
                      d="M 454 238 C 469 251 482 263 499 292 C 517 261 532 247 549 235"
                    ></path>
                    <path class="wbi-stroke" d="M 431 347 C 468 353 531 350 571 343"></path>
                    <path class="wbi-stroke" d="M 438 369 C 476 376 525 373 564 365"></path>
                    <path class="wbi-stroke" d="M 454 389 C 482 403 520 402 548 385"></path>
                    <path class="wbi-stroke" d="M 333 231 C 349 228 360 230 372 232"></path>
                    <path class="wbi-stroke" d="M 640 228 C 657 225 670 226 685 230"></path>
                  </g>

                  <g
                    class="wbi-sketch"
                    data-sketch="flow"
                    transform="translate(500 280) scale(0.9 2.1) translate(-525 -265)"
                    hidden
                  >
                    <path
                      class="wbi-stroke"
                      d="M 145 205 C 145 184 160 171 184 171 L 315 171 C 338 171 351 187 351 207 L 351 322 C 351 344 337 357 314 357 L 181 357 C 158 357 145 342 145 321 Z"
                    ></path>
                    <path
                      class="wbi-stroke wbi-accent"
                      d="M 352 264 C 378 258 397 259 425 263 L 446 267 M 429 249 L 446 267 L 427 284"
                    ></path>
                    <path class="wbi-stroke" d="M 516 170 L 611 265 L 516 360 L 421 265 Z"></path>
                    <path
                      class="wbi-stroke"
                      d="M 612 265 C 641 268 662 268 691 264 L 711 263 M 694 247 L 711 263 L 694 280"
                    ></path>
                    <path
                      class="wbi-stroke"
                      d="M 711 204 C 711 184 726 171 749 171 L 868 171 C 891 171 905 187 905 208 L 905 321 C 905 343 891 357 868 357 L 748 357 C 725 357 711 342 711 321 Z"
                    ></path>
                    <path
                      class="wbi-stroke"
                      d="M 764 266 C 785 284 802 292 820 294 C 837 278 849 256 861 230"
                    ></path>
                  </g>

                  <g class="wbi-sketch" data-sketch="rocket" transform="translate(0 -17)" hidden>
                    <path
                      class="wbi-stroke"
                      d="M 500 76 C 552 117 581 184 578 272 C 576 329 549 378 500 420 C 451 378 425 329 422 272 C 419 184 448 117 500 76 Z"
                    ></path>
                    <path
                      class="wbi-stroke wbi-accent"
                      d="M 500 181 C 526 181 544 198 544 223 C 544 248 527 265 500 265 C 475 265 457 248 457 223 C 457 199 474 181 500 181 Z"
                    ></path>
                    <path
                      class="wbi-stroke"
                      d="M 430 295 C 386 320 359 363 353 419 C 389 405 420 384 448 353"
                    ></path>
                    <path
                      class="wbi-stroke"
                      d="M 570 295 C 614 320 641 363 647 419 C 611 405 580 384 552 353"
                    ></path>
                    <path
                      class="wbi-stroke"
                      d="M 476 415 C 464 445 470 478 500 518 C 530 478 536 445 524 415"
                    ></path>
                    <path class="wbi-stroke" d="M 452 431 C 433 451 427 475 433 500"></path>
                    <path class="wbi-stroke" d="M 548 431 C 567 451 573 475 567 500"></path>
                  </g>

                  <!--
                    Strokes slot. Fill this group with your own <path> elements
                    (installed copy) to replace the preset sketches; paths draw
                    in document order in the 0 0 1000 560 viewBox space. Mark a
                    path data-ink="accent" for the accent token. Ships empty.
                  -->
                  <g class="wbi-sketch" data-slot="strokes" data-sketch="custom" hidden></g>

                  <g class="wbi-pen" aria-hidden="true">
                    <g class="wbi-pen-art">
                      <path class="wbi-pen-body" d="M 0 0 L -43 -11 L -52 0 L -43 11 Z"></path>
                      <path class="wbi-pen-nib" d="M 0 0 L -11 -7 L -11 7 Z"></path>
                    </g>
                  </g>
                </svg>
              </div>
              <div class="wbi-caption"></div>
            </div>
          </div>

