> ## 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.

# Light Sweep Pass

> A traveling key light re-shades a slotted scene: a soft diagonal gradient band crosses the frame once while every per-element highlight and shadow shifts in lockstep (all driven by one --light-x property), then the light settles into a resting key. Quiet, expensive-feeling; the scene itself never moves. Callers fill the named scene slot; a token hero-and-cards default renders when it is left empty.

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/light-sweep-pass.json" compositionId="light-sweep-pass" compositionSrc="compositions/components/light-sweep-pass.html" variables={[{"id":"angle","type":"number","role":"style","label":"Angle","description":"Band and highlight gradient angle in degrees.","default":115,"min":60,"max":160,"step":1,"unit":"deg"},{"id":"sweep_at","type":"number","role":"timing","label":"Sweep start","description":"Seconds after mount start when the band starts crossing.","default":0.9,"min":0,"max":8,"step":0.05,"unit":"s"},{"id":"strength","type":"enum","role":"style","label":"Strength","description":"Band opacity and highlight bloom multiplier.","default":"standard","options":[{"value":"subtle","label":"Subtle"},{"value":"standard","label":"Standard"}]},{"id":"accent","type":"enum","role":"style","label":"Accent","description":"Tint inside the band and the highlight blooms.","default":"green","options":[{"value":"green","label":"Green"},{"value":"blue","label":"Blue"},{"value":"violet","label":"Violet"}]},{"id":"exit","type":"enum","role":"timing","label":"Exit","description":"Outgoing transition. None holds the settled key.","default":"none","options":[{"value":"none","label":"None"},{"value":"fade","label":"Fade"},{"value":"up","label":"Up"}]}]}>
  ```html light-sweep-pass.html theme={null}
  <!doctype html>
  <!--
    light-sweep-pass: HyperFrames video primitive (overlays / light)

    Concept: a traveling key light re-shades a slotted scene. A soft diagonal
    gradient band crosses the frame once while every per-element highlight and
    shadow shifts in lockstep, then the light settles into a resting key from
    the upper third. Quiet, expensive-feeling; the scene itself never moves.

    Wave L, unit L3. Reference: motion-reference/ordinaryfolkco
    2001090228958752945 (the traveling light band re-shading the frame).

    ONE PROPERTY OWNS THE PASS: --light-x (a unitless 0-100-ish scalar on
    #root) is the only animated value. The band's translate, every element's
    highlight bloom, every shadow offset, and the ambient lift all read it
    through calc()/clamp()/max() in static CSS. The timeline tweens a plain
    JS number proxy and writes --light-x in onUpdate (never a var() string),
    so seeks in any order resolve the same computed styles.

    Slot (see README.md for a worked example):
      - [data-slot="scene"]: the full-bleed scene being lit. Replace the
        children of this element in your installed copy. Default: a token
        hero card and three feature cards. Elements opt into the light with
        the data-lit attribute plus an inline --lsp-x (their center along
        the sweep axis, percent of frame width).

    Variables (declared in data-composition-variables below):
      - angle (number, degrees, default 115, 60 to 160): band and highlight
        gradient angle. 115 reads as upper-left key light.
      - sweep_at (number, seconds, default 0.9): when the band starts
        crossing, relative to mount start.
      - strength (subtle | standard, default standard): band opacity and
        highlight bloom multiplier. subtle is the barely-there pass.
      - accent (green | blue | violet, default green): warm tint inside the
        band and the highlight blooms. green maps to --brand, blue to
        --accent, violet to --accent-2.
      - exit (none | fade | up, default none): outgoing transition. none
        holds the settled key (frame roots own transitions).

    Envelope (fixed IN/OUT, elastic HOLD only, never gsap.timeScale()):
      IN       = sweep_at + 1.60s crossing + 0.55s settle to the resting key
      HOLD     = elastic = max(0, D - (IN + OUT)); the settled key is still
      OUT      = 0.50s when exit is fade or up, 0 when exit is none
      If D < IN + OUT, IN and OUT scale down together so IN + OUT == D.

    Sync point: sweep-land when the light reaches its resting key (3.05s at
    defaults). Dispatches a bubbling hf:sfx CustomEvent with id
    "light-settle-soft" there. This primitive never plays audio.

    Mount contract: MOUNTABLE SUB-COMPOSITION. The runtime clones only
    <template> contents; #root fills the host box (inset:0, container-type:
    size), has no data-width/data-height, and registers one paused timeline
    under the literal "light-sweep-pass" key. Variables come from
    window.__hyperframes.getVariables().
