> ## 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.

# Camera Scan Gate

> A camera and QR recognition moment with a viewfinder sweep, bracket lock, confirmation pulse, and verified next beat.

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/camera-scan-gate.json" compositionId="camera-scan-gate" compositionSrc="compositions/components/camera-scan-gate.html" variables={[{"id":"scanColor","type":"string","role":"style","label":"Scan color","description":"Any CSS color value used by the scan line and recognition glow.","default":"var(--brand)"},{"id":"targetLabel","type":"string","role":"content","label":"Target label","description":"Confirmation label revealed at recognition lock. Blank hides the line.","default":"Verified"},{"id":"sweepSpeed","type":"number","role":"timing","label":"Sweep speed","description":"Speed multiplier for the scan sweep phase only.","default":1,"min":0.8,"max":1.6,"step":0.1,"unit":"x"}]}>
  ```html camera-scan-gate.html theme={null}
  <!doctype html>
  <!--
    camera-scan-gate -- HyperFrames video primitive (ui-props / interaction / demonstrate)

    Concept: a camera viewfinder scans once, tightens its four L-shaped corner
    brackets onto a detected target, then confirms recognition with a pulse,
    check flash, and target label. One mechanic, one job: demonstrate the causal
    scan -> lock -> confirmation gate that unlocks a product's next beat.

    Compiled-from evidence: SIM fixture; MOBILE mobile-inventory (scan-to-onboard
    and scan-to-pay moments in the video-primitives candidates card).

    Use when: a mobile product scene needs a camera, QR, identity, or payment
    recognition moment whose successful lock causes the following action. Skip
    it for passive camera decoration or a generic loading state.

    Variables (declared in data-composition-variables below):
      - scanColor (string, default "var(--brand)"): any CSS color value used by
        the scan line, lock brackets, and confirmation glow.
      - targetLabel (string, default "Verified"): label revealed at lock. Empty
        string hides the label line entirely.
      - sweepSpeed (number, default 1, range 0.8 to 1.6): scan sweep speed only.
        It changes the sweep start while its landing sync point stays fixed.

    Envelope (fixed IN/OUT, elastic HOLD only, never gsap.timeScale()):
      IN_BASE  = 1.05s  stage settles, sweep lands, then recognition locks
      HOLD     = elastic = max(0, D - (IN_BASE + OUT_BASE)); a faint finite
                 frame glow breathes, or remains still when HOLD == 0
      OUT_BASE = 0.50s  resolved gate releases with a short fade
      If D < IN_BASE + OUT_BASE, IN and OUT scale down together so IN + OUT == D
      and HOLD == 0.

    Sync points (fixed offsets into IN, never inside elastic HOLD):
      - scan-landed: 0.50s into unscaled IN, the --ease-standard sweep completes
      - recognition-lock: 0.68s into unscaled IN, brackets tighten with
        --ease-overshoot while confirmation and the target label fire
      Both offsets scale proportionally only when the full envelope compresses.

    Sound cue: a soft recognition chime fires at recognition-lock. The primitive
    never plays audio itself. It dispatches an `hf:sfx` CustomEvent
    ({ id: "lock-chime", t: LOCK_AT }) for the host mix stage to route.

    Mount contract: this file is a MOUNTABLE SUB-COMPOSITION, not a standalone
    composition. A host loads it via data-composition-src; the runtime clones
    only <template> contents, so all live style, markup, and script stays inside
    the template. The root has no data-width/data-height and fills the host box
    with position:absolute, inset:0, and container-type:size. It is styled by
    #root because mounted CSS scoping would stop a root-class selector from
    matching the root itself. The hardcoded "camera-scan-gate" composition id
    is required because the mounted flattening step strips data-composition-id
    before this script registers its timeline. Variables are read through
    window.__hyperframes.getVariables(), which owns declared defaults merged
    with per-instance host overrides after mounting.
  -->
  <html
    lang="en"
    data-composition-variables='[
      { "id": "scanColor", "type": "string", "role": "style", "label": "Scan color", "description": "Any CSS color value used by the scan line and recognition glow.", "default": "var(--brand)" },
      { "id": "targetLabel", "type": "string", "role": "content", "label": "Target label", "description": "Confirmation label revealed at recognition lock. Blank hides the line.", "default": "Verified" },
      { "id": "sweepSpeed", "type": "number", "role": "timing", "label": "Sweep speed", "description": "Speed multiplier for the scan sweep phase only.", "default": 1, "min": 0.8, "max": 1.6, "step": 0.1, "unit": "x" }
    ]'
  >
    <head>
      <meta charset="UTF-8" />
      <title>Camera Scan Gate</title>
      <!-- Metadata only. The loader reads variable declarations from this html
           element, while the mount runtime discards everything outside the
           template. -->
    </head>
    <body>
      <template>
        <div
          id="root"
          data-composition-id="camera-scan-gate"
          data-start="0"
          data-duration="4"
          data-fps="30"
        >
          <style>
            *,
            *::before,
            *::after {
              box-sizing: border-box;
            }

            /* INVARIANT: the host owns dimensions. #root fills that box and
