03Completed Step Whose Number Morphs Into a Drawn Checkmark

<main class="stage">
<div class="cm is-demo" id="cm">
  <ol class="cm__row" id="cmRow" role="list" aria-label="Application submission steps">
    <li class="cm__node" data-i="0">
      <span class="cm__circle" id="n0">
        <span class="cm__digit" id="d0">1</span>
        <svg class="cm__check" id="v0" viewBox="0 0 24 24" aria-hidden="true" focusable="false">
          <path class="cm__checkPath" id="p0" d="M5 12.5 L10 17.5 L19 6.5" />
        </svg>
      </span>
      <span class="cm__label">ID Check</span>
    </li>
    <li class="cm__connector"></li>
    <li class="cm__node" data-i="1">
      <span class="cm__circle" id="n1">
        <span class="cm__digit" id="d1">2</span>
        <svg class="cm__check" id="v1" viewBox="0 0 24 24" aria-hidden="true" focusable="false">
          <path class="cm__checkPath" id="p1" d="M5 12.5 L10 17.5 L19 6.5" />
        </svg>
      </span>
      <span class="cm__label">Documents</span>
    </li>
    <li class="cm__connector"></li>
    <li class="cm__node" data-i="2">
      <span class="cm__circle" id="n2">
        <span class="cm__digit" id="d2">3</span>
        <svg class="cm__check" id="v2" viewBox="0 0 24 24" aria-hidden="true" focusable="false">
          <path class="cm__checkPath" id="p2" d="M5 12.5 L10 17.5 L19 6.5" />
        </svg>
      </span>
      <span class="cm__label">Submitted</span>
    </li>
  </ol>
  <p class="cm__status" id="cmStatus" aria-live="polite">ID Check in progress</p>
  <div class="cm__controls">
    <button type="button" class="cm__btn" id="cmPrev">Back</button>
    <button type="button" class="cm__btn cm__btn--primary" id="cmNext">Done</button>
  </div>
</div>
</main>

@use "../../../../site/static/demo-tokens" as *;

// 핵심: 체크 표시는 SVG path 의 getTotalLength() 로 잰 실제 길이를 기준으로
// stroke-dashoffset = 길이 × (1 - progress) 를 매 프레임 계산해 그린다 — progress 는
// easeOutCubic(t) 로 구한 값이라 CSS 트랜지션이 아니라 JS 계산이 그림을 그린다.

$duration: $dur-base;
$easing: $ease-out;
$color: $stage-paper;

@include stage($stage-orange);

.cm {
  --cmGlow: 0;
  display: grid;
  gap: $sp-4;
  justify-items: center;
  width: min(92vw, 380px);
  background-image: radial-gradient(circle at 50% 30%, rgba(76, 212, 166, calc(var(--cmGlow, 0) * .2)), transparent 70%);
  border-radius: $r-card;
}

.cm__row {
  display: flex;
  align-items: flex-start;
  list-style: none;
  padding: 0;
  margin: 0;
  width: 100%;
}

.cm__node {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: $sp-1;
  flex: 0 0 auto;
}

.cm__circle {
  --drawGlow: 0;
  position: relative;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: rgba(255, 255, 255, .2);
  border: 2px solid rgba(255, 255, 255, .4);
  box-shadow: 0 0 calc(var(--drawGlow, 0) * 18px) rgba(76, 212, 166, calc(var(--drawGlow, 0) * .85));
  background-image: radial-gradient(circle at 50% 50%, rgba(76, 212, 166, calc(var(--drawGlow, 0) * .35)), transparent 70%);
}

.cm__circle.is-active {
  background: $stage-paper;
  border-color: $stage-paper;
}

.cm__circle.is-active .cm__digit { color: $subject-orange-deep; }

.cm__circle.is-done {
  background: $subject-ink;
  border-color: $subject-ink;
}

.cm__digit {
  position: absolute;
  font-size: 15px;
  font-weight: 700;
  color: $stage-paper;
}

.cm__check {
  position: absolute;
  width: 26px;
  height: 26px;
}

.cm__checkPath {
  fill: none;
  stroke: $subject-mint;
  stroke-width: 2.8;
  stroke-linecap: round;
  stroke-linejoin: round;
  opacity: 0;
}

.cm__label {
  font-size: 10px;
  color: rgba(255, 255, 255, .78);
  font-weight: 600;
}