          <script src="https://cdn.jsdelivr.net/npm/gsap@3.14.2/dist/gsap.min.js"></script>
          <script>
            (function () {
              "use strict";

              var root = document.getElementById("root");
              var stage = root.querySelector(".wbi-stage");
              var captionElement = root.querySelector(".wbi-caption");
              var penElement = root.querySelector(".wbi-pen");
              var penArt = root.querySelector(".wbi-pen-art");
              var vars =
                window.__hyperframes && window.__hyperframes.getVariables
                  ? window.__hyperframes.getVariables()
                  : {};

              var sketchGroups = {
                bulb: root.querySelector('[data-sketch="bulb"]'),
                flow: root.querySelector('[data-sketch="flow"]'),
                rocket: root.querySelector('[data-sketch="rocket"]'),
              };
              var sketch = Object.prototype.hasOwnProperty.call(sketchGroups, vars.sketch)
                ? vars.sketch
                : "bulb";
              var caption = vars.caption == null ? "Draw the idea" : String(vars.caption);
              var penVisible = vars.pen !== "hide";
              var accentColors = {
                green: "var(--brand, #71f5a7)",
                blue: "var(--accent, #61a8ff)",
                violet: "var(--accent-2, #c5a3ff)",
              };
              var accent = Object.prototype.hasOwnProperty.call(accentColors, vars.accent)
                ? vars.accent
                : "green";
              var exitModes = { none: true, fade: true, up: true };
              var exitMode = Object.prototype.hasOwnProperty.call(exitModes, vars.exit)
                ? vars.exit
                : "none";

              // Strokes slot: user-supplied paths replace the preset sketches.
              var strokesSlot = root.querySelector('[data-slot="strokes"]');
              var slotPaths = strokesSlot ? strokesSlot.querySelectorAll("path") : [];
              var hasCustomStrokes = slotPaths.length > 0;
              if (hasCustomStrokes) {
                Array.prototype.forEach.call(slotPaths, function (path) {
                  // CSS beats SVG presentation attributes; promote an authored
                  // stroke-width to inline style so it wins over the slot rule.
                  var strokeWidth = path.getAttribute("stroke-width");
                  if (strokeWidth) path.style.strokeWidth = strokeWidth;
                });
              }

              Object.keys(sketchGroups).forEach(function (name) {
                // SVG <g> has no `hidden` IDL property (assignment is a dead
                // expando); toggle the attribute so the [hidden] CSS applies.
                if (hasCustomStrokes || name !== sketch)
                  sketchGroups[name].setAttribute("hidden", "");
                else sketchGroups[name].removeAttribute("hidden");
              });
              if (hasCustomStrokes) strokesSlot.removeAttribute("hidden");
              var activeGroup = hasCustomStrokes ? strokesSlot : sketchGroups[sketch];
              root.style.setProperty("--wbi-accent", accentColors[accent]);
              captionElement.textContent = caption;
              penElement.style.display = penVisible ? "" : "none";
              stage.setAttribute(
                "aria-label",
                (hasCustomStrokes
                  ? "Custom sketch. "
                  : sketch.charAt(0).toUpperCase() + sketch.slice(1) + " sketch. ") + caption,
              );

              var groupTransform = activeGroup.transform.baseVal.consolidate();
              var strokes = Array.from(activeGroup.querySelectorAll("path")).map(function (path) {
                var length = path.getTotalLength();
                path.style.strokeDasharray = length + " " + length;
                path.style.strokeDashoffset = String(length);
                return {
                  path: path,
                  length: length,
                  progress: 0,
                  matrix: groupTransform ? groupTransform.matrix : null,
                };
              });
              var totalLength = strokes.reduce(function (sum, stroke) {
                return sum + stroke.length;
              }, 0);

              function pointAt(stroke, distance) {
                var point = stroke.path.getPointAtLength(distance);
                return stroke.matrix ? point.matrixTransform(stroke.matrix) : point;
              }

              function pathPose(stroke, progress) {
                var distance = progress * stroke.length;
                var tangentStep = Math.max(0.5, stroke.length * 0.004);
                var before = pointAt(stroke, Math.max(0, distance - tangentStep));
                var after = pointAt(stroke, Math.min(stroke.length, distance + tangentStep));
                var point = pointAt(stroke, distance);

                return {
                  x: point.x,
                  y: point.y,
                  rotation: (Math.atan2(after.y - before.y, after.x - before.x) * 180) / Math.PI,
                };
              }

              function placePen(pose) {
                gsap.set(penElement, { x: pose.x, y: pose.y, rotation: pose.rotation });
              }

              function renderStroke(stroke) {
                var clamped = Math.max(0, Math.min(1, stroke.progress));
                stroke.path.style.strokeDashoffset = String((1 - clamped) * stroke.length);
                placePen(pathPose(stroke, clamped));
              }