               establishes the cqw/cqh basis for every visible measurement. */
            #root {
              position: absolute;
              inset: 0;
              container-type: size;
              isolation: isolate;
              overflow: hidden;
              color: var(--fg, #f8fafc);
              font-family: var(--font-body, Inter, system-ui, sans-serif);
            }

            .csg-clip {
              position: relative;
              width: 100%;
              height: 100%;
              display: grid;
              place-items: center;
              overflow: hidden;
              background: var(--bg, #0b1120);
            }

            .csg-stage {
              position: relative;
              width: min(64cqw, 76cqh);
              aspect-ratio: 1;
              opacity: 0;
            }

            /* EDIT ZONE: the outer viewfinder is a square so one centered scale
               operation tightens all four brackets onto the target equally. */
            .csg-frame,
            .csg-corner-layer,
            .csg-scan-window {
              position: absolute;
              inset: 0;
            }

            .csg-frame {
              border: 0.16cqw solid color-mix(in srgb, var(--border, #334155) 74%, transparent);
              border-radius: var(--space-2, 2.4cqw);
              background: color-mix(in srgb, var(--surface, #1e293b) 34%, transparent);
              box-shadow: inset 0 0 5cqw color-mix(in srgb, var(--bg, #0b1120) 60%, transparent);
            }

            .csg-grid {
              position: absolute;
              inset: 0;
              border-radius: inherit;
              background-image:
                linear-gradient(
                  to right,
                  transparent 33%,
                  color-mix(in srgb, var(--border, #334155) 32%, transparent) 33% 33.25%,
                  transparent 33.25% 66.5%,
                  color-mix(in srgb, var(--border, #334155) 32%, transparent) 66.5% 66.75%,
                  transparent 66.75%
                ),
                linear-gradient(
                  to bottom,
                  transparent 33%,
                  color-mix(in srgb, var(--border, #334155) 32%, transparent) 33% 33.25%,
                  transparent 33.25% 66.5%,
                  color-mix(in srgb, var(--border, #334155) 32%, transparent) 66.5% 66.75%,
                  transparent 66.75%
                );
              opacity: 0.55;
            }

            .csg-ambient {
              position: absolute;
              inset: -4%;
              border: 0.45cqw solid
                color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 48%, transparent);
              border-radius: var(--space-3, 3.2cqw);
              box-shadow: 0 0 4.5cqw
                color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 38%, transparent);
              opacity: 0;
            }

            .csg-corner-layer {
              transform-origin: center;
              z-index: 3;
            }

            .csg-corner {
              position: absolute;
              width: 18%;
              height: 18%;
              border-color: var(--csg-scan-color, var(--brand, #22c55e));
              border-style: solid;
              filter: drop-shadow(
                0 0 0.9cqw
                  color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 56%, transparent)
              );
            }

            .csg-corner-tl {
              top: 0;
              left: 0;
              border-width: 0.65cqw 0 0 0.65cqw;
              border-radius: var(--space-2, 2.4cqw) 0 0;
            }

            .csg-corner-tr {
              top: 0;
              right: 0;
              border-width: 0.65cqw 0.65cqw 0 0;
              border-radius: 0 var(--space-2, 2.4cqw) 0 0;
            }

            .csg-corner-br {
              right: 0;
              bottom: 0;
              border-width: 0 0.65cqw 0.65cqw 0;
              border-radius: 0 0 var(--space-2, 2.4cqw);
            }

            .csg-corner-bl {
              bottom: 0;
              left: 0;
              border-width: 0 0 0.65cqw 0.65cqw;
              border-radius: 0 0 0 var(--space-2, 2.4cqw);
            }

            .csg-scan-window {
              z-index: 2;
              inset: 3.5%;
              overflow: hidden;
            }

            .csg-sweep {
              position: absolute;
              inset: 0;
              width: 100%;
              height: 100%;
            }

            .csg-scan-line {
              position: absolute;
              inset: 0 0 auto;
              width: 100%;
              height: 0.38cqh;
              border-radius: 999cqw;
              background: var(--csg-scan-color, var(--brand, #22c55e));
              box-shadow:
                0 0 1.2cqw var(--csg-scan-color, var(--brand, #22c55e)),
                0 1.8cqh 3.6cqh
                  color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 42%, transparent);
            }

            .csg-target {
              position: absolute;
              z-index: 1;
              width: 60%;
              height: 60%;
              top: 20%;
              left: 20%;
              border: 0.2cqw solid
                color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 65%, transparent);
              border-radius: var(--space-2, 2.4cqw);
              background: color-mix(
                in srgb,
                var(--csg-scan-color, var(--brand, #22c55e)) 7%,
                transparent
              );
