08클릭 좌표 값이 번지는 원형 마스크 패널

<main class="stage">
<div class="mr is-demo" id="mr">
  <div class="mr__tabs" role="tablist" aria-label="기능 탭">
    <button type="button" class="mr__tab is-active" role="tab" id="mr-tab-0" aria-selected="true" aria-controls="mr-panel-0" data-idx="0">속도</button>
    <button type="button" class="mr__tab" role="tab" id="mr-tab-1" aria-selected="false" aria-controls="mr-panel-1" data-idx="1" tabindex="-1">보안</button>
    <button type="button" class="mr__tab" role="tab" id="mr-tab-2" aria-selected="false" aria-controls="mr-panel-2" data-idx="2" tabindex="-1">협업</button>
  </div>
  <div class="mr__wrap" id="mrWrap">
    <div class="mr__panel is-active" id="mr-panel-0" role="tabpanel" aria-labelledby="mr-tab-0" tabindex="0"><span class="mr__num">01</span><p class="mr__line">응답 속도 120ms</p></div>
    <div class="mr__panel" id="mr-panel-1" role="tabpanel" aria-labelledby="mr-tab-1" tabindex="0" hidden><span class="mr__num">02</span><p class="mr__line">2단계 인증 지원</p></div>
    <div class="mr__panel" id="mr-panel-2" role="tabpanel" aria-labelledby="mr-tab-2" tabindex="0" hidden><span class="mr__num">03</span><p class="mr__line">실시간 공동 편집</p></div>
  </div>
  <p class="mr__meta">반경 <b id="mrR">0</b>px</p>
</div>
</main>

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

// 계산 겹: index.html 의 select() 가 클릭(또는 키보드 이동)된 탭 라벨의 중심 좌표를 clip-path circle() 의
// 중심점으로 쓰고, 반경 목표값은 Math.hypot(wrap.width, wrap.height) 로 구한 패널 대각선 길이다.
@include stage($stage-paper);

.mr { width: min(100%, 300px); min-width: 0; display: flex; flex-direction: column; gap: $sp-3; }
.mr__tabs { display: flex; gap: $sp-1; background: rgba($subject-blue-deep, .08); padding: $sp-1; border-radius: $r-pill; }
.mr__tab {
  flex: 1 1 0; border: none; background: transparent; border-radius: $r-pill; cursor: pointer;
  padding: $sp-2 $sp-2; font-size: 11px; font-weight: 700; color: rgba($subject-ink, .64);
}
.mr__tab.is-active { background: $subject-blue-deep; color: $subject-cream; }
.mr__tab:focus-visible { outline: 2px solid $subject-blue-deep; outline-offset: 2px; }

.mr__wrap { position: relative; min-width: 0; height: 140px; border-radius: $r-card; background: $subject-cream; overflow: hidden; box-shadow: 0 6px 18px rgba($subject-ink, .1); }
.mr__panel {
  position: absolute; inset: 0; box-sizing: border-box; padding: $sp-4;
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: $sp-2;
  opacity: 0; pointer-events: none;
}
.mr__panel.is-active { opacity: 1; pointer-events: auto; z-index: 1; }
.mr__panel.is-front { opacity: 1; pointer-events: auto; z-index: 2; transition: clip-path $dur-enter $ease-out; }
.mr__num { font-size: 30px; font-weight: 800; color: $subject-blue-deep; }
.mr__line { margin: 0; font-size: 12px; color: rgba($subject-ink, .72); }

.mr__meta { margin: 0; font-size: 11px; color: rgba($subject-ink, .6); text-align: center; }
.mr__meta b { color: $subject-blue-deep; font-weight: 700; }

@media (max-width: 340px) {
  .mr { width: 100%; gap: $sp-2; }
  .mr__tab { padding: $sp-1 $sp-2; }
  .mr__wrap { height: 96px; }
  .mr__num { font-size: 24px; }
}

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

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

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

.mr {
  width: min(100%, 300px);
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.mr__tabs {
  display: flex;
  gap: 4px;
  background: rgba(10, 79, 232, 0.08);
  padding: 4px;
  border-radius: 999px;
}