              var DRAW_PHASE_BASE = 3.25;
              var CAPTION_BASE = 0.3;
              var IN_BASE = DRAW_PHASE_BASE + CAPTION_BASE;
              var OUT_BASE = exitMode === "none" ? 0 : 0.45;
              var resolvedDuration =
                window.__hyperframes && window.__hyperframes.getDuration
                  ? window.__hyperframes.getDuration()
                  : undefined;
              var duration = Math.max(
                0.001,
                typeof resolvedDuration === "number"
                  ? resolvedDuration
                  : parseFloat(root.dataset.duration || "5"),
              );
              var fixedTotal = IN_BASE + OUT_BASE;
              var phaseScale = duration < fixedTotal ? duration / fixedTotal : 1;
              var IN = IN_BASE * phaseScale;
              var OUT = OUT_BASE * phaseScale;
              var HOLD = Math.max(0, duration - IN - OUT);
              var DRAW_PHASE = DRAW_PHASE_BASE * phaseScale;
              var CAPTION = CAPTION_BASE * phaseScale;
              var hopCount = strokes.length - 1;
              var HOP = 0.1 * phaseScale;
              var MIN_DRAW = 0.26 * phaseScale;
              // Custom slots can hold many strokes; when the fixed per-stroke
              // floors alone would overrun the draw phase, shrink them together
              // so the cadence stays sequential and the phase never overflows.
              var fixedNeed = MIN_DRAW * strokes.length + HOP * hopCount;
              if (fixedNeed > DRAW_PHASE) {
                var crowd = DRAW_PHASE / fixedNeed;
                HOP *= crowd;
                MIN_DRAW *= crowd;
              }
              var DRAW_BUDGET = DRAW_PHASE - HOP * hopCount;
              var LENGTH_BUDGET = Math.max(0, DRAW_BUDGET - MIN_DRAW * strokes.length);
              var OUT_START = IN + HOLD;
              var cursor = 0;

              gsap.set(stage, { opacity: 0, y: "1.2cqh" });
              gsap.set(captionElement, { opacity: 0, y: "1.4cqh" });
              gsap.set(penElement, { opacity: penVisible ? 1 : 0 });
              gsap.set(penArt, { y: 0, transformOrigin: "0px 0px" });
              placePen(pathPose(strokes[0], 0));

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

              // IN: each stroke owns one progress value. Its single onUpdate
              // paints the dash and places the nib at the same ink front.
              tl.to(
                stage,
                { opacity: 1, y: "0cqh", duration: Math.min(0.26, IN), ease: "power2.out" },
                0,
              );

              strokes.forEach(function (stroke, index) {
                var drawDuration = MIN_DRAW + (LENGTH_BUDGET * stroke.length) / totalLength;

                tl.to(
                  stroke,
                  {
                    progress: 1,
                    duration: drawDuration,
                    ease: "power1.inOut",
                    onUpdate: function () {
                      renderStroke(stroke);
                    },
                  },
                  cursor,
                );
                cursor += drawDuration;

                if (index < strokes.length - 1) {
                  var nextStroke = strokes[index + 1];
                  var fromPose = pathPose(stroke, 1);
                  var toPose = pathPose(nextStroke, 0);
                  var hopState = { progress: 0 };

                  tl.to(
                    hopState,
                    {
                      progress: 1,
                      duration: HOP,
                      ease: "power2.out",
                      onUpdate: function () {
                        var progress = hopState.progress;
                        placePen({
                          x: fromPose.x + (toPose.x - fromPose.x) * progress,
                          y:
                            fromPose.y +
                            (toPose.y - fromPose.y) * progress -
                            Math.sin(Math.PI * progress) * 18,
                          rotation:
                            fromPose.rotation + (toPose.rotation - fromPose.rotation) * progress,
                        });
                        gsap.set(penArt, { y: -Math.sin(Math.PI * progress) * 8 });
                      },
                    },
                    cursor,
                  );
                  cursor += HOP;
                }
              });

              tl.to(
                captionElement,
                { opacity: 1, y: "0cqh", duration: CAPTION, ease: "power2.out" },
                cursor,
              );
              tl.to(penElement, { opacity: 0, duration: CAPTION, ease: "power2.out" }, cursor);
              tl.to(penArt, { y: -18, duration: CAPTION, ease: "power2.out" }, cursor);

              // HOLD: the completed lockup stays dead calm. Duration changes
              // stretch only this gap between the caption reveal and OUT.