              opacity: 0;
            }

            .csg-confirmation {
              position: absolute;
              z-index: 4;
              inset: 0;
              display: flex;
              flex-direction: column;
              align-items: center;
              justify-content: center;
              gap: var(--space-2, 2.2cqh);
            }

            .csg-pulse {
              position: absolute;
              width: 30%;
              aspect-ratio: 1;
              border: 0.42cqw solid var(--csg-scan-color, var(--brand, #22c55e));
              border-radius: 50%;
              box-shadow: 0 0 4.5cqw
                color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 58%, transparent);
              opacity: 0;
            }

            .csg-check {
              display: block;
              width: 8.5%;
              height: 15%;
              margin-top: -5%;
              border-right: 0.8cqw solid var(--csg-scan-color, var(--brand, #22c55e));
              border-bottom: 0.8cqw solid var(--csg-scan-color, var(--brand, #22c55e));
              filter: drop-shadow(
                0 0 1.1cqw
                  color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 65%, transparent)
              );
              opacity: 0;
              transform: rotate(45deg);
            }

            .csg-label {
              min-width: 34%;
              padding: var(--space-1, 1cqh) var(--space-3, 3cqw);
              border: 0.14cqw solid
                color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 48%, transparent);
              border-radius: 999cqw;
              background: color-mix(in srgb, var(--surface, #1e293b) 88%, transparent);
              color: var(--fg, #f8fafc);
              font-family: var(--font-display, Inter, system-ui, sans-serif);
              font-size: clamp(2cqh, 2.8cqw, 3.3cqh);
              font-weight: 760;
              letter-spacing: 0.035em;
              line-height: 1.1;
              text-align: center;
              opacity: 0;
            }

            .csg-label:empty {
              display: none;
            }
          </style>

          <div
            id="camera-scan-gate-clip"
            class="csg-clip clip"
            data-start="0"
            data-duration="4"
            data-track-index="0"
          >
            <div class="csg-stage" role="img" aria-label="Camera recognition scanner">
              <div class="csg-frame">
                <div class="csg-grid" aria-hidden="true"></div>
              </div>
              <div class="csg-ambient" aria-hidden="true"></div>
              <div class="csg-target" aria-hidden="true"></div>
              <div class="csg-scan-window" aria-hidden="true">
                <div class="csg-sweep">
                  <div class="csg-scan-line"></div>
                </div>
              </div>
              <div class="csg-corner-layer" aria-hidden="true">
                <span class="csg-corner csg-corner-tl"></span>
                <span class="csg-corner csg-corner-tr"></span>
                <span class="csg-corner csg-corner-br"></span>
                <span class="csg-corner csg-corner-bl"></span>
              </div>
              <div class="csg-confirmation">
                <span class="csg-pulse" aria-hidden="true"></span>
                <span class="csg-check" aria-hidden="true"></span>
                <span class="csg-label"></span>
              </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");
              // Literal, not read from the DOM. Mounted flattening strips the
              // root's data-composition-id before timeline registration.
              var compositionId = "camera-scan-gate";
              var stage = root.querySelector(".csg-stage");
              var cornerLayer = root.querySelector(".csg-corner-layer");
              var sweep = root.querySelector(".csg-sweep");
              var target = root.querySelector(".csg-target");
              var ambient = root.querySelector(".csg-ambient");
              var pulse = root.querySelector(".csg-pulse");
              var check = root.querySelector(".csg-check");
              var label = root.querySelector(".csg-label");

              // EDIT ZONE: declared defaults and per-instance overrides have one
              // owner after mount, window.__hyperframes.getVariables().
              var vars =
                window.__hyperframes && window.__hyperframes.getVariables
                  ? window.__hyperframes.getVariables()
                  : {};
              var scanColor =
                vars.scanColor == null || String(vars.scanColor).trim() === ""
                  ? "var(--brand)"
                  : String(vars.scanColor);
              var targetLabel = vars.targetLabel == null ? "" : String(vars.targetLabel);
              var rawSweepSpeed = Number(vars.sweepSpeed);
              // INVARIANT: sweep speed is finite and clamped to the declared
              // 0.8 to 1.6 range. It never changes IN, HOLD, OUT, or sync points.
              var sweepSpeed = Number.isFinite(rawSweepSpeed)
                ? Math.max(0.8, Math.min(1.6, rawSweepSpeed))
                : 1;

              root.style.setProperty("--csg-scan-color", scanColor);
              label.textContent = targetLabel;

              var beatValue = parseFloat(getComputedStyle(root).getPropertyValue("--dur-beat"));
              var beat = Number.isFinite(beatValue) && beatValue > 0 ? beatValue : 0.5;
              var AMBIENT_HALF = beat * 1.5;