  -->
  <html
    lang="en"
    data-composition-id="light-sweep-pass"
    data-composition-duration="4"
    data-composition-variables='[
      { "id": "angle", "type": "number", "role": "style", "label": "Angle", "description": "Band and highlight gradient angle in degrees.", "default": 115, "min": 60, "max": 160, "step": 1, "unit": "deg" },
      { "id": "sweep_at", "type": "number", "role": "timing", "label": "Sweep start", "description": "Seconds after mount start when the band starts crossing.", "default": 0.9, "min": 0, "max": 8, "step": 0.05, "unit": "s" },
      { "id": "strength", "type": "enum", "role": "style", "label": "Strength", "description": "Band opacity and highlight bloom multiplier.", "default": "standard", "options": [{ "value": "subtle", "label": "Subtle" }, { "value": "standard", "label": "Standard" }] },
      { "id": "accent", "type": "enum", "role": "style", "label": "Accent", "description": "Tint inside the band and the highlight blooms.", "default": "green", "options": [{ "value": "green", "label": "Green" }, { "value": "blue", "label": "Blue" }, { "value": "violet", "label": "Violet" }] },
      { "id": "exit", "type": "enum", "role": "timing", "label": "Exit", "description": "Outgoing transition. None holds the settled key.", "default": "none", "options": [{ "value": "none", "label": "None" }, { "value": "fade", "label": "Fade" }, { "value": "up", "label": "Up" }] }
    ]'
  >
    <head>
      <meta charset="UTF-8" />
      <title>Light Sweep Pass</title>
    </head>
    <body>
      <template>
        <div id="root" data-composition-id="light-sweep-pass" data-duration="4" data-fps="30">
          <style>
            *,
            *::before,
            *::after {
              box-sizing: border-box;
            }

            /* --light-x starts off-frame left; the timeline is its only
               writer. --lsp-angle and --lsp-strength are set once at mount. */
            #root {
              --light-x: -35;
              --lsp-angle: 115;
              --lsp-strength: 1;
              position: absolute;
              inset: 0;
              container-type: size;
              isolation: isolate;
              overflow: hidden;
              background: var(--bg, #0b0c0e);
              color: var(--fg, #f8fafc);
              font-family: var(--font-body, Inter, system-ui, sans-serif);
            }

            .lsp-clip,
            .lsp-stage,
            .lsp-scene,
            .lsp-ambient,
            .lsp-band {
              position: absolute;
              inset: 0;
            }

            .lsp-clip {
              overflow: hidden;
            }

            .lsp-stage {
              opacity: 0;
            }

            .lsp-scene {
              overflow: hidden;
            }

            /* Every lit element derives its whole treatment from the ONE
               --light-x scalar: distance d to the band, |d| via max(d, -d),
               a 0..1 proximity bloom, a shadow that slides away from the
               light and deepens as the band passes. Elements opt in with
               data-lit and an inline --lsp-x (center along the sweep axis,
               percent of frame width). */
            [data-lit] {
              --lsp-d: calc(var(--light-x) - var(--lsp-x, 50));
              --lsp-abs: max(var(--lsp-d), calc(-1 * var(--lsp-d)));
              --lsp-glow: clamp(0, calc(1 - var(--lsp-abs) / 26), 1);
              position: relative;
              box-shadow: calc(clamp(-30, var(--lsp-d), 30) * -0.05cqw)
                calc(0.8cqh + var(--lsp-glow) * 0.7cqh) calc(2.2cqh + var(--lsp-glow) * 2.4cqh)
                color-mix(in srgb, #000000 26%, transparent);
            }

            /* The highlight bloom: a static angle-matched gradient whose
               opacity is the proximity term. No transitions, no tweens. */
            [data-lit]::after {
              content: "";
              position: absolute;
              inset: 0;
              border-radius: inherit;
              pointer-events: none;
              background: linear-gradient(
                calc(var(--lsp-angle) * 1deg),
                color-mix(in srgb, #ffffff 86%, var(--lsp-accent, #22c55e)) 0%,
                transparent 62%
              );
              opacity: calc(var(--lsp-glow) * 0.32 * var(--lsp-strength));
            }

            /* Ambient lift: the scene starts a touch dim and brightens for
               good once the band has entered the frame. Monotonic in
               --light-x, so the settle never re-dims it. */
            .lsp-ambient {
              pointer-events: none;
              background: #000000;
              opacity: calc(clamp(0, (26 - var(--light-x)) / 130, 0.16) * var(--lsp-strength));
            }

            /* The band: an oversized angle-matched gradient sheet that only
               ever translates along X, driven by the same scalar. Screen
               blend keeps it a light, never a paint. */
            .lsp-band {
              inset: -55%;
              pointer-events: none;
              mix-blend-mode: screen;
              background: linear-gradient(
                calc(var(--lsp-angle) * 1deg),
                transparent 36%,
                color-mix(in srgb, #ffffff 24%, transparent) 46%,