              // OUT: only when an exit is requested; exit none holds the final
              // frame to the end (frame roots own transitions).
              if (exitMode !== "none") {
                var exitTween = { opacity: 0, duration: OUT, ease: "power2.in" };
                if (exitMode === "up") exitTween.y = "-1.8cqh";
                tl.to(stage, exitTween, OUT_START);
              }

              tl.seek(0);
              window.__timelines = window.__timelines || {};
              window.__timelines["whiteboard-ink"] = tl;
            })();
          </script>
        </div>
      </template>
    </body>
  </html>
  ```
</VariablesExplorer>

## Install

<InstallCommand command="npx hyperframes add whiteboard-ink" item="whiteboard-ink" />

That writes one file: `compositions/components/whiteboard-ink.html`.

## Paste it into your composition

Open `compositions/components/whiteboard-ink.html` and copy what is inside into your own composition.

A component has no size or duration of its own. It takes both from the composition
you paste it into.

## Variables

Every one of these has a default, so the piece works untouched. Set the ones you
want to change on the element:

| Variable  | Default         | Accepts                   | What it does                                                                        |
| --------- | --------------- | ------------------------- | ----------------------------------------------------------------------------------- |
| `sketch`  | `bulb`          | `bulb`, `flow`, `rocket`  | Authored preset sketch to draw. Ignored when the strokes slot holds custom paths.   |
| `caption` | `Draw the idea` | string                    | Short line shown after the sketch completes.                                        |
| `pen`     | `show`          | `show`, `hide`            | Show or hide the pen nib actor.                                                     |
| `accent`  | `green`         | `green`, `blue`, `violet` | Color used by strokes marked data-ink=accent (one highlight stroke in each preset). |
| `exit`    | `none`          | `none`, `fade`, `up`      | How the completed lockup leaves. none holds the final frame.                        |

Set them with `data-variable-values` on the element that mounts it. These are the
defaults, so this behaves exactly like the preview above until you change one:

```html wrap theme={null}
<div
  data-composition-id="whiteboard-ink"
  data-composition-src="compositions/components/whiteboard-ink.html"
  data-variable-values='{"sketch":"bulb","caption":"Draw the idea","pen":"show","accent":"green","exit":"none"}'
></div>
```

## Source

<Accordion title={`whiteboard-ink.html`}>
  ```html theme={null}
  <!doctype html>
  <!--
    whiteboard-ink: HyperFrames video primitive (intros and reveals / ink draw)

    A hand-authored SVG sketch draws one stroke at a time while a pen nib
    samples the active path tip. The nib follows getPointAtLength during each
    draw and takes a short lifted hop between strokes.

    Strokes slot: the SVG ships an empty <g data-slot="strokes"> group. Fill it
    with your own <path> elements (in your installed copy) and those paths
    become the drawing; the sketch enum is ignored while the slot has paths.
    Mark one path data-ink="accent" to route it through the accent token map.
    Nib riding, per-stroke cadence, and the ink law are identical for slot
    strokes and presets.

    Variables:
      - sketch (bulb / flow / rocket): authored preset sketch; ignored when the
        strokes slot holds paths.
      - caption (string): short line shown after the drawing completes.
      - pen (show / hide): visibility of the traveling nib actor.
      - accent (green / blue / violet): one highlight stroke routed through a
        distinct contract token.
      - exit (none / fade / up): how the completed lockup leaves. none holds
        the final frame (frame roots own transitions); fade releases opacity
        only; up adds the small upward drift.

    Envelope, fixed IN and OUT with elastic HOLD only:
      IN_BASE  = 3.55s, 3.25s sequential draw phase, then pen exit and caption
      HOLD     = max(0, D - IN - OUT), dead-calm completed lockup
      OUT_BASE = 0.45s when exit is fade or up, otherwise 0 (hold to the end)
      If D is shorter than IN_BASE + OUT_BASE, IN and OUT compress together.
      The timeline is never time-scaled.

    Ink law: every selected path is measured once with getTotalLength. That
    measurement owns its dash array, dash offset, cadence weight, and nib
    sampling. Dashed geometry stays in native SVG user units.

    Mount contract: the runtime clones only this template. #root fills the host
    box, establishes the container query basis, has no data-width or data-height,
    and registers one paused timeline under the literal whiteboard-ink key.
  -->
  <html
    lang="en"
    data-composition-id="whiteboard-ink"
    data-composition-duration="5"
    data-composition-variables='[
      { "id": "sketch", "type": "enum", "role": "content", "label": "Sketch", "description": "Authored preset sketch to draw. Ignored when the strokes slot holds custom paths.", "default": "bulb", "options": [{ "value": "bulb", "label": "Bulb" }, { "value": "flow", "label": "Flow" }, { "value": "rocket", "label": "Rocket" }] },
      { "id": "caption", "type": "string", "role": "content", "label": "Caption", "description": "Short line shown after the sketch completes.", "default": "Draw the idea" },
      { "id": "pen", "type": "enum", "role": "style", "label": "Pen", "description": "Show or hide the pen nib actor.", "default": "show", "options": [{ "value": "show", "label": "Show" }, { "value": "hide", "label": "Hide" }] },
      { "id": "accent", "type": "enum", "role": "style", "label": "Accent", "description": "Color used by strokes marked data-ink=accent (one highlight stroke in each preset).", "default": "green", "options": [{ "value": "green", "label": "Green" }, { "value": "blue", "label": "Blue" }, { "value": "violet", "label": "Violet" }] },
      { "id": "exit", "type": "enum", "role": "style", "label": "Exit", "description": "How the completed lockup leaves. none holds the final frame.", "default": "none", "options": [{ "value": "none", "label": "None" }, { "value": "fade", "label": "Fade" }, { "value": "up", "label": "Up" }] }
    ]'
  >
    <head>
      <meta charset="UTF-8" />
      <title>Whiteboard Ink</title>
    </head>
    <body>
      <template>
        <div id="root" data-composition-id="whiteboard-ink" data-duration="5" data-fps="30">
          <style>
            *,
            *::before,
            *::after {
              box-sizing: border-box;
            }