              // RETIME RANGE: IN_BASE and OUT_BASE own the interaction envelope.
              // The only elastic phase is HOLD. Short durations scale IN and OUT
              // together with one factor, never gsap.timeScale().
              var IN_BASE = 1.05;
              var OUT_BASE = 0.5;
              var STAGE_IN_BASE = 0.28;
              var SWEEP_DURATION_BASE = 0.4;
              var SWEEP_LANDS_BASE = 0.5;
              var LOCK_AT_BASE = 0.68;
              var LOCK_DURATION_BASE = 0.22;
              var CONFIRM_DURATION_BASE = 0.2;
              var PULSE_HALF_BASE = 0.18;

              var duration = Math.max(0.001, parseFloat(root.dataset.duration || "4"));
              var totalBase = IN_BASE + OUT_BASE;
              var scale = duration < totalBase ? duration / totalBase : 1;
              var IN = IN_BASE * scale;
              var OUT = OUT_BASE * scale;
              var STAGE_IN = STAGE_IN_BASE * scale;
              var SWEEP_LANDS = SWEEP_LANDS_BASE * scale;
              var SWEEP_DURATION = (SWEEP_DURATION_BASE / sweepSpeed) * scale;
              var SWEEP_START = Math.max(0, SWEEP_LANDS - SWEEP_DURATION);
              var LOCK_AT = LOCK_AT_BASE * scale;
              var LOCK_DURATION = LOCK_DURATION_BASE * scale;
              var CONFIRM_DURATION = CONFIRM_DURATION_BASE * scale;
              var PULSE_HALF = PULSE_HALF_BASE * scale;
              var HOLD = Math.max(0, duration - (IN + OUT));
              var HOLD_START = IN;
              var OUT_START = IN + HOLD;

              function fireSfx(id, t) {
                root.dispatchEvent(
                  new CustomEvent("hf:sfx", { detail: { id: id, t: t }, bubbles: true }),
                );
              }

              // Explicit both-endpoints state before timeline construction keeps
              // direct seek to t=0 correct without playing through prior frames.
              gsap.set(stage, { opacity: 0, scale: 0.94 });
              gsap.set(cornerLayer, { scale: 1 });
              gsap.set(sweep, { opacity: 1, yPercent: 0 });
              gsap.set(target, { opacity: 0, scale: 0.96 });
              gsap.set(ambient, { opacity: 0, scale: 1 });
              gsap.set(pulse, { opacity: 0, scale: 0.9 });
              gsap.set(check, { opacity: 0, scale: 0.94 });
              gsap.set(label, { opacity: 0, y: "1.2cqh", scale: 0.96 });

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

              // IN: settle, scan, then lock. The sweep uses --ease-standard's
              // GSAP equivalent and lands at a fixed offset inside IN.
              tl.to(stage, { opacity: 1, scale: 1, duration: STAGE_IN, ease: "power2.out" }, 0);
              tl.to(
                sweep,
                { yPercent: 100, duration: SWEEP_DURATION, ease: "power2.out" },
                SWEEP_START,
              );
              tl.set(sweep, { opacity: 0 }, SWEEP_LANDS);

              // recognition-lock is the single causal gate. Corner tightening is
              // the one moderate --ease-overshoot motion in this primitive.
              tl.to(
                cornerLayer,
                { scale: 0.6, duration: LOCK_DURATION, ease: "back.out(1.7)" },
                LOCK_AT,
              );
              tl.to(
                target,
                { opacity: 1, scale: 1, duration: CONFIRM_DURATION, ease: "power2.out" },
                LOCK_AT,
              );
              tl.to(
                check,
                { opacity: 1, scale: 1, duration: CONFIRM_DURATION, ease: "power2.out" },
                LOCK_AT,
              );
              tl.to(
                label,
                { opacity: 1, y: 0, scale: 1, duration: CONFIRM_DURATION, ease: "power2.out" },
                LOCK_AT,
              );
              tl.to(
                pulse,
                {
                  opacity: 0.9,
                  scale: 1.25,
                  duration: PULSE_HALF,
                  ease: "power2.out",
                  yoyo: true,
                  repeat: 1,
                },
                LOCK_AT,
              );
              // Side-effect invariant: this timeline callback is the only actor
              // that emits lock-chime, once at the recognition-lock sync point.
              tl.call(
                function () {
                  fireSfx("lock-chime", LOCK_AT);
                },
                [],
                LOCK_AT,
              );

              // HOLD: a separate layer breathes with a finite repeat count, so
              // the resolved gate stays alive without competing with lock tweens.
              if (HOLD > AMBIENT_HALF) {
                var ambientRepeat = Math.max(0, Math.floor(HOLD / AMBIENT_HALF) - 1);
                tl.to(
                  ambient,
                  {
                    opacity: 0.3,
                    scale: 1.015,
                    duration: AMBIENT_HALF,
                    ease: "sine.inOut",
                    yoyo: true,
                    repeat: ambientRepeat,
                  },
                  HOLD_START,
                );
              }

              // OUT: asymmetric release. HOLD alone absorbs duration changes.
              tl.to(stage, { opacity: 0, scale: 0.98, duration: OUT, ease: "power2.in" }, OUT_START);

              tl.seek(0);

              window.__timelines = window.__timelines || {};
              window.__timelines[compositionId] = tl;
            })();
          </script>
        </div>
      </template>
    </body>
  </html>
  ```
</VariablesExplorer>