                color-mix(in srgb, #ffffff 78%, var(--lsp-accent, #22c55e)) 50%,
                color-mix(in srgb, #ffffff 24%, transparent) 54%,
                transparent 64%
              );
              opacity: 0;
              transform: translateX(calc((var(--light-x) - 50) * 1.4cqw));
              will-change: transform, opacity;
            }

            #root[data-strength="subtle"] {
              --lsp-strength: 0.55;
            }

            /* ---------- default slot scene: token hero + three cards ---------- */

            .lsp-default {
              position: absolute;
              inset: 0;
              display: grid;
              grid-template-rows: auto auto;
              align-content: center;
              justify-items: center;
              row-gap: var(--space-3, 5cqh);
              padding: var(--space-3, 6cqh) 10cqw;
              background: linear-gradient(
                calc(var(--lsp-angle) * 1deg),
                color-mix(in srgb, var(--fg, #f8fafc) 3%, var(--bg, #0b0c0e)) 0%,
                var(--bg, #0b0c0e) 55%,
                color-mix(in srgb, #000000 6%, var(--bg, #0b0c0e)) 100%
              );
            }

            .lsp-hero {
              display: grid;
              align-content: center;
              row-gap: var(--space-2, 2.4cqh);
              width: 58cqw;
              height: 30cqh;
              padding: var(--space-3, 4cqh) var(--space-3, 3cqw);
              border: 0.16cqw solid var(--border, #343a46);
              border-radius: var(--radius, 2.4cqmin);
              background: var(--surface, #14171c);
            }

            .lsp-hero-bar {
              width: 46%;
              height: 4.6cqh;
              border-radius: 1.4cqh;
              background: color-mix(in srgb, var(--fg, #f8fafc) 82%, var(--surface, #14171c));
            }

            .lsp-hero-line {
              height: 2.2cqh;
              border-radius: 1.1cqh;
              background: var(--muted, #94a3b8);
              opacity: 0.55;
            }

            .lsp-hero-line:nth-of-type(3) {
              width: 72%;
            }

            .lsp-row {
              display: grid;
              grid-template-columns: repeat(3, 1fr);
              column-gap: var(--space-2, 2cqw);
              width: 58cqw;
            }

            .lsp-card {
              display: grid;
              align-content: start;
              row-gap: var(--space-1, 1.6cqh);
              height: 24cqh;
              padding: var(--space-2, 2.6cqh) var(--space-2, 1.6cqw);
              border: 0.16cqw solid var(--border, #343a46);
              border-radius: var(--radius, 2.4cqmin);
              background: var(--surface, #14171c);
            }

            .lsp-dot {
              width: 3.4cqh;
              height: 3.4cqh;
              border-radius: 50%;
              background: color-mix(in srgb, var(--lsp-accent, #22c55e) 72%, var(--surface, #14171c));
            }

            .lsp-line {
              height: 1.9cqh;
              border-radius: 1cqh;
              background: var(--muted, #94a3b8);
              opacity: 0.5;
            }

            .lsp-line:nth-of-type(3) {
              width: 64%;
            }
          </style>

          <div
            id="light-sweep-pass-clip"
            class="lsp-clip clip"
            data-start="0"
            data-duration="4"
            data-track-index="0"
          >
            <div class="lsp-stage">
              <div class="lsp-scene" data-slot="scene">
                <!-- SLOT "scene": replace the children of this element with
                     your own full-bleed content. Mark elements that should
                     catch the light with data-lit and give each an inline
                     style="--lsp-x: NN" (center along the sweep, percent). -->
                <div class="lsp-default" aria-hidden="true">
                  <div class="lsp-hero" data-lit style="--lsp-x: 50">
                    <div class="lsp-hero-bar"></div>
                    <div class="lsp-hero-line"></div>
                    <div class="lsp-hero-line"></div>
                  </div>
                  <div class="lsp-row">
                    <div class="lsp-card" data-lit style="--lsp-x: 31">
                      <div class="lsp-dot"></div>
                      <div class="lsp-line"></div>
                      <div class="lsp-line"></div>
                    </div>
                    <div class="lsp-card" data-lit style="--lsp-x: 50">
                      <div class="lsp-dot"></div>
                      <div class="lsp-line"></div>
                      <div class="lsp-line"></div>
                    </div>
                    <div class="lsp-card" data-lit style="--lsp-x: 69">
                      <div class="lsp-dot"></div>
                      <div class="lsp-line"></div>
                      <div class="lsp-line"></div>
                    </div>
                  </div>
                </div>
              </div>
              <div class="lsp-ambient" aria-hidden="true"></div>
              <div class="lsp-band" aria-hidden="true"></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 id: mount flattening strips data-composition-id from the
              // live root before this timeline registers.