            #root {
              position: absolute;
              inset: 0;
              overflow: hidden;
              container-type: size;
              isolation: isolate;
              background:
                radial-gradient(
                  ellipse at 48% 42%,
                  color-mix(in srgb, var(--bg, #f6f1e7) 96%, var(--fg, #20242b)) 0%,
                  var(--bg, #f6f1e7) 72%
                ),
                var(--bg, #f6f1e7);
              color: var(--fg, #20242b);
              font-family: var(--font-body, Inter, system-ui, sans-serif);
              pointer-events: none;
            }

            .wbi-clip {
              position: absolute;
              inset: 0;
              display: grid;
              place-items: center;
              overflow: hidden;
            }

            .wbi-stage {
              display: grid;
              grid-template-rows: minmax(0, 1fr) auto;
              width: 92cqw;
              height: 90cqh;
              opacity: 0;
              will-change: transform, opacity;
            }

            .wbi-board {
              position: relative;
              min-height: 0;
            }

            .wbi-svg {
              display: block;
              width: 100%;
              height: 100%;
              overflow: visible;
            }

            .wbi-sketch[hidden] {
              display: none;
            }

            .wbi-stroke {
              fill: none;
              stroke: var(--fg, #20242b);
              /* User-space width: never non-scaling-stroke on dashed paths
                 (screen-space dash breaks draw-on under group scale). Non-uniform
                 scale gives a natural thick-thin nib variation. */
              stroke-width: 6;
              stroke-linecap: round;
              stroke-linejoin: round;
            }

            .wbi-stroke.wbi-accent {
              stroke: var(--wbi-accent);
            }

            /* Custom strokes-slot paths inherit the same ink treatment without
               needing any class; data-ink="accent" routes through the accent
               token map exactly like a preset's highlight stroke. */
            [data-slot="strokes"] path {
              fill: none;
              stroke: var(--fg, #20242b);
              stroke-width: 6;
              stroke-linecap: round;
              stroke-linejoin: round;
            }

            [data-slot="strokes"] path[data-ink="accent"] {
              stroke: var(--wbi-accent);
            }

            .wbi-pen {
              filter: drop-shadow(0 5px 6px color-mix(in srgb, var(--fg, #20242b) 20%, transparent));
              will-change: transform, opacity;
            }

            .wbi-pen-art {
              will-change: transform;
            }

            .wbi-pen-body {
              fill: var(--surface, #ffffff);
              stroke: var(--fg, #20242b);
              stroke-width: 4;
              stroke-linecap: round;
              stroke-linejoin: round;
            }

            .wbi-pen-nib {
              fill: var(--wbi-accent);
              stroke: var(--fg, #20242b);
              stroke-width: 3;
            }

            .wbi-caption {
              min-height: 10cqh;
              padding-top: var(--space-1, 1.8cqh);
              color: var(--muted, #667085);
              font-family: var(--font-display, Inter, system-ui, sans-serif);
              font-size: clamp(24px, 5cqh, 52px);
              font-weight: 680;
              line-height: 1.1;
              letter-spacing: -0.02em;
              text-align: center;
              opacity: 0;
            }
          </style>

          <div
            id="wbi-clip"
            class="wbi-clip clip"
            data-start="0"
            data-duration="5"
            data-track-index="0"
          >
            <div class="wbi-stage" role="img">
              <div class="wbi-board">
                <svg
                  class="wbi-svg"
                  viewBox="0 0 1000 560"
                  preserveAspectRatio="xMidYMid meet"
                  aria-hidden="true"
                >
                  <g
                    class="wbi-sketch"
                    data-sketch="bulb"
                    transform="translate(500 280) scale(1.25 1.4) translate(-500 -256)"
                  >
                    <path
                      class="wbi-stroke"
                      d="M 430 340 C 414 310 392 286 386 244 C 376 172 427 113 501 109 C 578 105 633 160 626 235 C 622 279 596 306 574 341"
                    ></path>
                    <path
                      class="wbi-stroke wbi-accent"
                      d="M 454 238 C 469 251 482 263 499 292 C 517 261 532 247 549 235"
                    ></path>
                    <path class="wbi-stroke" d="M 431 347 C 468 353 531 350 571 343"></path>
                    <path class="wbi-stroke" d="M 438 369 C 476 376 525 373 564 365"></path>
                    <path class="wbi-stroke" d="M 454 389 C 482 403 520 402 548 385"></path>
                    <path class="wbi-stroke" d="M 333 231 C 349 228 360 230 372 232"></path>
                    <path class="wbi-stroke" d="M 640 228 C 657 225 670 226 685 230"></path>
                  </g>

