04周囲進行 — ボタンを囲む周囲の進行の値が決まった時間の間に減っていくボタン

<main class="stage">
<div class="ctaprc is-demo" id="ctaprc">
  <div class="ctaprc__panel">
    <div class="ctaprc__wrap">
      <svg class="ctaprc__ring" viewBox="0 0 84 84" id="ctaprcSvg">
        <circle class="ctaprc__track" cx="42" cy="42" r="38"></circle>
        <circle class="ctaprc__bar" id="ctaprcBar" cx="42" cy="42" r="38"></circle>
      </svg>
      <button class="ctaprc__btn" id="ctaprcBtn" type="button">次のステップ</button>
    </div>
    <span class="ctaprc__hint">クリックすると1.5秒後に自動で次のステップに進みます</span>
  </div>
</div>
</main>

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

// 계산 겹(둘레·dashoffset 산술)은 JS 에 있다 — 여기는 정적 배치만.
@include stage($stage-yellow);

.stage { position: relative; }

.ctaprc__panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: $sp-4;
  padding: $sp-5;
  border-radius: $r-card;
  background: $stage-paper;
}

.ctaprc__wrap {
  position: relative;
  width: 92px;
  height: 92px;
  display: grid;
  place-items: center;
}

.ctaprc__ring {
  position: absolute;
  inset: 0;
  width: 92px;
  height: 92px;
  transform: rotate(-90deg);
}

.ctaprc__track {
  fill: none;
  stroke: rgba($subject-ink, .12);
  stroke-width: 6;
}

.ctaprc__bar {
  fill: none;
  stroke: $subject-blue-deep;
  stroke-width: 6;
  stroke-linecap: round;
}

.ctaprc__btn {
  position: relative;
  border: 0;
  border-radius: $r-pill;
  background: $subject-blue-deep;
  color: $subject-cream;
  font-family: inherit;
  font-weight: 700;
  font-size: 12px;
  width: 68px;
  height: 68px;
  cursor: pointer;
}

.ctaprc__hint {
  color: rgba($subject-ink, .72);
  font-size: 12px;
  text-align: center;
}

@media (max-width: 340px) {
  .ctaprc__panel { padding: $sp-4; gap: $sp-3; }
  .ctaprc__wrap { width: 76px; height: 76px; }
  .ctaprc__ring { width: 76px; height: 76px; }
  .ctaprc__btn { width: 56px; height: 56px; font-size: 11px; }
}

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

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffd23f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.stage {
  position: relative;
}

.ctaprc__panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  padding: 20px;
  border-radius: 16px;
  background: #ffffff;
}

.ctaprc__wrap {
  position: relative;
  width: 92px;
  height: 92px;
  display: grid;
  place-items: center;
}

.ctaprc__ring {
  position: absolute;
  inset: 0;
  width: 92px;
  height: 92px;
  transform: rotate(-90deg);
}

.ctaprc__track {
  fill: none;
  stroke: rgba(23, 20, 26, 0.12);
  stroke-width: 6;
}

.ctaprc__bar {
  fill: none;
  stroke: #0a4fe8;
  stroke-width: 6;
  stroke-linecap: round;
}

.ctaprc__btn {
  position: relative;
  border: 0;
  border-radius: 999px;
  background: #0a4fe8;
  color: #fff7e6;
  font-family: inherit;
  font-weight: 700;
  font-size: 12px;
  width: 68px;
  height: 68px;
  cursor: pointer;
}

.ctaprc__hint {
  color: rgba(23, 20, 26, 0.72);
  font-size: 12px;
  text-align: center;
}

@media (max-width: 340px) {
  .ctaprc__panel {
    padding: 16px;
    gap: 12px;
  }
  .ctaprc__wrap {
    width: 76px;
    height: 76px;
  }
  .ctaprc__ring {
    width: 76px;
    height: 76px;
  }
  .ctaprc__btn {
    width: 56px;
    height: 56px;
    font-size: 11px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .ctaprc__ring {
    transition: none !important;
  }
}

(function () {
  var root = document.getElementById('ctaprc');
  var btn = document.getElementById('ctaprcBtn');
  var bar = document.getElementById('ctaprcBar');