              var compositionId = "light-sweep-pass";
              var stage = root.querySelector(".lsp-stage");
              var band = root.querySelector(".lsp-band");

              var vars =
                window.__hyperframes && window.__hyperframes.getVariables
                  ? window.__hyperframes.getVariables()
                  : {};

              function clampNumber(raw, fallback, min, max) {
                var value = raw == null ? fallback : Number(raw);
                if (!Number.isFinite(value)) return fallback;
                return Math.max(min, Math.min(max, value));
              }

              var angle = clampNumber(vars.angle, 115, 60, 160);
              var sweepAt = clampNumber(vars.sweep_at, 0.9, 0, 8);
              var strength = vars.strength === "subtle" ? "subtle" : "standard";
              var accentTokens = {
                green: "var(--brand, #22c55e)",
                blue: "var(--accent, #38bdf8)",
                violet: "var(--accent-2, #c5a3ff)",
              };
              var accent = Object.prototype.hasOwnProperty.call(accentTokens, vars.accent)
                ? vars.accent
                : "green";
              // The bundler mirrors composition variables as scoped CSS custom
              // props, so this unit's own accent variable can shadow the contract
              // --accent token ("blue" is a valid CSS color). When the shadow is
              // present, fall back to the literal contract value.
              var shadowedAccent = getComputedStyle(root).getPropertyValue("--accent").trim();
              if (
                shadowedAccent === "green" ||
                shadowedAccent === "blue" ||
                shadowedAccent === "violet"
              ) {
                accentTokens.blue = "#38bdf8";
              }
              // INVARIANT: only none | fade | up reaches the timeline.
              var exit = vars.exit === "fade" || vars.exit === "up" ? vars.exit : "none";

              root.dataset.strength = strength;
              root.style.setProperty("--lsp-angle", String(angle));
              root.style.setProperty("--lsp-accent", accentTokens[accent]);

              // RETIME RANGE: fixed IN and OUT scale together only when D is
              // too short. HOLD is the sole elastic phase. Never timeScale().
              var SWEEP_BASE = 1.6;
              var SETTLE_BASE = 0.55;
              var STAGE_IN_BASE = 0.5;
              var IN_BASE = sweepAt + SWEEP_BASE + SETTLE_BASE;
              var OUT_BASE = exit === "none" ? 0 : 0.5;

              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 SWEEP = SWEEP_BASE * scale;
              var SETTLE = SETTLE_BASE * scale;
              var STAGE_IN = Math.min(STAGE_IN_BASE * scale, IN_BASE * scale);
              var SWEEP_AT = sweepAt * scale;
              var SWEEP_END = SWEEP_AT + SWEEP;
              var IN = IN_BASE * scale;
              var OUT = OUT_BASE * scale;
              var HOLD = Math.max(0, duration - (IN + OUT));
              var OUT_START = IN + HOLD;

              // The light's authored waypoints: parked off-frame left, fully
              // crossed off-frame right, then the resting key in the upper
              // third of the travel. All in --light-x units (frame percent).
              var LIGHT_START = -35;
              var LIGHT_CROSSED = 118;
              var LIGHT_REST = 62;

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

              // ONE proxy owns --light-x; every highlight, shadow, ambient
              // lift, and the band transform read it via calc in static CSS.
              var light = { x: LIGHT_START };
              function writeLight() {
                root.style.setProperty("--light-x", light.x.toFixed(3));
              }
              writeLight();

              gsap.set(stage, { opacity: 0, y: "1.5cqh" });
              gsap.set(band, { autoAlpha: 0 });

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

              // IN: the scene settles first, then one confident crossing.
              tl.to(stage, { opacity: 1, y: "0cqh", duration: STAGE_IN, ease: "power2.out" }, 0);
              tl.fromTo(
                light,
                { x: LIGHT_START },
                {
                  x: LIGHT_CROSSED,
                  duration: SWEEP,
                  ease: "sine.inOut",
                  onUpdate: writeLight,
                },
                SWEEP_AT,
              );
              tl.fromTo(
                band,
                { autoAlpha: 0 },
                {
                  autoAlpha: 1,
                  duration: Math.min(0.3 * scale, SWEEP),
                  ease: "power1.out",
                  immediateRender: false,
                },
                SWEEP_AT,
              );
              tl.to(
                band,
                { autoAlpha: 0, duration: 0.35 * scale, ease: "power1.in" },
                Math.max(SWEEP_AT, SWEEP_END - 0.35 * scale),
              );

              // The settle: the band is gone; the key light glides back to its
              // resting position and the per-element shading follows it there.
              tl.to(
                light,
                { x: LIGHT_REST, duration: SETTLE, ease: "power2.out", onUpdate: writeLight },
                SWEEP_END,
              );
              tl.call(
                function () {
                  fireSfx("light-settle-soft", IN);
                },
                [],
                IN,
              );

              // HOLD: deliberately still under the settled key.