## Install

<InstallCommand command="npx hyperframes add camera-scan-gate" item="camera-scan-gate" />

That writes one file: `compositions/components/camera-scan-gate.html`.

## Paste it into your composition

Open `compositions/components/camera-scan-gate.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                                                           |
| ------------- | -------------- | ----------------------- | ---------------------------------------------------------------------- |
| `scanColor`   | `var(--brand)` | string                  | Any CSS color value used by the scan line and recognition glow.        |
| `targetLabel` | `Verified`     | string                  | Confirmation label revealed at recognition lock. Blank hides the line. |
| `sweepSpeed`  | `1`            | 0.8x to 1.6x, step 0.1x | Speed multiplier for the scan sweep phase only.                        |

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="camera-scan-gate"
  data-composition-src="compositions/components/camera-scan-gate.html"
  data-variable-values='{"scanColor":"var(--brand)","targetLabel":"Verified","sweepSpeed":1}'
></div>
```

## Source

<Accordion title={`camera-scan-gate.html`}>
  ```html theme={null}
  <!doctype html>
  <!--
    camera-scan-gate -- HyperFrames video primitive (ui-props / interaction / demonstrate)

    Concept: a camera viewfinder scans once, tightens its four L-shaped corner
    brackets onto a detected target, then confirms recognition with a pulse,
    check flash, and target label. One mechanic, one job: demonstrate the causal
    scan -> lock -> confirmation gate that unlocks a product's next beat.

    Compiled-from evidence: SIM fixture; MOBILE mobile-inventory (scan-to-onboard
    and scan-to-pay moments in the video-primitives candidates card).

    Use when: a mobile product scene needs a camera, QR, identity, or payment
    recognition moment whose successful lock causes the following action. Skip
    it for passive camera decoration or a generic loading state.

    Variables (declared in data-composition-variables below):
      - scanColor (string, default "var(--brand)"): any CSS color value used by
        the scan line, lock brackets, and confirmation glow.
      - targetLabel (string, default "Verified"): label revealed at lock. Empty
        string hides the label line entirely.
      - sweepSpeed (number, default 1, range 0.8 to 1.6): scan sweep speed only.
        It changes the sweep start while its landing sync point stays fixed.

    Envelope (fixed IN/OUT, elastic HOLD only, never gsap.timeScale()):
      IN_BASE  = 1.05s  stage settles, sweep lands, then recognition locks
      HOLD     = elastic = max(0, D - (IN_BASE + OUT_BASE)); a faint finite
                 frame glow breathes, or remains still when HOLD == 0
      OUT_BASE = 0.50s  resolved gate releases with a short fade
      If D < IN_BASE + OUT_BASE, IN and OUT scale down together so IN + OUT == D
      and HOLD == 0.

    Sync points (fixed offsets into IN, never inside elastic HOLD):
      - scan-landed: 0.50s into unscaled IN, the --ease-standard sweep completes
      - recognition-lock: 0.68s into unscaled IN, brackets tighten with
        --ease-overshoot while confirmation and the target label fire
      Both offsets scale proportionally only when the full envelope compresses.

    Sound cue: a soft recognition chime fires at recognition-lock. The primitive
    never plays audio itself. It dispatches an `hf:sfx` CustomEvent
    ({ id: "lock-chime", t: LOCK_AT }) for the host mix stage to route.

    Mount contract: this file is a MOUNTABLE SUB-COMPOSITION, not a standalone
    composition. A host loads it via data-composition-src; the runtime clones
    only <template> contents, so all live style, markup, and script stays inside
    the template. The root has no data-width/data-height and fills the host box
    with position:absolute, inset:0, and container-type:size. It is styled by
    #root because mounted CSS scoping would stop a root-class selector from
    matching the root itself. The hardcoded "camera-scan-gate" composition id
    is required because the mounted flattening step strips data-composition-id
    before this script registers its timeline. Variables are read through
    window.__hyperframes.getVariables(), which owns declared defaults merged
    with per-instance host overrides after mounting.
  -->
  <html
    lang="en"
    data-composition-variables='[
      { "id": "scanColor", "type": "string", "role": "style", "label": "Scan color", "description": "Any CSS color value used by the scan line and recognition glow.", "default": "var(--brand)" },
      { "id": "targetLabel", "type": "string", "role": "content", "label": "Target label", "description": "Confirmation label revealed at recognition lock. Blank hides the line.", "default": "Verified" },
      { "id": "sweepSpeed", "type": "number", "role": "timing", "label": "Sweep speed", "description": "Speed multiplier for the scan sweep phase only.", "default": 1, "min": 0.8, "max": 1.6, "step": 0.1, "unit": "x" }
    ]'
  >
    <head>
      <meta charset="UTF-8" />
      <title>Camera Scan Gate</title>
      <!-- Metadata only. The loader reads variable declarations from this html
           element, while the mount runtime discards everything outside the
           template. -->
    </head>
    <body>
      <template>
        <div
          id="root"
          data-composition-id="camera-scan-gate"
          data-start="0"
          data-duration="4"
          data-fps="30"
        >
          <style>
            *,
            *::before,
            *::after {
              box-sizing: border-box;
            }