.cm__connector {
  flex: 1 1 auto;
  height: 6px;
  min-width: 20px;
  margin: 20px 4px 0;
  border-radius: $r-pill;
  background: rgba(255, 255, 255, .24);
}

.cm__status {
  margin: 0;
  font-size: 11px;
  color: $stage-paper;
  font-weight: 700;
}

.cm__controls { display: flex; gap: $sp-2; }

.cm__btn {
  border: 1px solid rgba(255, 255, 255, .4);
  background: transparent;
  color: $stage-paper;
  border-radius: $r-control;
  padding: $sp-2 $sp-4;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
}

.cm__btn--primary {
  background: $subject-ink;
  border-color: $subject-ink;
}

.cm__btn:disabled { opacity: .4; cursor: default; }

.cm__btn:focus-visible {
  outline: 2px solid $stage-paper;
  outline-offset: 2px;
}

@media (max-width: 340px) {
  .cm__circle { width: 34px; height: 34px; }
  .cm__check { width: 22px; height: 22px; }
  .cm__label { font-size: 9px; }
  .cm__connector { height: 4px; margin: 16px 4px 0; }
}

@media (prefers-reduced-motion: reduce) {
  .cm__checkPath { transition: none; }
}

html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ff4d1f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.cm {
  --cmGlow: 0;
  display: grid;
  gap: 16px;
  justify-items: center;
  width: min(92vw, 380px);
  background-image: radial-gradient(circle at 50% 30%, rgba(76, 212, 166, calc(var(--cmGlow, 0) * 0.2)), transparent 70%);
  border-radius: 16px;
}

.cm__row {
  display: flex;
  align-items: flex-start;
  list-style: none;
  padding: 0;
  margin: 0;
  width: 100%;
}

.cm__node {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  flex: 0 0 auto;
}

.cm__circle {
  --drawGlow: 0;
  position: relative;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: rgba(255, 255, 255, 0.2);
  border: 2px solid rgba(255, 255, 255, 0.4);
  box-shadow: 0 0 calc(var(--drawGlow, 0) * 18px) rgba(76, 212, 166, calc(var(--drawGlow, 0) * 0.85));
  background-image: radial-gradient(circle at 50% 50%, rgba(76, 212, 166, calc(var(--drawGlow, 0) * 0.35)), transparent 70%);
}

.cm__circle.is-active {
  background: #ffffff;
  border-color: #ffffff;
}

.cm__circle.is-active .cm__digit {
  color: #c93000;
}

.cm__circle.is-done {
  background: #17141a;
  border-color: #17141a;
}

.cm__digit {
  position: absolute;
  font-size: 15px;
  font-weight: 700;
  color: #ffffff;
}

.cm__check {
  position: absolute;
  width: 26px;
  height: 26px;
}

.cm__checkPath {
  fill: none;
  stroke: #4cd4a6;
  stroke-width: 2.8;
  stroke-linecap: round;
  stroke-linejoin: round;
  opacity: 0;
}

.cm__label {
  font-size: 10px;
  color: rgba(255, 255, 255, 0.78);
  font-weight: 600;
}

.cm__connector {
  flex: 1 1 auto;
  height: 6px;
  min-width: 20px;
  margin: 20px 4px 0;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.24);
}

.cm__status {
  margin: 0;
  font-size: 11px;
  color: #ffffff;
  font-weight: 700;
}

.cm__controls {
  display: flex;
  gap: 8px;
}

.cm__btn {
  border: 1px solid rgba(255, 255, 255, 0.4);
  background: transparent;
  color: #ffffff;
  border-radius: 12px;
  padding: 8px 16px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
}

.cm__btn--primary {
  background: #17141a;
  border-color: #17141a;
}

.cm__btn:disabled {
  opacity: 0.4;
  cursor: default;
}

.cm__btn:focus-visible {
  outline: 2px solid #ffffff;
  outline-offset: 2px;
}

@media (max-width: 340px) {
  .cm__circle {
    width: 34px;
    height: 34px;
  }
  .cm__check {
    width: 22px;
    height: 22px;
  }
  .cm__label {
    font-size: 9px;
  }
  .cm__connector {
    height: 4px;
    margin: 16px 4px 0;
  }
}
@media (prefers-reduced-motion: reduce) {
  .cm__checkPath {
    transition: none;
  }
}