              // OUT: only when the exit variable asks for one.
              if (exit !== "none") {
                tl.to(stage, { opacity: 0, duration: OUT, ease: "power2.in" }, OUT_START);
                if (exit === "up") {
                  tl.to(stage, { y: "-6cqh", 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 light-sweep-pass" item="light-sweep-pass" />

That writes one file: `compositions/components/light-sweep-pass.html`.

## Paste it into your composition

Open `compositions/components/light-sweep-pass.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                                             |
| ---------- | ---------- | -------------------------- | -------------------------------------------------------- |
| `angle`    | `115`      | 60deg to 160deg, step 1deg | Band and highlight gradient angle in degrees.            |
| `sweep_at` | `0.9`      | 0s to 8s, step 0.05s       | Seconds after mount start when the band starts crossing. |
| `strength` | `standard` | `subtle`, `standard`       | Band opacity and highlight bloom multiplier.             |
| `accent`   | `green`    | `green`, `blue`, `violet`  | Tint inside the band and the highlight blooms.           |
| `exit`     | `none`     | `none`, `fade`, `up`       | Outgoing transition. None holds the settled key.         |

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="light-sweep-pass"
  data-composition-src="compositions/components/light-sweep-pass.html"
  data-variable-values='{"angle":115,"sweep_at":0.9,"strength":"standard","accent":"green","exit":"none"}'
></div>
```

## Source

<Accordion title={`light-sweep-pass.html`}>
  ```html theme={null}
  <!doctype html>
  <!--
    light-sweep-pass: HyperFrames video primitive (overlays / light)

    Concept: a traveling key light re-shades a slotted scene. A soft diagonal
    gradient band crosses the frame once while every per-element highlight and
    shadow shifts in lockstep, then the light settles into a resting key from
    the upper third. Quiet, expensive-feeling; the scene itself never moves.

    Wave L, unit L3. Reference: motion-reference/ordinaryfolkco
    2001090228958752945 (the traveling light band re-shading the frame).

    ONE PROPERTY OWNS THE PASS: --light-x (a unitless 0-100-ish scalar on
    #root) is the only animated value. The band's translate, every element's
    highlight bloom, every shadow offset, and the ambient lift all read it
    through calc()/clamp()/max() in static CSS. The timeline tweens a plain
    JS number proxy and writes --light-x in onUpdate (never a var() string),
    so seeks in any order resolve the same computed styles.

    Slot (see README.md for a worked example):
      - [data-slot="scene"]: the full-bleed scene being lit. Replace the
        children of this element in your installed copy. Default: a token
        hero card and three feature cards. Elements opt into the light with
        the data-lit attribute plus an inline --lsp-x (their center along
        the sweep axis, percent of frame width).

    Variables (declared in data-composition-variables below):
      - angle (number, degrees, default 115, 60 to 160): band and highlight
        gradient angle. 115 reads as upper-left key light.
      - sweep_at (number, seconds, default 0.9): when the band starts
        crossing, relative to mount start.
      - strength (subtle | standard, default standard): band opacity and
        highlight bloom multiplier. subtle is the barely-there pass.
      - accent (green | blue | violet, default green): warm tint inside the
        band and the highlight blooms. green maps to --brand, blue to
        --accent, violet to --accent-2.
      - exit (none | fade | up, default none): outgoing transition. none
        holds the settled key (frame roots own transitions).

    Envelope (fixed IN/OUT, elastic HOLD only, never gsap.timeScale()):
      IN       = sweep_at + 1.60s crossing + 0.55s settle to the resting key
      HOLD     = elastic = max(0, D - (IN + OUT)); the settled key is still
      OUT      = 0.50s when exit is fade or up, 0 when exit is none
      If D < IN + OUT, IN and OUT scale down together so IN + OUT == D.

    Sync point: sweep-land when the light reaches its resting key (3.05s at
    defaults). Dispatches a bubbling hf:sfx CustomEvent with id
    "light-settle-soft" there. This primitive never plays audio.

    Mount contract: MOUNTABLE SUB-COMPOSITION. The runtime clones only
    <template> contents; #root fills the host box (inset:0, container-type:
    size), has no data-width/data-height, and registers one paused timeline
    under the literal "light-sweep-pass" key. Variables come from
    window.__hyperframes.getVariables().