            /* INVARIANT: the host owns dimensions. #root fills that box and
               establishes the cqw/cqh basis for every visible measurement. */
            #root {
              position: absolute;
              inset: 0;
              container-type: size;
              isolation: isolate;
              overflow: hidden;
              color: var(--fg, #f8fafc);
              font-family: var(--font-body, Inter, system-ui, sans-serif);
            }

            .csg-clip {
              position: relative;
              width: 100%;
              height: 100%;
              display: grid;
              place-items: center;
              overflow: hidden;
              background: var(--bg, #0b1120);
            }

            .csg-stage {
              position: relative;
              width: min(64cqw, 76cqh);
              aspect-ratio: 1;
              opacity: 0;
            }

            /* EDIT ZONE: the outer viewfinder is a square so one centered scale
               operation tightens all four brackets onto the target equally. */
            .csg-frame,
            .csg-corner-layer,
            .csg-scan-window {
              position: absolute;
              inset: 0;
            }

            .csg-frame {
              border: 0.16cqw solid color-mix(in srgb, var(--border, #334155) 74%, transparent);
              border-radius: var(--space-2, 2.4cqw);
              background: color-mix(in srgb, var(--surface, #1e293b) 34%, transparent);
              box-shadow: inset 0 0 5cqw color-mix(in srgb, var(--bg, #0b1120) 60%, transparent);
            }

            .csg-grid {
              position: absolute;
              inset: 0;
              border-radius: inherit;
              background-image:
                linear-gradient(
                  to right,
                  transparent 33%,
                  color-mix(in srgb, var(--border, #334155) 32%, transparent) 33% 33.25%,
                  transparent 33.25% 66.5%,
                  color-mix(in srgb, var(--border, #334155) 32%, transparent) 66.5% 66.75%,
                  transparent 66.75%
                ),
                linear-gradient(
                  to bottom,
                  transparent 33%,
                  color-mix(in srgb, var(--border, #334155) 32%, transparent) 33% 33.25%,
                  transparent 33.25% 66.5%,
                  color-mix(in srgb, var(--border, #334155) 32%, transparent) 66.5% 66.75%,
                  transparent 66.75%
                );
              opacity: 0.55;
            }

            .csg-ambient {
              position: absolute;
              inset: -4%;
              border: 0.45cqw solid
                color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 48%, transparent);
              border-radius: var(--space-3, 3.2cqw);
              box-shadow: 0 0 4.5cqw
                color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 38%, transparent);
              opacity: 0;
            }

            .csg-corner-layer {
              transform-origin: center;
              z-index: 3;
            }

            .csg-corner {
              position: absolute;
              width: 18%;
              height: 18%;
              border-color: var(--csg-scan-color, var(--brand, #22c55e));
              border-style: solid;
              filter: drop-shadow(
                0 0 0.9cqw
                  color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 56%, transparent)
              );
            }

            .csg-corner-tl {
              top: 0;
              left: 0;
              border-width: 0.65cqw 0 0 0.65cqw;
              border-radius: var(--space-2, 2.4cqw) 0 0;
            }

            .csg-corner-tr {
              top: 0;
              right: 0;
              border-width: 0.65cqw 0.65cqw 0 0;
              border-radius: 0 var(--space-2, 2.4cqw) 0 0;
            }

            .csg-corner-br {
              right: 0;
              bottom: 0;
              border-width: 0 0.65cqw 0.65cqw 0;
              border-radius: 0 0 var(--space-2, 2.4cqw);
            }

            .csg-corner-bl {
              bottom: 0;
              left: 0;
              border-width: 0 0 0.65cqw 0.65cqw;
              border-radius: 0 0 0 var(--space-2, 2.4cqw);
            }

            .csg-scan-window {
              z-index: 2;
              inset: 3.5%;
              overflow: hidden;
            }

            .csg-sweep {
              position: absolute;
              inset: 0;
              width: 100%;
              height: 100%;
            }

            .csg-scan-line {
              position: absolute;
              inset: 0 0 auto;
              width: 100%;
              height: 0.38cqh;
              border-radius: 999cqw;
              background: var(--csg-scan-color, var(--brand, #22c55e));
              box-shadow:
                0 0 1.2cqw var(--csg-scan-color, var(--brand, #22c55e)),
                0 1.8cqh 3.6cqh
                  color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 42%, transparent);
            }

            .csg-target {
              position: absolute;
              z-index: 1;
              width: 60%;
              height: 60%;
              top: 20%;
              left: 20%;
              border: 0.2cqw solid
                color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 65%, transparent);
              border-radius: var(--space-2, 2.4cqw);
              background: color-mix(
                in srgb,
                var(--csg-scan-color, var(--brand, #22c55e)) 7%,
                transparent
              );
              opacity: 0;
            }

            .csg-confirmation {
              position: absolute;
              z-index: 4;
              inset: 0;
              display: flex;
              flex-direction: column;
              align-items: center;
              justify-content: center;
              gap: var(--space-2, 2.2cqh);
            }