.mr__tab {
  flex: 1 1 0;
  border: none;
  background: transparent;
  border-radius: 999px;
  cursor: pointer;
  padding: 8px 8px;
  font-size: 11px;
  font-weight: 700;
  color: rgba(23, 20, 26, 0.64);
}

.mr__tab.is-active {
  background: #0a4fe8;
  color: #fff7e6;
}

.mr__tab:focus-visible {
  outline: 2px solid #0a4fe8;
  outline-offset: 2px;
}

.mr__wrap {
  position: relative;
  min-width: 0;
  height: 140px;
  border-radius: 16px;
  background: #fff7e6;
  overflow: hidden;
  box-shadow: 0 6px 18px rgba(23, 20, 26, 0.1);
}

.mr__panel {
  position: absolute;
  inset: 0;
  box-sizing: border-box;
  padding: 16px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  opacity: 0;
  pointer-events: none;
}

.mr__panel.is-active {
  opacity: 1;
  pointer-events: auto;
  z-index: 1;
}

.mr__panel.is-front {
  opacity: 1;
  pointer-events: auto;
  z-index: 2;
  transition: clip-path 600ms ease-out;
}

.mr__num {
  font-size: 30px;
  font-weight: 800;
  color: #0a4fe8;
}

.mr__line {
  margin: 0;
  font-size: 12px;
  color: rgba(23, 20, 26, 0.72);
}

.mr__meta {
  margin: 0;
  font-size: 11px;
  color: rgba(23, 20, 26, 0.6);
  text-align: center;
}

.mr__meta b {
  color: #0a4fe8;
  font-weight: 700;
}

@media (max-width: 340px) {
  .mr {
    width: 100%;
    gap: 8px;
  }
  .mr__tab {
    padding: 4px 8px;
  }
  .mr__wrap {
    height: 96px;
  }
  .mr__num {
    font-size: 24px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .mr__panel.is-front {
    transition: none;
  }
}

(function () {
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  var COUNT = 3;
  var HOLD_MS = 900;

  var root = document.getElementById('mr');
  var wrap = document.getElementById('mrWrap');
  var rEl = document.getElementById('mrR');
  var tabs = [0, 1, 2].map(function (i) { return document.getElementById('mr-tab-' + i); });
  var panels = [0, 1, 2].map(function (i) { return document.getElementById('mr-panel-' + i); });

  var isDemo = true;
  var active = 0;
  var busy = false;

  function human() {
    if (isDemo) { root.classList.remove('is-demo'); isDemo = false; }
  }

  function select(idx) {
    if (idx === active || busy) return;
    busy = true;
    var tabRect = tabs[idx].getBoundingClientRect();
    var wrapRect = wrap.getBoundingClientRect();
    var cx = tabRect.left + tabRect.width / 2 - wrapRect.left; // 계산 겹: 탭 라벨 중심 좌표 → 마스크 중심
    var cy = tabRect.top + tabRect.height / 2 - wrapRect.top;
    var r = Math.hypot(wrapRect.width, wrapRect.height); // 계산 겹: 패널 대각선 길이 = 반경 목표값

    var incoming = panels[idx];
    var outgoing = panels[active];

    incoming.style.transition = 'none';
    incoming.style.clipPath = 'circle(0px at ' + cx.toFixed(1) + 'px ' + cy.toFixed(1) + 'px)';
    incoming.removeAttribute('hidden');
    incoming.classList.add('is-front');
    incoming.getBoundingClientRect();
    incoming.style.transition = '';
    rEl.textContent = '0';

    tabs[active].classList.remove('is-active');
    tabs[active].setAttribute('aria-selected', 'false');
    tabs[active].setAttribute('tabindex', '-1');
    tabs[idx].classList.add('is-active');
    tabs[idx].setAttribute('aria-selected', 'true');
    tabs[idx].setAttribute('tabindex', '0');

    requestAnimationFrame(function () {
      incoming.style.clipPath = 'circle(' + r.toFixed(1) + 'px at ' + cx.toFixed(1) + 'px ' + cy.toFixed(1) + 'px)';
      rEl.textContent = String(Math.round(r));
    });