  -->
  <html
    lang="en"
    data-composition-id="light-sweep-pass"
    data-composition-duration="4"
    data-composition-variables='[
      { "id": "angle", "type": "number", "role": "style", "label": "Angle", "description": "Band and highlight gradient angle in degrees.", "default": 115, "min": 60, "max": 160, "step": 1, "unit": "deg" },
      { "id": "sweep_at", "type": "number", "role": "timing", "label": "Sweep start", "description": "Seconds after mount start when the band starts crossing.", "default": 0.9, "min": 0, "max": 8, "step": 0.05, "unit": "s" },
      { "id": "strength", "type": "enum", "role": "style", "label": "Strength", "description": "Band opacity and highlight bloom multiplier.", "default": "standard", "options": [{ "value": "subtle", "label": "Subtle" }, { "value": "standard", "label": "Standard" }] },
      { "id": "accent", "type": "enum", "role": "style", "label": "Accent", "description": "Tint inside the band and the highlight blooms.", "default": "green", "options": [{ "value": "green", "label": "Green" }, { "value": "blue", "label": "Blue" }, { "value": "violet", "label": "Violet" }] },
      { "id": "exit", "type": "enum", "role": "timing", "label": "Exit", "description": "Outgoing transition. None holds the settled key.", "default": "none", "options": [{ "value": "none", "label": "None" }, { "value": "fade", "label": "Fade" }, { "value": "up", "label": "Up" }] }
    ]'
  >
    <head>
      <meta charset="UTF-8" />
      <title>Light Sweep Pass</title>
    </head>
    <body>
      <template>
        <div id="root" data-composition-id="light-sweep-pass" data-duration="4" data-fps="30">
          <style>
            *,
            *::before,
            *::after {
              box-sizing: border-box;
            }

            /* --light-x starts off-frame left; the timeline is its only
               writer. --lsp-angle and --lsp-strength are set once at mount. */
            #root {
              --light-x: -35;
              --lsp-angle: 115;
              --lsp-strength: 1;
              position: absolute;
              inset: 0;
              container-type: size;
              isolation: isolate;
              overflow: hidden;
              background: var(--bg, #0b0c0e);
              color: var(--fg, #f8fafc);
              font-family: var(--font-body, Inter, system-ui, sans-serif);
            }

            .lsp-clip,
            .lsp-stage,
            .lsp-scene,
            .lsp-ambient,
            .lsp-band {
              position: absolute;
              inset: 0;
            }

            .lsp-clip {
              overflow: hidden;
            }

            .lsp-stage {
              opacity: 0;
            }

            .lsp-scene {
              overflow: hidden;
            }

            /* Every lit element derives its whole treatment from the ONE
               --light-x scalar: distance d to the band, |d| via max(d, -d),
               a 0..1 proximity bloom, a shadow that slides away from the
               light and deepens as the band passes. Elements opt in with
               data-lit and an inline --lsp-x (center along the sweep axis,
               percent of frame width). */
            [data-lit] {
              --lsp-d: calc(var(--light-x) - var(--lsp-x, 50));
              --lsp-abs: max(var(--lsp-d), calc(-1 * var(--lsp-d)));
              --lsp-glow: clamp(0, calc(1 - var(--lsp-abs) / 26), 1);
              position: relative;
              box-shadow: calc(clamp(-30, var(--lsp-d), 30) * -0.05cqw)
                calc(0.8cqh + var(--lsp-glow) * 0.7cqh) calc(2.2cqh + var(--lsp-glow) * 2.4cqh)
                color-mix(in srgb, #000000 26%, transparent);
            }

            /* The highlight bloom: a static angle-matched gradient whose
               opacity is the proximity term. No transitions, no tweens. */
            [data-lit]::after {
              content: "";
              position: absolute;
              inset: 0;
              border-radius: inherit;
              pointer-events: none;
              background: linear-gradient(
                calc(var(--lsp-angle) * 1deg),
                color-mix(in srgb, #ffffff 86%, var(--lsp-accent, #22c55e)) 0%,
                transparent 62%
              );
              opacity: calc(var(--lsp-glow) * 0.32 * var(--lsp-strength));
            }

            /* Ambient lift: the scene starts a touch dim and brightens for
               good once the band has entered the frame. Monotonic in
               --light-x, so the settle never re-dims it. */
            .lsp-ambient {
              pointer-events: none;
              background: #000000;
              opacity: calc(clamp(0, (26 - var(--light-x)) / 130, 0.16) * var(--lsp-strength));
            }

            /* The band: an oversized angle-matched gradient sheet that only
               ever translates along X, driven by the same scalar. Screen
               blend keeps it a light, never a paint. */
            .lsp-band {
              inset: -55%;
              pointer-events: none;
              mix-blend-mode: screen;
              background: linear-gradient(
                calc(var(--lsp-angle) * 1deg),
                transparent 36%,
                color-mix(in srgb, #ffffff 24%, transparent) 46%,