(function () {
  var STEP_CHECK_DRAW_MS = 640;
  var STEP_COUNT = 3;
  var LABELS = ['ID Check', 'Documents', 'Submitted'];
  var STATUS_TEXTS = ['ID Check in progress', 'Documents in progress', 'Submitted in progress'];

  var root = document.getElementById('cm');
  var status = document.getElementById('cmStatus');
  var prevBtn = document.getElementById('cmPrev');
  var nextBtn = document.getElementById('cmNext');
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

  var paths = [0, 1, 2].map(function (i) { return document.getElementById('p' + i); });
  var lengths = paths.map(function (p) { return p.getTotalLength(); });
  paths.forEach(function (p, i) { p.style.strokeDasharray = String(lengths[i]); p.style.strokeDashoffset = String(lengths[i]); });
  var digits = [0, 1, 2].map(function (i) { return document.getElementById('d' + i); });
  var circles = [0, 1, 2].map(function (i) { return document.getElementById('n' + i); });

  var current = 0;
  var done = [false, false, false];
  var anims = [null, null, null];

  function clamp(v, lo, hi) { return Math.max(lo, Math.min(hi, v)); }
  function easeOutCubic(t) { return 1 - Math.pow(1 - t, 3); }

  var progressState = [0, 0, 0];
  function setDrawProgress(i, progress) {
    var len = lengths[i];
    paths[i].style.strokeDashoffset = String(len * (1 - progress));
    digits[i].style.opacity = String(1 - progress);
    paths[i].style.opacity = String(progress);
    // 드로우 진행률을 노드 채움 색·링 글로우·카드 배경 톤에 같은 값으로 전파
    circles[i].style.setProperty('--drawGlow', progress.toFixed(3));
    progressState[i] = progress;
    root.style.setProperty('--cmGlow', Math.max(progressState[0], progressState[1], progressState[2]).toFixed(3));
  }

  function animateDraw(i, forward) {
    var startFrom = forward ? 0 : 1;
    var startTo = forward ? 1 : 0;
    if (reduce) { setDrawProgress(i, startTo); return; }
    var start = null;
    function step(now) {
      if (start === null) start = now;
      var t = clamp((now - start) / STEP_CHECK_DRAW_MS, 0, 1);
      var eased = easeOutCubic(t);
      var progress = startFrom + (startTo - startFrom) * eased;
      setDrawProgress(i, progress);
      if (t < 1) { anims[i] = requestAnimationFrame(step); } else { anims[i] = null; }
    }
    if (anims[i]) cancelAnimationFrame(anims[i]);
    anims[i] = requestAnimationFrame(step);
  }

  function render() {
    circles.forEach(function (el, i) {
      el.classList.toggle('is-active', i === current && !done[i]);
      el.classList.toggle('is-done', done[i]);
    });
    status.textContent = done[current] || current >= STEP_COUNT - 1 && done[STEP_COUNT - 1]
      ? 'All steps complete'
      : STATUS_TEXTS[current];
    prevBtn.disabled = current === 0;
    nextBtn.disabled = done[STEP_COUNT - 1];
  }

  function complete() {
    if (done[current]) return;
    done[current] = true;
    animateDraw(current, true);
    if (current < STEP_COUNT - 1) current += 1;
    render();
  }

  function back() {
    var target = done[current] ? current : current - 1;
    target = clamp(target, 0, STEP_COUNT - 1);
    if (done[target]) { done[target] = false; animateDraw(target, false); }
    current = target;
    render();
  }

  nextBtn.addEventListener('click', function () { root.classList.remove('is-demo'); complete(); });
  prevBtn.addEventListener('click', function () { root.classList.remove('is-demo'); back(); });
  root.addEventListener('keydown', function (e) {
    if (e.key === 'ArrowRight') { root.classList.remove('is-demo'); complete(); e.preventDefault(); }
    else if (e.key === 'ArrowLeft') { root.classList.remove('is-demo'); back(); e.preventDefault(); }
  });

  var startTime = null;
  var phase = 0;
  function loopTick(now) {
    if (startTime === null) startTime = now;
    var t = (now - startTime) / 1000 % 2;
    if (root.classList.contains('is-demo')) {
      if (t < 0.05 && phase !== 0) phase = 0;
      if (phase === 0 && t > 0.2) { complete(); phase = 1; }
      if (phase === 1 && t > 0.85) { complete(); phase = 2; }
      if (phase === 2 && t > 1.5) { complete(); phase = 3; }
      if (phase === 3 && t > 1.9) {
        [0, 1, 2].forEach(function (i) { if (anims[i]) { cancelAnimationFrame(anims[i]); anims[i] = null; } });
        done = [false, false, false]; current = 0;
        [0, 1, 2].forEach(function (i) { setDrawProgress(i, 0); });
        render(); phase = 4;
      }
    }
    requestAnimationFrame(loopTick);
  }

  render();
  requestAnimationFrame(loopTick);
})();