            .csg-pulse {
              position: absolute;
              width: 30%;
              aspect-ratio: 1;
              border: 0.42cqw solid var(--csg-scan-color, var(--brand, #22c55e));
              border-radius: 50%;
              box-shadow: 0 0 4.5cqw
                color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 58%, transparent);
              opacity: 0;
            }

            .csg-check {
              display: block;
              width: 8.5%;
              height: 15%;
              margin-top: -5%;
              border-right: 0.8cqw solid var(--csg-scan-color, var(--brand, #22c55e));
              border-bottom: 0.8cqw solid var(--csg-scan-color, var(--brand, #22c55e));
              filter: drop-shadow(
                0 0 1.1cqw
                  color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 65%, transparent)
              );
              opacity: 0;
              transform: rotate(45deg);
            }

            .csg-label {
              min-width: 34%;
              padding: var(--space-1, 1cqh) var(--space-3, 3cqw);
              border: 0.14cqw solid
                color-mix(in srgb, var(--csg-scan-color, var(--brand, #22c55e)) 48%, transparent);
              border-radius: 999cqw;
              background: color-mix(in srgb, var(--surface, #1e293b) 88%, transparent);
              color: var(--fg, #f8fafc);
              font-family: var(--font-display, Inter, system-ui, sans-serif);
              font-size: clamp(2cqh, 2.8cqw, 3.3cqh);
              font-weight: 760;
              letter-spacing: 0.035em;
              line-height: 1.1;
              text-align: center;
              opacity: 0;
            }

            .csg-label:empty {
              display: none;
            }
          </style>

          <div
            id="camera-scan-gate-clip"
            class="csg-clip clip"
            data-start="0"
            data-duration="4"
            data-track-index="0"
          >
            <div class="csg-stage" role="img" aria-label="Camera recognition scanner">
              <div class="csg-frame">
                <div class="csg-grid" aria-hidden="true"></div>
              </div>
              <div class="csg-ambient" aria-hidden="true"></div>
              <div class="csg-target" aria-hidden="true"></div>
              <div class="csg-scan-window" aria-hidden="true">
                <div class="csg-sweep">
                  <div class="csg-scan-line"></div>
                </div>
              </div>
              <div class="csg-corner-layer" aria-hidden="true">
                <span class="csg-corner csg-corner-tl"></span>
                <span class="csg-corner csg-corner-tr"></span>
                <span class="csg-corner csg-corner-br"></span>
                <span class="csg-corner csg-corner-bl"></span>
              </div>
              <div class="csg-confirmation">
                <span class="csg-pulse" aria-hidden="true"></span>
                <span class="csg-check" aria-hidden="true"></span>
                <span class="csg-label"></span>
              </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");
              // Literal, not read from the DOM. Mounted flattening strips the
              // root's data-composition-id before timeline registration.
              var compositionId = "camera-scan-gate";
              var stage = root.querySelector(".csg-stage");
              var cornerLayer = root.querySelector(".csg-corner-layer");
              var sweep = root.querySelector(".csg-sweep");
              var target = root.querySelector(".csg-target");
              var ambient = root.querySelector(".csg-ambient");
              var pulse = root.querySelector(".csg-pulse");
              var check = root.querySelector(".csg-check");
              var label = root.querySelector(".csg-label");

              // EDIT ZONE: declared defaults and per-instance overrides have one
              // owner after mount, window.__hyperframes.getVariables().
              var vars =
                window.__hyperframes && window.__hyperframes.getVariables
                  ? window.__hyperframes.getVariables()
                  : {};
              var scanColor =
                vars.scanColor == null || String(vars.scanColor).trim() === ""
                  ? "var(--brand)"
                  : String(vars.scanColor);
              var targetLabel = vars.targetLabel == null ? "" : String(vars.targetLabel);
              var rawSweepSpeed = Number(vars.sweepSpeed);
              // INVARIANT: sweep speed is finite and clamped to the declared
              // 0.8 to 1.6 range. It never changes IN, HOLD, OUT, or sync points.
              var sweepSpeed = Number.isFinite(rawSweepSpeed)
                ? Math.max(0.8, Math.min(1.6, rawSweepSpeed))
                : 1;

              root.style.setProperty("--csg-scan-color", scanColor);
              label.textContent = targetLabel;

              var beatValue = parseFloat(getComputedStyle(root).getPropertyValue("--dur-beat"));
              var beat = Number.isFinite(beatValue) && beatValue > 0 ? beatValue : 0.5;
              var AMBIENT_HALF = beat * 1.5;