                color-mix(in srgb, #ffffff 78%, var(--lsp-accent, #22c55e)) 50%,
                color-mix(in srgb, #ffffff 24%, transparent) 54%,
                transparent 64%
              );
              opacity: 0;
              transform: translateX(calc((var(--light-x) - 50) * 1.4cqw));
              will-change: transform, opacity;
            }

            #root[data-strength="subtle"] {
              --lsp-strength: 0.55;
            }

            /* ---------- default slot scene: token hero + three cards ---------- */

            .lsp-default {
              position: absolute;
              inset: 0;
              display: grid;
              grid-template-rows: auto auto;
              align-content: center;
              justify-items: center;
              row-gap: var(--space-3, 5cqh);
              padding: var(--space-3, 6cqh) 10cqw;
              background: linear-gradient(
                calc(var(--lsp-angle) * 1deg),
                color-mix(in srgb, var(--fg, #f8fafc) 3%, var(--bg, #0b0c0e)) 0%,
                var(--bg, #0b0c0e) 55%,
                color-mix(in srgb, #000000 6%, var(--bg, #0b0c0e)) 100%
              );
            }

            .lsp-hero {
              display: grid;
              align-content: center;
              row-gap: var(--space-2, 2.4cqh);
              width: 58cqw;
              height: 30cqh;
              padding: var(--space-3, 4cqh) var(--space-3, 3cqw);
              border: 0.16cqw solid var(--border, #343a46);
              border-radius: var(--radius, 2.4cqmin);
              background: var(--surface, #14171c);
            }

            .lsp-hero-bar {
              width: 46%;
              height: 4.6cqh;
              border-radius: 1.4cqh;
              background: color-mix(in srgb, var(--fg, #f8fafc) 82%, var(--surface, #14171c));
            }

            .lsp-hero-line {
              height: 2.2cqh;
              border-radius: 1.1cqh;
              background: var(--muted, #94a3b8);
              opacity: 0.55;
            }

            .lsp-hero-line:nth-of-type(3) {
              width: 72%;
            }

            .lsp-row {
              display: grid;
              grid-template-columns: repeat(3, 1fr);
              column-gap: var(--space-2, 2cqw);
              width: 58cqw;
            }

            .lsp-card {
              display: grid;
              align-content: start;
              row-gap: var(--space-1, 1.6cqh);
              height: 24cqh;
              padding: var(--space-2, 2.6cqh) var(--space-2, 1.6cqw);
              border: 0.16cqw solid var(--border, #343a46);
              border-radius: var(--radius, 2.4cqmin);
              background: var(--surface, #14171c);
            }

            .lsp-dot {
              width: 3.4cqh;
              height: 3.4cqh;
              border-radius: 50%;
              background: color-mix(in srgb, var(--lsp-accent, #22c55e) 72%, var(--surface, #14171c));
            }

            .lsp-line {
              height: 1.9cqh;
              border-radius: 1cqh;
              background: var(--muted, #94a3b8);
              opacity: 0.5;
            }

            .lsp-line:nth-of-type(3) {
              width: 64%;
            }
          </style>

          <div
            id="light-sweep-pass-clip"
            class="lsp-clip clip"
            data-start="0"
            data-duration="4"
            data-track-index="0"
          >
            <div class="lsp-stage">
              <div class="lsp-scene" data-slot="scene">
                <!-- SLOT "scene": replace the children of this element with
                     your own full-bleed content. Mark elements that should
                     catch the light with data-lit and give each an inline
                     style="--lsp-x: NN" (center along the sweep, percent). -->
                <div class="lsp-default" aria-hidden="true">
                  <div class="lsp-hero" data-lit style="--lsp-x: 50">
                    <div class="lsp-hero-bar"></div>
                    <div class="lsp-hero-line"></div>
                    <div class="lsp-hero-line"></div>
                  </div>
                  <div class="lsp-row">
                    <div class="lsp-card" data-lit style="--lsp-x: 31">
                      <div class="lsp-dot"></div>
                      <div class="lsp-line"></div>
                      <div class="lsp-line"></div>
                    </div>
                    <div class="lsp-card" data-lit style="--lsp-x: 50">
                      <div class="lsp-dot"></div>
                      <div class="lsp-line"></div>
                      <div class="lsp-line"></div>
                    </div>
                    <div class="lsp-card" data-lit style="--lsp-x: 69">
                      <div class="lsp-dot"></div>
                      <div class="lsp-line"></div>
                      <div class="lsp-line"></div>
                    </div>
                  </div>
                </div>
              </div>
              <div class="lsp-ambient" aria-hidden="true"></div>
              <div class="lsp-band" aria-hidden="true"></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 id: mount flattening strips data-composition-id from the
              // live root before this timeline registers.