                  <g
                    class="wbi-sketch"
                    data-sketch="flow"
                    transform="translate(500 280) scale(0.9 2.1) translate(-525 -265)"
                    hidden
                  >
                    <path
                      class="wbi-stroke"
                      d="M 145 205 C 145 184 160 171 184 171 L 315 171 C 338 171 351 187 351 207 L 351 322 C 351 344 337 357 314 357 L 181 357 C 158 357 145 342 145 321 Z"
                    ></path>
                    <path
                      class="wbi-stroke wbi-accent"
                      d="M 352 264 C 378 258 397 259 425 263 L 446 267 M 429 249 L 446 267 L 427 284"
                    ></path>
                    <path class="wbi-stroke" d="M 516 170 L 611 265 L 516 360 L 421 265 Z"></path>
                    <path
                      class="wbi-stroke"
                      d="M 612 265 C 641 268 662 268 691 264 L 711 263 M 694 247 L 711 263 L 694 280"
                    ></path>
                    <path
                      class="wbi-stroke"
                      d="M 711 204 C 711 184 726 171 749 171 L 868 171 C 891 171 905 187 905 208 L 905 321 C 905 343 891 357 868 357 L 748 357 C 725 357 711 342 711 321 Z"
                    ></path>
                    <path
                      class="wbi-stroke"
                      d="M 764 266 C 785 284 802 292 820 294 C 837 278 849 256 861 230"
                    ></path>
                  </g>

                  <g class="wbi-sketch" data-sketch="rocket" transform="translate(0 -17)" hidden>
                    <path
                      class="wbi-stroke"
                      d="M 500 76 C 552 117 581 184 578 272 C 576 329 549 378 500 420 C 451 378 425 329 422 272 C 419 184 448 117 500 76 Z"
                    ></path>
                    <path
                      class="wbi-stroke wbi-accent"
                      d="M 500 181 C 526 181 544 198 544 223 C 544 248 527 265 500 265 C 475 265 457 248 457 223 C 457 199 474 181 500 181 Z"
                    ></path>
                    <path
                      class="wbi-stroke"
                      d="M 430 295 C 386 320 359 363 353 419 C 389 405 420 384 448 353"
                    ></path>
                    <path
                      class="wbi-stroke"
                      d="M 570 295 C 614 320 641 363 647 419 C 611 405 580 384 552 353"
                    ></path>
                    <path
                      class="wbi-stroke"
                      d="M 476 415 C 464 445 470 478 500 518 C 530 478 536 445 524 415"
                    ></path>
                    <path class="wbi-stroke" d="M 452 431 C 433 451 427 475 433 500"></path>
                    <path class="wbi-stroke" d="M 548 431 C 567 451 573 475 567 500"></path>
                  </g>

                  <!--
                    Strokes slot. Fill this group with your own <path> elements
                    (installed copy) to replace the preset sketches; paths draw
                    in document order in the 0 0 1000 560 viewBox space. Mark a
                    path data-ink="accent" for the accent token. Ships empty.
                  -->
                  <g class="wbi-sketch" data-slot="strokes" data-sketch="custom" hidden></g>

                  <g class="wbi-pen" aria-hidden="true">
                    <g class="wbi-pen-art">
                      <path class="wbi-pen-body" d="M 0 0 L -43 -11 L -52 0 L -43 11 Z"></path>
                      <path class="wbi-pen-nib" d="M 0 0 L -11 -7 L -11 7 Z"></path>
                    </g>
                  </g>
                </svg>
              </div>
              <div class="wbi-caption"></div>
            </div>
          </div>