    function onEnd(e) {
      if (e.propertyName !== 'clip-path') return;
      incoming.removeEventListener('transitionend', onEnd);
      incoming.classList.add('is-active');
      incoming.classList.remove('is-front');
      incoming.style.clipPath = 'none';
      outgoing.classList.remove('is-active');
      outgoing.setAttribute('hidden', '');
      active = idx;
      busy = false;
    }
    incoming.addEventListener('transitionend', onEnd);
  }

  tabs.forEach(function (t, i) {
    t.addEventListener('click', function () { human(); select(i); });
  });

  root.addEventListener('keydown', function (e) {
    var idx = tabs.indexOf(document.activeElement);
    if (idx === -1) return;
    var next = null;
    if (e.key === 'ArrowRight') next = (idx + 1) % COUNT;
    else if (e.key === 'ArrowLeft') next = (idx - 1 + COUNT) % COUNT;
    else if (e.key === 'Home') next = 0;
    else if (e.key === 'End') next = COUNT - 1;
    if (next === null) return;
    e.preventDefault();
    human();
    tabs[next].focus({ preventScroll: true });
    select(next);
  });

  function loop() {
    if (!isDemo) return;
    select((active + 1) % COUNT);
    window.setTimeout(loop, HOLD_MS);
  }

  if (!reduce) {
    window.setTimeout(loop, HOLD_MS);
  } else {
    root.classList.remove('is-demo');
  }
})();

// TabMaskRevealRadial — vanilla 판(run/394/demo/08-tab-panel-mask-reveal-radial/index.html) 의 React 포트.
// select() 가 클릭(또는 키보드 이동)된 탭 라벨의 중심 좌표를 clip-path circle() 의 중심점으로 쓰고,
// 반경 목표값은 Math.hypot(wrap.width, wrap.height) 로 구한 패널 대각선 길이다.
import { useEffect, useRef } from "react";
import styles from "./TabMaskRevealRadial.module.scss";

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

const HOLD_MS = 900;
const COUNT = 3;

export default function TabMaskRevealRadial() {
  const rootRef = useRef(null) as unknown as Box<HTMLDivElement>;
  const wrapRef = useRef(null) as unknown as Box<HTMLDivElement>;
  const rEl = useRef(null) as unknown as Box<HTMLElement>;
  const tabRefs = useRef([null, null, null]) as unknown as Box<(HTMLButtonElement | null)[]>;
  const panelRefs = useRef([null, null, null]) as unknown as Box<(HTMLDivElement | null)[]>;
  const timerRef = useRef(0) as unknown as Box<number>;

  useEffect(() => {
    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    let isDemo = true;
    let active = 0;
    let busy = false;

    function human() {
      if (isDemo) { rootRef.current?.classList.remove(styles.isDemo); isDemo = false; }
    }

    function select(idx: number) {
      if (idx === active || busy) return;
      const wrap = wrapRef.current, tab = tabRefs.current[idx];
      const incoming = panelRefs.current[idx], outgoing = panelRefs.current[active];
      if (!wrap || !tab || !incoming || !outgoing) return;
      busy = true;

      const tabRect = tab.getBoundingClientRect();
      const wrapRect = wrap.getBoundingClientRect();
      const cx = tabRect.left + tabRect.width / 2 - wrapRect.left; // 계산 겹: 탭 라벨 중심 좌표 → 마스크 중심
      const cy = tabRect.top + tabRect.height / 2 - wrapRect.top;
      const r = Math.hypot(wrapRect.width, wrapRect.height); // 계산 겹: 패널 대각선 길이 = 반경 목표값

      incoming.style.transition = "none";
      incoming.style.clipPath = "circle(0px at " + cx.toFixed(1) + "px " + cy.toFixed(1) + "px)";
      incoming.removeAttribute("hidden");
      incoming.classList.add(styles.isFront);
      incoming.getBoundingClientRect();
      incoming.style.transition = "";
      if (rEl.current) rEl.current.textContent = "0";