// StepCheckMorphDraw — vanilla 판(03-step-precision-check-morph-draw) 의 React 포트.
// 값 하나: 체크 path 의 getTotalLength() 로 잰 실제 길이 × (1 - easeOutCubic(t)) 를 매 프레임
// stroke-dashoffset 에 써서 "그려지는" 궤적을 만든다 — 숫자 opacity 는 그 반대값으로 동시에 뺀다.
import { useEffect, useRef, useState } from "react";
import styles from "./StepCheckMorphDraw.module.scss";

type Box<T> = { current: T };

const STEP_CHECK_DRAW_MS = 640;
const STEP_COUNT = 3;
const LABELS = ["본인확인", "서류작성", "제출완료"];
const STATUS_TEXTS = ["본인확인 진행 중", "서류작성 진행 중", "제출완료 진행 중"];
const STATUS_ALL_DONE = "모든 단계 완료";

function clamp(v: number, lo: number, hi: number): number {
  return Math.max(lo, Math.min(hi, v));
}
function easeOutCubic(t: number): number {
  return 1 - Math.pow(1 - t, 3);
}

export default function StepCheckMorphDraw() {
  const [current, setCurrent] = useState(0);
  const [done, setDone] = useState([false, false, false]);
  const [reduce, setReduce] = useState(false);
  const currentRef = useRef<number>(0) as Box<number>;
  const doneRef = useRef<boolean[]>([false, false, false]) as Box<boolean[]>;
  const demoRef = useRef<boolean>(true) as Box<boolean>;
  const pathRefs = useRef<Array<SVGPathElement | null>>([null, null, null]) as Box<Array<SVGPathElement | null>>;
  const digitRefs = useRef<Array<HTMLSpanElement | null>>([null, null, null]) as Box<Array<HTMLSpanElement | null>>;
  const circleRefs = useRef<Array<HTMLSpanElement | null>>([null, null, null]) as Box<Array<HTMLSpanElement | null>>;
  const lengthsRef = useRef<number[]>([0, 0, 0]) as Box<number[]>;
  const progressStateRef = useRef<number[]>([0, 0, 0]) as Box<number[]>;
  const rootRef = useRef<HTMLDivElement | null>(null) as Box<HTMLDivElement | null>;
  const animsRef = useRef<Array<number | null>>([null, null, null]) as Box<Array<number | null>>;
  const frameRef = useRef<number>(0) as Box<number>;

  useEffect(() => {
    setReduce(window.matchMedia("(prefers-reduced-motion: reduce)").matches);
    lengthsRef.current = pathRefs.current.map((p) => (p ? p.getTotalLength() : 0));
    pathRefs.current.forEach((p, i) => {
      if (!p) return;
      p.style.strokeDasharray = String(lengthsRef.current[i]);
      p.style.strokeDashoffset = String(lengthsRef.current[i]);
    });
  }, []);

  function setDrawProgress(i: number, progress: number): void {
    const len = lengthsRef.current[i];
    const p = pathRefs.current[i];
    const d = digitRefs.current[i];
    const c = circleRefs.current[i];
    if (p) { p.style.strokeDashoffset = String(len * (1 - progress)); p.style.opacity = String(progress); }
    if (d) d.style.opacity = String(1 - progress);
    if (c) c.style.setProperty("--drawGlow", progress.toFixed(3));
    progressStateRef.current[i] = progress;
    if (rootRef.current) {
      const g = Math.max(progressStateRef.current[0], progressStateRef.current[1], progressStateRef.current[2]);
      rootRef.current.style.setProperty("--cmGlow", g.toFixed(3));
    }
  }

  function animateDraw(i: number, forward: boolean): void {
    const startFrom = forward ? 0 : 1;
    const startTo = forward ? 1 : 0;
    if (reduce) { setDrawProgress(i, startTo); return; }
    let start = 0;
    function step(now: number): void {
      if (start === 0) start = now;
      const t = clamp((now - start) / STEP_CHECK_DRAW_MS, 0, 1);
      const eased = easeOutCubic(t);
      setDrawProgress(i, startFrom + (startTo - startFrom) * eased);
      animsRef.current[i] = t < 1 ? requestAnimationFrame(step) : null;
    }
    const existing = animsRef.current[i];
    if (existing) cancelAnimationFrame(existing);
    animsRef.current[i] = requestAnimationFrame(step);
  }