  // 계산 겹: 반지름(r)으로 둘레(circumference = 2*PI*r)를 구하고, 남은 시간 비율(progress)을
  // stroke-dashoffset = circumference * (1 - progress) 산술로 매 프레임 다시 그린다.
  var R = 38;
  var CIRC = 2 * Math.PI * R;
  bar.style.strokeDasharray = CIRC.toFixed(2);
  var DURATION = 1500;
  var raf = null, startT = 0, running = false;

  function frame(now) {
    var t = now - startT;
    var progress = Math.min(1, t / DURATION);
    var offset = CIRC * (1 - progress);
    bar.style.strokeDashoffset = offset.toFixed(2);
    if (progress < 1) {
      raf = requestAnimationFrame(frame);
    } else {
      running = false; raf = null;
      btn.textContent = '完了しました';
      setTimeout(function () { btn.textContent = '次のステップ'; bar.style.strokeDashoffset = CIRC.toFixed(2); }, 500);
    }
  }
  function startCountdown() {
    if (running) { return; }
    running = true;
    startT = performance.now();
    raf = requestAnimationFrame(frame);
  }

  function wireReal() {
    btn.addEventListener('click', function () { root.classList.remove('is-demo'); stopAutoplay(); startCountdown(); });
  }
  wireReal();
  bar.style.strokeDashoffset = CIRC.toFixed(2);

  var autoplayTimer = null;
  function stopAutoplay() { if (autoplayTimer) { clearInterval(autoplayTimer); autoplayTimer = null; } }
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  if (!reduce) { startCountdown(); autoplayTimer = setInterval(startCountdown, 2000); }
})();

import { useEffect, useRef } from "react";
import styles from "./CtaBtnProgressRingCountdown.module.scss";

export type CtaBtnProgressRingCountdownProps = {
  color?: string;
};

export default function CtaBtnProgressRingCountdown({
  color = "#0a4fe8",
}: CtaBtnProgressRingCountdownProps) {
  const rootRef = useRef<HTMLDivElement | null>(null);

  useEffect(() => {
    const root = rootRef.current;
    if (!root) return;
    const btn = root.querySelector<HTMLButtonElement>(`.${styles.btn}`);
    const bar = root.querySelector<SVGCircleElement>(`.${styles.bar}`);
    if (!btn || !bar) return;

    // 계산 겹: 반지름(r)으로 둘레(circumference = 2*PI*r)를 구하고, 남은 시간 비율(progress)을
    // stroke-dashoffset = circumference * (1 - progress) 산술로 매 프레임 다시 그린다.
    const R = 38;
    const CIRC = 2 * Math.PI * R;
    bar.style.strokeDasharray = CIRC.toFixed(2);
    bar.style.strokeDashoffset = CIRC.toFixed(2);
    const DURATION = 1500;
    let raf: number | null = null;
    let startT = 0;
    let running = false;

    function frame(now: number) {
      const t = now - startT;
      const progress = Math.min(1, t / DURATION);
      const offset = CIRC * (1 - progress);
      bar!.style.strokeDashoffset = offset.toFixed(2);
      if (progress < 1) {
        raf = requestAnimationFrame(frame);
      } else {
        running = false; raf = null;
        btn!.textContent = "완료됨";
        window.setTimeout(() => { btn!.textContent = "다음 단계"; bar!.style.strokeDashoffset = CIRC.toFixed(2); }, 500);
      }
    }
    function startCountdown() {
      if (running) return;
      running = true;
      startT = performance.now();
      raf = requestAnimationFrame(frame);
    }

    function onClick() { stopAutoplay(); startCountdown(); }
    btn.addEventListener("click", onClick);

    let autoplayTimer: number | null = null;
    function stopAutoplay() { if (autoplayTimer !== null) { window.clearInterval(autoplayTimer); autoplayTimer = null; } }
    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    if (!reduce) { startCountdown(); autoplayTimer = window.setInterval(startCountdown, 2000); }

    return () => {
      stopAutoplay();
      if (raf !== null) { cancelAnimationFrame(raf); }
      btn.removeEventListener("click", onClick);
    };
  }, []);

  return (
    <div ref={rootRef} className={styles.stage}>
      <div className={styles.panel}>
        <div className={styles.wrap}>
          <svg className={styles.ring} viewBox="0 0 84 84">
            <circle className={styles.track} cx={42} cy={42} r={38} />
            <circle className={styles.bar} cx={42} cy={42} r={38} style={{ stroke: color }} />
          </svg>
          <button className={styles.btn} type="button" style={{ background: color }}>다음 단계</button>
        </div>
        <span className={styles.hint}>클릭하면 1.5초 뒤 자동으로 다음 단계로 넘어갑니다</span>
      </div>
    </div>
  );
}