Staggered Fade Up

<!--
  Staggered Fade Up - 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 driving one offset, one scale and one blur, and these decide
  what that offset means on screen and what colour the words arrive in.

    - direction (up | down | left | right, default up): where the offset the
      timeline drives points. up rises into place, down drops in, left and
      right slide in along the baseline.
    - distance (close | standard | far, default standard): scales that offset,
      so the words cover a shorter or longer run in the same time. close covers
      half the run, far nearly double.
    - tone (ink | paper | accent, default ink): word colour. ink is near-black
      for light frames, paper near-white for dark ones, accent rides --brand.
      It writes its own property and never touches the shared --fg token.
    - words (text, default "Staggered fade up"): the words themselves, split on
      spaces, one span and one stagger step each. Anything empty, blank or not
      a string leaves the authored markup alone.

  On every default the result is identical to the original: three near-black
  words rise 22px through a 5px blur, 0.055s apart.
-->

<div
  class="hf-remocn-staggered-fade-up"
  data-composition-variables='[
    { "id": "direction", "type": "enum", "role": "motion", "label": "Direction", "description": "Where the offset the timeline drives points.", "default": "up", "options": [{ "value": "up", "label": "Up" }, { "value": "down", "label": "Down" }, { "value": "left", "label": "Left" }, { "value": "right", "label": "Right" }] },
    { "id": "distance", "type": "enum", "role": "motion", "label": "Distance", "description": "Scales the travel offset, so the words cover a shorter or longer run in the same time.", "default": "standard", "options": [{ "value": "close", "label": "Close" }, { "value": "standard", "label": "Standard" }, { "value": "far", "label": "Far" }] },
    { "id": "tone", "type": "enum", "role": "style", "label": "Tone", "description": "Word colour: ink for light frames, paper for dark ones, accent rides --brand.", "default": "ink", "options": [{ "value": "ink", "label": "Ink" }, { "value": "paper", "label": "Paper" }, { "value": "accent", "label": "Accent" }] },
    { "id": "words", "type": "string", "role": "content", "label": "Words", "description": "The words themselves, split on spaces, one span and one stagger step each.", "default": "Staggered fade up" }
  ]'
>
  <span>Staggered</span><span>fade</span><span>up</span>
</div>

<style>
  .hf-remocn-staggered-fade-up {
    color: var(--hf-fade-word-color, var(--fg, #18181b));
    font-family: var(--font-display, Inter, system-ui, sans-serif);
    font-weight: 900;
    letter-spacing: -0.04em;
  }
  .hf-remocn-staggered-fade-up {
    display: inline-flex;
    gap: var(--space-1, 12px);
    font-size: 56px;
    line-height: 1;
  }
  .hf-remocn-staggered-fade-up span {
    display: inline-block;
    transform: translate(
        calc(var(--hf-word-x, 0px) + var(--hf-word-y, 0px) * var(--hf-word-axis-x, 0)),
        calc(var(--hf-word-y, 0px) * var(--hf-word-axis-y, 1))
      )
      scale(var(--hf-word-scale, 1));
    filter: blur(var(--hf-word-blur, 0px));
    will-change: transform, filter, opacity;
  }
</style>

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

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

    // Unrecognised overrides return to their declared defaults.
    var axes = {
      up: { x: 0, y: 1 },
      down: { x: 0, y: -1 },
      left: { x: -1, y: 0 },
      right: { x: 1, y: 0 },
    };
    var reaches = { close: 0.5, standard: 1, far: 1.85 };
    var tones = {
      ink: "var(--fg, #18181b)",
      paper: "#fafafa",
      accent: "var(--brand, #34d399)",
    };

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

    var axis = axes[pick(axes, vars.direction, "up")];
    var reach = reaches[pick(reaches, vars.distance, "standard")];
    var tone = tones[pick(tones, vars.tone, "ink")];
    var words =
      typeof vars.words === "string" && vars.words.trim() ? vars.words.trim().split(/\s+/) : null;

    var roots = document.querySelectorAll(".hf-remocn-staggered-fade-up");
    for (var i = 0; i < roots.length; i += 1) {
      roots[i].style.setProperty("--hf-word-axis-x", String(axis.x * reach));
      roots[i].style.setProperty("--hf-word-axis-y", String(axis.y * reach));
      roots[i].style.setProperty("--hf-fade-word-color", tone);
      if (words) {
        roots[i].textContent = "";
        for (var j = 0; j < words.length; j += 1) {
          var span = document.createElement("span");
          span.textContent = words[j];
          roots[i].appendChild(span);
        }
      }
    }
  })();
</script>

<!--
  Timeline integration:
  tl.fromTo('.hf-remocn-staggered-fade-up span', { opacity: 0, '--hf-word-y': '22px', '--hf-word-scale': 0.92, '--hf-word-blur': '5px' }, { opacity: 1, '--hf-word-y': '0px', '--hf-word-scale': 1, '--hf-word-blur': '0px', duration: 0.3, stagger: 0.055, ease: 'power3.out' }, startTime);
-->