          <script src="https://cdn.jsdelivr.net/npm/gsap@3.14.2/dist/gsap.min.js"></script>
          <script>
            (function () {
              "use strict";

              var root = document.getElementById("root");
              var stage = root.querySelector(".wbi-stage");
              var captionElement = root.querySelector(".wbi-caption");
              var penElement = root.querySelector(".wbi-pen");
              var penArt = root.querySelector(".wbi-pen-art");
              var vars =
                window.__hyperframes && window.__hyperframes.getVariables
                  ? window.__hyperframes.getVariables()
                  : {};

              var sketchGroups = {
                bulb: root.querySelector('[data-sketch="bulb"]'),
                flow: root.querySelector('[data-sketch="flow"]'),
                rocket: root.querySelector('[data-sketch="rocket"]'),
              };
              var sketch = Object.prototype.hasOwnProperty.call(sketchGroups, vars.sketch)
                ? vars.sketch
                : "bulb";
              var caption = vars.caption == null ? "Draw the idea" : String(vars.caption);
              var penVisible = vars.pen !== "hide";
              var accentColors = {
                green: "var(--brand, #71f5a7)",
                blue: "var(--accent, #61a8ff)",
                violet: "var(--accent-2, #c5a3ff)",
              };
              var accent = Object.prototype.hasOwnProperty.call(accentColors, vars.accent)
                ? vars.accent
                : "green";
              var exitModes = { none: true, fade: true, up: true };
              var exitMode = Object.prototype.hasOwnProperty.call(exitModes, vars.exit)
                ? vars.exit
                : "none";

              // Strokes slot: user-supplied paths replace the preset sketches.
              var strokesSlot = root.querySelector('[data-slot="strokes"]');
              var slotPaths = strokesSlot ? strokesSlot.querySelectorAll("path") : [];
              var hasCustomStrokes = slotPaths.length > 0;
              if (hasCustomStrokes) {
                Array.prototype.forEach.call(slotPaths, function (path) {
                  // CSS beats SVG presentation attributes; promote an authored
                  // stroke-width to inline style so it wins over the slot rule.
                  var strokeWidth = path.getAttribute("stroke-width");
                  if (strokeWidth) path.style.strokeWidth = strokeWidth;
                });
              }

              Object.keys(sketchGroups).forEach(function (name) {
                // SVG <g> has no `hidden` IDL property (assignment is a dead
                // expando); toggle the attribute so the [hidden] CSS applies.
                if (hasCustomStrokes || name !== sketch)
                  sketchGroups[name].setAttribute("hidden", "");
                else sketchGroups[name].removeAttribute("hidden");
              });
              if (hasCustomStrokes) strokesSlot.removeAttribute("hidden");
              var activeGroup = hasCustomStrokes ? strokesSlot : sketchGroups[sketch];
              root.style.setProperty("--wbi-accent", accentColors[accent]);
              captionElement.textContent = caption;
              penElement.style.display = penVisible ? "" : "none";
              stage.setAttribute(
                "aria-label",
                (hasCustomStrokes
                  ? "Custom sketch. "
                  : sketch.charAt(0).toUpperCase() + sketch.slice(1) + " sketch. ") + caption,
              );

              var groupTransform = activeGroup.transform.baseVal.consolidate();
              var strokes = Array.from(activeGroup.querySelectorAll("path")).map(function (path) {
                var length = path.getTotalLength();
                path.style.strokeDasharray = length + " " + length;
                path.style.strokeDashoffset = String(length);
                return {
                  path: path,
                  length: length,
                  progress: 0,
                  matrix: groupTransform ? groupTransform.matrix : null,
                };
              });
              var totalLength = strokes.reduce(function (sum, stroke) {
                return sum + stroke.length;
              }, 0);

              function pointAt(stroke, distance) {
                var point = stroke.path.getPointAtLength(distance);
                return stroke.matrix ? point.matrixTransform(stroke.matrix) : point;
              }

              function pathPose(stroke, progress) {
                var distance = progress * stroke.length;
                var tangentStep = Math.max(0.5, stroke.length * 0.004);
                var before = pointAt(stroke, Math.max(0, distance - tangentStep));
                var after = pointAt(stroke, Math.min(stroke.length, distance + tangentStep));
                var point = pointAt(stroke, distance);

                return {
                  x: point.x,
                  y: point.y,
                  rotation: (Math.atan2(after.y - before.y, after.x - before.x) * 180) / Math.PI,
                };
              }

              function placePen(pose) {
                gsap.set(penElement, { x: pose.x, y: pose.y, rotation: pose.rotation });
              }

              function renderStroke(stroke) {
                var clamped = Math.max(0, Math.min(1, stroke.progress));
                stroke.path.style.strokeDashoffset = String((1 - clamped) * stroke.length);
                placePen(pathPose(stroke, clamped));
              }