  function complete(): void {
    const cur = currentRef.current;
    if (doneRef.current[cur]) return;
    const nextDone = doneRef.current.slice();
    nextDone[cur] = true;
    doneRef.current = nextDone;
    setDone(nextDone);
    animateDraw(cur, true);
    if (cur < STEP_COUNT - 1) { currentRef.current = cur + 1; setCurrent(cur + 1); }
  }

  function back(): void {
    const cur = currentRef.current;
    const target = clamp(doneRef.current[cur] ? cur : cur - 1, 0, STEP_COUNT - 1);
    if (doneRef.current[target]) {
      const nextDone = doneRef.current.slice();
      nextDone[target] = false;
      doneRef.current = nextDone;
      setDone(nextDone);
      animateDraw(target, false);
    }
    currentRef.current = target;
    setCurrent(target);
  }

  function stopDemo(): void { demoRef.current = false; }

  useEffect(() => {
    let startTime = 0;
    let phase = 0;
    function loopTick(now: number): void {
      if (startTime === 0) startTime = now;
      const t = ((now - startTime) / 1000) % 2;
      if (demoRef.current) {
        if (t < 0.05 && phase !== 0) phase = 0;
        if (phase === 0 && t > 0.2) { complete(); phase = 1; }
        if (phase === 1 && t > 0.85) { complete(); phase = 2; }
        if (phase === 2 && t > 1.5) { complete(); phase = 3; }
        if (phase === 3 && t > 1.9) {
          [0, 1, 2].forEach((i) => {
            const existing = animsRef.current[i];
            if (existing) { cancelAnimationFrame(existing); animsRef.current[i] = null; }
          });
          doneRef.current = [false, false, false];
          currentRef.current = 0;
          setDone([false, false, false]);
          setCurrent(0);
          [0, 1, 2].forEach((i) => setDrawProgress(i, 0));
          phase = 4;
        }
      }
      frameRef.current = requestAnimationFrame(loopTick);
    }
    frameRef.current = requestAnimationFrame(loopTick);
    return () => cancelAnimationFrame(frameRef.current);
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);

  function onKeyDown(e: { key: string; preventDefault: () => void }): void {
    if (e.key === "ArrowRight") { stopDemo(); complete(); e.preventDefault(); }
    else if (e.key === "ArrowLeft") { stopDemo(); back(); e.preventDefault(); }
  }

  const allDone = done[current] || (current >= STEP_COUNT - 1 && done[STEP_COUNT - 1]);
  const statusText = allDone ? STATUS_ALL_DONE : STATUS_TEXTS[current];

  return (
    <main className={styles.stage}>
      <div className={styles.cm} onKeyDown={onKeyDown} ref={(el: HTMLDivElement | null) => { rootRef.current = el; }}>
        <ol className={styles.row} role="list" aria-label="신청서 제출 단계">
          {LABELS.map((label, i) => (
            <li key={label} style={{ display: "contents" }}>
              <div className={styles.node}>
                <span className={[styles.circle, i === current && !done[i] ? styles.circleActive : "", done[i] ? styles.circleDone : ""].join(" ")} ref={(el: HTMLSpanElement | null) => { circleRefs.current[i] = el; }}>
                  <span className={styles.digit} ref={(el: HTMLSpanElement | null) => { digitRefs.current[i] = el; }}>{i + 1}</span>
                  <svg className={styles.check} viewBox="0 0 24 24" aria-hidden="true" focusable="false">
                    <path className={styles.checkPath} ref={(el: SVGPathElement | null) => { pathRefs.current[i] = el; }} d="M5 12.5 L10 17.5 L19 6.5" />
                  </svg>
                </span>
                <span className={styles.label}>{label}</span>
              </div>
              {i < STEP_COUNT - 1 && <div className={styles.connector} />}
            </li>
          ))}
        </ol>
        <p className={styles.status} aria-live="polite">{statusText}</p>
        <div className={styles.controls}>
          <button type="button" className={styles.btn} disabled={current === 0} onClick={() => { stopDemo(); back(); }}>이전</button>
          <button type="button" className={[styles.btn, styles.btnPrimary].join(" ")} disabled={done[STEP_COUNT - 1]} onClick={() => { stopDemo(); complete(); }}>완료</button>
        </div>
      </div>
    </main>
  );
}