              var compositionId = "light-sweep-pass";
              var stage = root.querySelector(".lsp-stage");
              var band = root.querySelector(".lsp-band");

              var vars =
                window.__hyperframes && window.__hyperframes.getVariables
                  ? window.__hyperframes.getVariables()
                  : {};

              function clampNumber(raw, fallback, min, max) {
                var value = raw == null ? fallback : Number(raw);
                if (!Number.isFinite(value)) return fallback;
                return Math.max(min, Math.min(max, value));
              }

              var angle = clampNumber(vars.angle, 115, 60, 160);
              var sweepAt = clampNumber(vars.sweep_at, 0.9, 0, 8);
              var strength = vars.strength === "subtle" ? "subtle" : "standard";
              var accentTokens = {
                green: "var(--brand, #22c55e)",
                blue: "var(--accent, #38bdf8)",
                violet: "var(--accent-2, #c5a3ff)",
              };
              var accent = Object.prototype.hasOwnProperty.call(accentTokens, vars.accent)
                ? vars.accent
                : "green";
              // The bundler mirrors composition variables as scoped CSS custom
              // props, so this unit's own accent variable can shadow the contract
              // --accent token ("blue" is a valid CSS color). When the shadow is
              // present, fall back to the literal contract value.
              var shadowedAccent = getComputedStyle(root).getPropertyValue("--accent").trim();
              if (
                shadowedAccent === "green" ||
                shadowedAccent === "blue" ||
                shadowedAccent === "violet"
              ) {
                accentTokens.blue = "#38bdf8";
              }
              // INVARIANT: only none | fade | up reaches the timeline.
              var exit = vars.exit === "fade" || vars.exit === "up" ? vars.exit : "none";

              root.dataset.strength = strength;
              root.style.setProperty("--lsp-angle", String(angle));
              root.style.setProperty("--lsp-accent", accentTokens[accent]);

              // RETIME RANGE: fixed IN and OUT scale together only when D is
              // too short. HOLD is the sole elastic phase. Never timeScale().
              var SWEEP_BASE = 1.6;
              var SETTLE_BASE = 0.55;
              var STAGE_IN_BASE = 0.5;
              var IN_BASE = sweepAt + SWEEP_BASE + SETTLE_BASE;
              var OUT_BASE = exit === "none" ? 0 : 0.5;

              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 SWEEP = SWEEP_BASE * scale;
              var SETTLE = SETTLE_BASE * scale;
              var STAGE_IN = Math.min(STAGE_IN_BASE * scale, IN_BASE * scale);
              var SWEEP_AT = sweepAt * scale;
              var SWEEP_END = SWEEP_AT + SWEEP;
              var IN = IN_BASE * scale;
              var OUT = OUT_BASE * scale;
              var HOLD = Math.max(0, duration - (IN + OUT));
              var OUT_START = IN + HOLD;

              // The light's authored waypoints: parked off-frame left, fully
              // crossed off-frame right, then the resting key in the upper
              // third of the travel. All in --light-x units (frame percent).
              var LIGHT_START = -35;
              var LIGHT_CROSSED = 118;
              var LIGHT_REST = 62;

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

              // ONE proxy owns --light-x; every highlight, shadow, ambient
              // lift, and the band transform read it via calc in static CSS.
              var light = { x: LIGHT_START };
              function writeLight() {
                root.style.setProperty("--light-x", light.x.toFixed(3));
              }
              writeLight();

              gsap.set(stage, { opacity: 0, y: "1.5cqh" });
              gsap.set(band, { autoAlpha: 0 });

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

              // IN: the scene settles first, then one confident crossing.
              tl.to(stage, { opacity: 1, y: "0cqh", duration: STAGE_IN, ease: "power2.out" }, 0);
              tl.fromTo(
                light,
                { x: LIGHT_START },
                {
                  x: LIGHT_CROSSED,
                  duration: SWEEP,
                  ease: "sine.inOut",
                  onUpdate: writeLight,
                },
                SWEEP_AT,
              );
              tl.fromTo(
                band,
                { autoAlpha: 0 },
                {
                  autoAlpha: 1,
                  duration: Math.min(0.3 * scale, SWEEP),
                  ease: "power1.out",
                  immediateRender: false,
                },
                SWEEP_AT,
              );
              tl.to(
                band,
                { autoAlpha: 0, duration: 0.35 * scale, ease: "power1.in" },
                Math.max(SWEEP_AT, SWEEP_END - 0.35 * scale),
              );

              // The settle: the band is gone; the key light glides back to its
              // resting position and the per-element shading follows it there.
              tl.to(
                light,
                { x: LIGHT_REST, duration: SETTLE, ease: "power2.out", onUpdate: writeLight },
                SWEEP_END,
              );
              tl.call(
                function () {
                  fireSfx("light-settle-soft", IN);
                },
                [],
                IN,
              );

              // HOLD: deliberately still under the settled key.

              // OUT: only when the exit variable asks for one.
              if (exit !== "none") {
                tl.to(stage, { opacity: 0, duration: OUT, ease: "power2.in" }, OUT_START);
                if (exit === "up") {
                  tl.to(stage, { y: "-6cqh", 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 `motion-primitive` `overlay` `light` `sweep` `slots` `deterministic`.

## Related topics

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