              var DRAW_PHASE_BASE = 3.25;
              var CAPTION_BASE = 0.3;
              var IN_BASE = DRAW_PHASE_BASE + CAPTION_BASE;
              var OUT_BASE = exitMode === "none" ? 0 : 0.45;
              var resolvedDuration =
                window.__hyperframes && window.__hyperframes.getDuration
                  ? window.__hyperframes.getDuration()
                  : undefined;
              var duration = Math.max(
                0.001,
                typeof resolvedDuration === "number"
                  ? resolvedDuration
                  : parseFloat(root.dataset.duration || "5"),
              );
              var fixedTotal = IN_BASE + OUT_BASE;
              var phaseScale = duration < fixedTotal ? duration / fixedTotal : 1;
              var IN = IN_BASE * phaseScale;
              var OUT = OUT_BASE * phaseScale;
              var HOLD = Math.max(0, duration - IN - OUT);
              var DRAW_PHASE = DRAW_PHASE_BASE * phaseScale;
              var CAPTION = CAPTION_BASE * phaseScale;
              var hopCount = strokes.length - 1;
              var HOP = 0.1 * phaseScale;
              var MIN_DRAW = 0.26 * phaseScale;
              // Custom slots can hold many strokes; when the fixed per-stroke
              // floors alone would overrun the draw phase, shrink them together
              // so the cadence stays sequential and the phase never overflows.
              var fixedNeed = MIN_DRAW * strokes.length + HOP * hopCount;
              if (fixedNeed > DRAW_PHASE) {
                var crowd = DRAW_PHASE / fixedNeed;
                HOP *= crowd;
                MIN_DRAW *= crowd;
              }
              var DRAW_BUDGET = DRAW_PHASE - HOP * hopCount;
              var LENGTH_BUDGET = Math.max(0, DRAW_BUDGET - MIN_DRAW * strokes.length);
              var OUT_START = IN + HOLD;
              var cursor = 0;

              gsap.set(stage, { opacity: 0, y: "1.2cqh" });
              gsap.set(captionElement, { opacity: 0, y: "1.4cqh" });
              gsap.set(penElement, { opacity: penVisible ? 1 : 0 });
              gsap.set(penArt, { y: 0, transformOrigin: "0px 0px" });
              placePen(pathPose(strokes[0], 0));

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

              // IN: each stroke owns one progress value. Its single onUpdate
              // paints the dash and places the nib at the same ink front.
              tl.to(
                stage,
                { opacity: 1, y: "0cqh", duration: Math.min(0.26, IN), ease: "power2.out" },
                0,
              );

              strokes.forEach(function (stroke, index) {
                var drawDuration = MIN_DRAW + (LENGTH_BUDGET * stroke.length) / totalLength;

                tl.to(
                  stroke,
                  {
                    progress: 1,
                    duration: drawDuration,
                    ease: "power1.inOut",
                    onUpdate: function () {
                      renderStroke(stroke);
                    },
                  },
                  cursor,
                );
                cursor += drawDuration;

                if (index < strokes.length - 1) {
                  var nextStroke = strokes[index + 1];
                  var fromPose = pathPose(stroke, 1);
                  var toPose = pathPose(nextStroke, 0);
                  var hopState = { progress: 0 };

                  tl.to(
                    hopState,
                    {
                      progress: 1,
                      duration: HOP,
                      ease: "power2.out",
                      onUpdate: function () {
                        var progress = hopState.progress;
                        placePen({
                          x: fromPose.x + (toPose.x - fromPose.x) * progress,
                          y:
                            fromPose.y +
                            (toPose.y - fromPose.y) * progress -
                            Math.sin(Math.PI * progress) * 18,
                          rotation:
                            fromPose.rotation + (toPose.rotation - fromPose.rotation) * progress,
                        });
                        gsap.set(penArt, { y: -Math.sin(Math.PI * progress) * 8 });
                      },
                    },
                    cursor,
                  );
                  cursor += HOP;
                }
              });

              tl.to(
                captionElement,
                { opacity: 1, y: "0cqh", duration: CAPTION, ease: "power2.out" },
                cursor,
              );
              tl.to(penElement, { opacity: 0, duration: CAPTION, ease: "power2.out" }, cursor);
              tl.to(penArt, { y: -18, duration: CAPTION, ease: "power2.out" }, cursor);

              // HOLD: the completed lockup stays dead calm. Duration changes
              // stretch only this gap between the caption reveal and OUT.

              // OUT: only when an exit is requested; exit none holds the final
              // frame to the end (frame roots own transitions).
              if (exitMode !== "none") {
                var exitTween = { opacity: 0, duration: OUT, ease: "power2.in" };
                if (exitMode === "up") exitTween.y = "-1.8cqh";
                tl.to(stage, exitTween, OUT_START);
              }

              tl.seek(0);
              window.__timelines = window.__timelines || {};
              window.__timelines["whiteboard-ink"] = tl;
            })();
          </script>
        </div>
      </template>
    </body>
  </html>
  ```
</Accordion>

Tagged `motion-primitive` `intro` `reveal` `svg` `whiteboard` `line-draw` `slot`.

## Related topics

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