              // RETIME RANGE: IN_BASE and OUT_BASE own the interaction envelope.
              // The only elastic phase is HOLD. Short durations scale IN and OUT
              // together with one factor, never gsap.timeScale().
              var IN_BASE = 1.05;
              var OUT_BASE = 0.5;
              var STAGE_IN_BASE = 0.28;
              var SWEEP_DURATION_BASE = 0.4;
              var SWEEP_LANDS_BASE = 0.5;
              var LOCK_AT_BASE = 0.68;
              var LOCK_DURATION_BASE = 0.22;
              var CONFIRM_DURATION_BASE = 0.2;
              var PULSE_HALF_BASE = 0.18;

              var duration = Math.max(0.001, parseFloat(root.dataset.duration || "4"));
              var totalBase = IN_BASE + OUT_BASE;
              var scale = duration < totalBase ? duration / totalBase : 1;
              var IN = IN_BASE * scale;
              var OUT = OUT_BASE * scale;
              var STAGE_IN = STAGE_IN_BASE * scale;
              var SWEEP_LANDS = SWEEP_LANDS_BASE * scale;
              var SWEEP_DURATION = (SWEEP_DURATION_BASE / sweepSpeed) * scale;
              var SWEEP_START = Math.max(0, SWEEP_LANDS - SWEEP_DURATION);
              var LOCK_AT = LOCK_AT_BASE * scale;
              var LOCK_DURATION = LOCK_DURATION_BASE * scale;
              var CONFIRM_DURATION = CONFIRM_DURATION_BASE * scale;
              var PULSE_HALF = PULSE_HALF_BASE * scale;
              var HOLD = Math.max(0, duration - (IN + OUT));
              var HOLD_START = IN;
              var OUT_START = IN + HOLD;

              function fireSfx(id, t) {
                root.dispatchEvent(
                  new CustomEvent("hf:sfx", { detail: { id: id, t: t }, bubbles: true }),
                );
              }

              // Explicit both-endpoints state before timeline construction keeps
              // direct seek to t=0 correct without playing through prior frames.
              gsap.set(stage, { opacity: 0, scale: 0.94 });
              gsap.set(cornerLayer, { scale: 1 });
              gsap.set(sweep, { opacity: 1, yPercent: 0 });
              gsap.set(target, { opacity: 0, scale: 0.96 });
              gsap.set(ambient, { opacity: 0, scale: 1 });
              gsap.set(pulse, { opacity: 0, scale: 0.9 });
              gsap.set(check, { opacity: 0, scale: 0.94 });
              gsap.set(label, { opacity: 0, y: "1.2cqh", scale: 0.96 });

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

              // IN: settle, scan, then lock. The sweep uses --ease-standard's
              // GSAP equivalent and lands at a fixed offset inside IN.
              tl.to(stage, { opacity: 1, scale: 1, duration: STAGE_IN, ease: "power2.out" }, 0);
              tl.to(
                sweep,
                { yPercent: 100, duration: SWEEP_DURATION, ease: "power2.out" },
                SWEEP_START,
              );
              tl.set(sweep, { opacity: 0 }, SWEEP_LANDS);

              // recognition-lock is the single causal gate. Corner tightening is
              // the one moderate --ease-overshoot motion in this primitive.
              tl.to(
                cornerLayer,
                { scale: 0.6, duration: LOCK_DURATION, ease: "back.out(1.7)" },
                LOCK_AT,
              );
              tl.to(
                target,
                { opacity: 1, scale: 1, duration: CONFIRM_DURATION, ease: "power2.out" },
                LOCK_AT,
              );
              tl.to(
                check,
                { opacity: 1, scale: 1, duration: CONFIRM_DURATION, ease: "power2.out" },
                LOCK_AT,
              );
              tl.to(
                label,
                { opacity: 1, y: 0, scale: 1, duration: CONFIRM_DURATION, ease: "power2.out" },
                LOCK_AT,
              );
              tl.to(
                pulse,
                {
                  opacity: 0.9,
                  scale: 1.25,
                  duration: PULSE_HALF,
                  ease: "power2.out",
                  yoyo: true,
                  repeat: 1,
                },
                LOCK_AT,
              );
              // Side-effect invariant: this timeline callback is the only actor
              // that emits lock-chime, once at the recognition-lock sync point.
              tl.call(
                function () {
                  fireSfx("lock-chime", LOCK_AT);
                },
                [],
                LOCK_AT,
              );

              // HOLD: a separate layer breathes with a finite repeat count, so
              // the resolved gate stays alive without competing with lock tweens.
              if (HOLD > AMBIENT_HALF) {
                var ambientRepeat = Math.max(0, Math.floor(HOLD / AMBIENT_HALF) - 1);
                tl.to(
                  ambient,
                  {
                    opacity: 0.3,
                    scale: 1.015,
                    duration: AMBIENT_HALF,
                    ease: "sine.inOut",
                    yoyo: true,
                    repeat: ambientRepeat,
                  },
                  HOLD_START,
                );
              }

              // OUT: asymmetric release. HOLD alone absorbs duration changes.
              tl.to(stage, { opacity: 0, scale: 0.98, duration: OUT, ease: "power2.in" }, OUT_START);

              tl.seek(0);

              window.__timelines = window.__timelines || {};
              window.__timelines[compositionId] = tl;
            })();
          </script>
        </div>
      </template>
    </body>
  </html>
  ```
</Accordion>

Tagged `prop` `ui-props` `camera` `qr` `scan` `recognition` `interaction` `demonstrate`.

## Related topics

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