Strikethrough Replace

<!--
  Strikethrough Replace - remocn typography primitive for HyperFrames.

  Paste the markup, CSS and script into a composition. Drive the timeline
  integration from a paused GSAP timeline so renders remain deterministic.

  Variables. The script reads each one, falls back to the declared default on
  anything missing or unrecognised, and writes the result as a custom property
  the CSS below consumes. The timeline recipe at the bottom is untouched by
  them: it keeps drawing one strike and fading in one replacement, and these
  decide which way that strike draws and what the pair looks like.

    - origin (left | center | right, default left): the edge the strike grows
      out of while the timeline runs its scale from 0 to 1. left wipes forward,
      right wipes backward, center opens from the middle outwards. Once the
      line is fully drawn all three look the same, so this reads while the
      strike is drawing, not after it has landed.
    - thickness (thin | standard | thick, default standard): height of the
      strike line, 3px, 6px or 10px.
    - tint (red | amber | blue | violet, default red): strike colour. red and
      amber are literal, blue and violet ride --accent and --accent-2.
    - tone (ink | paper, default ink): colour of both words. ink is near-black
      for light frames, paper near-white for dark ones.

  On every default the result is identical to the original: a 6px red line
  wipes left to right across near-black text, then the replacement fades up.
-->

<div
  class="hf-remocn-strikethrough-replace"
  data-composition-variables='[
    { "id": "origin", "type": "enum", "role": "motion", "label": "Origin", "description": "Edge the strike grows out of as the timeline runs its scale from 0 to 1.", "default": "left", "options": [{ "value": "left", "label": "Left" }, { "value": "center", "label": "Center" }, { "value": "right", "label": "Right" }] },
    { "id": "thickness", "type": "enum", "role": "style", "label": "Thickness", "description": "Height of the strike line, from a hairline rule to a heavy bar.", "default": "standard", "options": [{ "value": "thin", "label": "Thin" }, { "value": "standard", "label": "Standard" }, { "value": "thick", "label": "Thick" }] },
    { "id": "tint", "type": "enum", "role": "style", "label": "Tint", "description": "Strike colour. Blue and violet ride --accent and --accent-2.", "default": "red", "options": [{ "value": "red", "label": "Red" }, { "value": "amber", "label": "Amber" }, { "value": "blue", "label": "Blue" }, { "value": "violet", "label": "Violet" }] },
    { "id": "tone", "type": "enum", "role": "style", "label": "Tone", "description": "Colour of both words: ink for light frames, paper for dark ones.", "default": "ink", "options": [{ "value": "ink", "label": "Ink" }, { "value": "paper", "label": "Paper" }] }
  ]'
>
  <span>Slow</span><i></i><strong>Fast</strong>
</div>

<style>
  .hf-remocn-strikethrough-replace {
    color: var(--hf-strike-text-color, #18181b);
    font-family: Inter, system-ui, sans-serif;
    font-weight: 900;
    letter-spacing: -0.04em;
  }
  .hf-remocn-strikethrough-replace {
    position: relative;
    display: inline-grid;
    grid-auto-flow: column;
    gap: 18px;
    align-items: center;
    font-size: 58px;
  }
  .hf-remocn-strikethrough-replace i {
    position: absolute;
    left: 0;
    width: 48%;
    height: var(--hf-strike-thickness, 6px);
    border-radius: 999px;
    background: var(--hf-strike-color, #ef4444);
    transform: scaleX(var(--hf-strike-progress, 1));
    transform-origin: var(--hf-strike-origin, left center);
  }
  .hf-remocn-strikethrough-replace strong {
    opacity: var(--hf-replace-opacity, 1);
  }
</style>

<script>
  (function () {
    "use strict";

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

    // Unrecognised overrides return to their declared defaults.
    var origins = { left: "left center", center: "center", right: "right center" };
    var thicknesses = { thin: "3px", standard: "6px", thick: "10px" };
    var tints = {
      red: "#ef4444",
      amber: "#f59e0b",
      blue: "var(--accent, #38bdf8)",
      violet: "var(--accent-2, #a78bfa)",
    };
    var tones = { ink: "#18181b", paper: "#fafafa" };

    function pick(table, value, fallback) {
      return Object.prototype.hasOwnProperty.call(table, value) ? value : fallback;
    }

    var origin = origins[pick(origins, vars.origin, "left")];
    var thickness = thicknesses[pick(thicknesses, vars.thickness, "standard")];
    var tint = tints[pick(tints, vars.tint, "red")];
    var tone = tones[pick(tones, vars.tone, "ink")];

    var roots = document.querySelectorAll(".hf-remocn-strikethrough-replace");
    for (var i = 0; i < roots.length; i += 1) {
      roots[i].style.setProperty("--hf-strike-origin", origin);
      roots[i].style.setProperty("--hf-strike-thickness", thickness);
      roots[i].style.setProperty("--hf-strike-color", tint);
      roots[i].style.setProperty("--hf-strike-text-color", tone);
    }
  })();
</script>

<!--
  Timeline integration:
  tl.fromTo('.hf-remocn-strikethrough-replace i', { '--hf-strike-progress': 0 }, { '--hf-strike-progress': 1, duration: 0.28, ease: 'power2.out' }, startTime); tl.fromTo('.hf-remocn-strikethrough-replace strong', { '--hf-replace-opacity': 0, y: 14 }, { '--hf-replace-opacity': 1, y: 0, duration: 0.3, ease: 'power2.out' }, startTime + 0.24);
-->