      const prevTab = tabRefs.current[active], nextTab = tabRefs.current[idx];
      prevTab?.classList.remove(styles.isActive);
      prevTab?.setAttribute("aria-selected", "false");
      prevTab?.setAttribute("tabindex", "-1");
      nextTab?.classList.add(styles.isActive);
      nextTab?.setAttribute("aria-selected", "true");
      nextTab?.setAttribute("tabindex", "0");

      requestAnimationFrame(() => {
        incoming.style.clipPath = "circle(" + r.toFixed(1) + "px at " + cx.toFixed(1) + "px " + cy.toFixed(1) + "px)";
        if (rEl.current) rEl.current.textContent = String(Math.round(r));
      });

      function onEnd(e: TransitionEvent) {
        if (e.propertyName !== "clip-path") return;
        incoming!.removeEventListener("transitionend", onEnd as EventListener);
        incoming!.classList.add(styles.isActive);
        incoming!.classList.remove(styles.isFront);
        incoming!.style.clipPath = "none";
        outgoing!.classList.remove(styles.isActive);
        outgoing!.setAttribute("hidden", "");
        active = idx;
        busy = false;
      }
      incoming.addEventListener("transitionend", onEnd as EventListener);
    }

    function onKeydown(e: KeyboardEvent) {
      const idx = tabRefs.current.indexOf(document.activeElement as HTMLButtonElement);
      if (idx === -1) return;
      let next: number | null = null;
      if (e.key === "ArrowRight") next = (idx + 1) % COUNT;
      else if (e.key === "ArrowLeft") next = (idx - 1 + COUNT) % COUNT;
      else if (e.key === "Home") next = 0;
      else if (e.key === "End") next = COUNT - 1;
      if (next === null) return;
      e.preventDefault();
      human();
      tabRefs.current[next]?.focus({ preventScroll: true });
      select(next);
    }

    function onTabClick(i: number) { return () => { human(); select(i); }; }
    const clickHandlers = [0, 1, 2].map(onTabClick);
    tabRefs.current.forEach((t, i) => t?.addEventListener("click", clickHandlers[i]));
    rootRef.current?.addEventListener("keydown", onKeydown);

    function loop() {
      if (!isDemo) return;
      select((active + 1) % COUNT);
      timerRef.current = window.setTimeout(loop, HOLD_MS);
    }

    if (!reduce) {
      timerRef.current = window.setTimeout(loop, HOLD_MS);
    } else {
      rootRef.current?.classList.remove(styles.isDemo);
    }

    return () => {
      window.clearTimeout(timerRef.current);
      tabRefs.current.forEach((t, i) => t?.removeEventListener("click", clickHandlers[i]));
      rootRef.current?.removeEventListener("keydown", onKeydown);
    };
  }, []);

  const feats = [
    { name: "속도", num: "01", line: "응답 속도 120ms" },
    { name: "보안", num: "02", line: "2단계 인증 지원" },
    { name: "협업", num: "03", line: "실시간 공동 편집" },
  ];

  return (
    <main className={styles.stage}>
      <div className={styles.mr + " " + styles.isDemo} ref={rootRef}>
        <div className={styles.tabs} role="tablist" aria-label="기능 탭">
          {feats.map((f, i) => (
            <button
              key={f.name}
              type="button"
              className={styles.tab + (i === 0 ? " " + styles.isActive : "")}
              role="tab"
              aria-selected={i === 0 ? "true" : "false"}
              tabIndex={i === 0 ? 0 : -1}
              ref={(el: HTMLButtonElement | null) => { tabRefs.current[i] = el; }}
            >{f.name}</button>
          ))}
        </div>
        <div className={styles.wrap} ref={wrapRef}>
          {feats.map((f, i) => (
            <div
              key={f.name}
              className={styles.panel + (i === 0 ? " " + styles.isActive : "")}
              role="tabpanel"
              tabIndex={0}
              hidden={i !== 0}
              ref={(el: HTMLDivElement | null) => { panelRefs.current[i] = el; }}
            >
              <span className={styles.num}>{f.num}</span>
              <p className={styles.line}>{f.line}</p>
            </div>
          ))}
        </div>
        <p className={styles.meta}>
          반경 <b ref={rEl}>0</b>px
        </p>
      </div>
    </main>
  );
}