02中間階層をたたむメニュー

<main class="stage">
  <div class="cm is-demo">
    <nav aria-label="パンくずリスト">
      <ol class="cm__list">
        <li><a href="#">ホーム</a></li>
        <li class="cm__slot" id="cm-slot">
          <button class="cm__dots" id="cm-btn" type="button" aria-expanded="false" aria-controls="cm-menu" aria-label="隠れた階層を表示">
            <svg viewBox="0 0 256 256" width="16" height="16" aria-hidden="true"><g fill="currentColor"><path d="M240 96v64a16 16 0 0 1-16 16H32a16 16 0 0 1-16-16V96a16 16 0 0 1 16-16h192a16 16 0 0 1 16 16" opacity=".2"/><path d="M140 128a12 12 0 1 1-12-12a12 12 0 0 1 12 12m56-12a12 12 0 1 0 12 12a12 12 0 0 0-12-12m-136 0a12 12 0 1 0 12 12a12 12 0 0 0-12-12"/></g></svg>
          </button>
          <ul class="cm__menu" id="cm-menu">
            <li><a href="#"><svg viewBox="0 0 256 256" width="14" height="14" aria-hidden="true"><g fill="currentColor"><path d="M128 80H32V56a8 8 0 0 1 8-8h52.69a8 8 0 0 1 5.65 2.34Z" opacity=".2"/><path d="M216 72h-84.69L104 44.69A15.86 15.86 0 0 0 92.69 40H40a16 16 0 0 0-16 16v144.62A15.4 15.4 0 0 0 39.38 216h177.51A15.13 15.13 0 0 0 232 200.89V88a16 16 0 0 0-16-16M92.69 56l16 16H40V56ZM216 200H40V88h176Z"/></g></svg>電子機器</a></li>
            <li><a href="#"><svg viewBox="0 0 256 256" width="14" height="14" aria-hidden="true"><g fill="currentColor"><path d="M128 80H32V56a8 8 0 0 1 8-8h52.69a8 8 0 0 1 5.65 2.34Z" opacity=".2"/><path d="M216 72h-84.69L104 44.69A15.86 15.86 0 0 0 92.69 40H40a16 16 0 0 0-16 16v144.62A15.4 15.4 0 0 0 39.38 216h177.51A15.13 15.13 0 0 0 232 200.89V88a16 16 0 0 0-16-16M92.69 56l16 16H40V56ZM216 200H40V88h176Z"/></g></svg>コンピューター</a></li>
          </ul>
        </li>
        <li><a href="#">ノートPC</a></li>
        <li><span class="cm__cur" aria-current="page">13インチ ゲーミング</span></li>
      </ol>
    </nav>
  </div>
</main>

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

$duration: $dur-quick;
$easing: $ease-spring;
$color: $subject-blue;

@include stage($stage-ink);

// 절대배치 목록은 부모 높이 계산에서 빠지지만 scrollHeight 엔 잡힌다 →
// 뿌리에 열린 목록 높이(8px 띄움 + 64px 목록)만큼 자리를 미리 확보한다 (BD9)
.cm {
  padding-bottom: 72px;
  user-select: none;
  -webkit-user-select: none;
}

.cm__list {
  display: flex;
  align-items: center;
  flex-wrap: nowrap;
  gap: $sp-2;
  margin: 0;
  padding: 0;
  list-style: none;
  white-space: nowrap;
  font-size: clamp(11px, 3.2vw, 13px);
  line-height: 20px;
  font-weight: 600;
}
.cm__list > li { display: inline-flex; align-items: center; gap: $sp-2; }
.cm__list > li + li::before {
  content: "\203A";
  display: inline-flex;
  justify-content: center;
  width: 8px;
  color: rgba($subject-cream, .45);
}
.cm__list a { color: rgba($subject-cream, .82); text-decoration: none; border-radius: $r-xs; }
.cm__list a:hover { color: $subject-cream; text-decoration: underline; text-underline-offset: 4px; }
.cm__list a:focus-visible { outline: 2px solid $subject-cream; outline-offset: 2px; }
.cm__cur { color: $subject-cream; font-weight: 800; }

.cm__slot { position: relative; }
.cm__dots {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 24px;
  padding: 0;
  border: 0;
  border-radius: $r-sm;
  background: rgba($subject-cream, .14);
  color: $subject-cream;
  cursor: pointer;
  transition: transform $duration $easing, background-color $duration $easing;
}
.cm__dots:hover { background: rgba($subject-cream, .26); }
.cm__dots:focus-visible { outline: 2px solid $subject-cream; outline-offset: 2px; }
.cm__slot.is-open .cm__dots { background: $color; }

.cm__menu {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  z-index: 2;
  min-width: 132px;
  margin: 0;
  padding: $sp-1;
  list-style: none;
  border-radius: $r-control;
  background: $subject-cream;
  box-shadow: $shadow-raised;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  transition: opacity $duration $easing, transform $duration $easing, visibility 0s linear $duration;
}
.cm__slot.is-open .cm__menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  transition: opacity $duration $easing, transform $duration $easing, visibility 0s linear 0s;
}
.cm__menu li { display: block; }
.cm__menu a {
  display: flex;
  align-items: center;
  gap: $sp-2;
  padding: $sp-1 $sp-2;
  border-radius: $r-sm;
  color: $subject-ink;
  text-decoration: none;
  font-size: 12px;
  line-height: 20px;
  font-weight: 600;
  white-space: nowrap;
}
.cm__menu a:hover { background-color: rgba($color, .18); color: $subject-ink; text-decoration: none; }
.cm__menu a:focus-visible { outline: 2px solid $color; outline-offset: -2px; }
.cm__menu svg { flex: none; color: rgba($subject-ink, .55); }

// ── 자동 루프: 눌림 → 목록이 translateY+opacity 로 내려옴 → 유지(hover 표시가 steps 로 옮겨감) → 접힘 ──
.cm.is-demo .cm__dots {
  animation-name: cm-press;
  animation-duration: $dur-loop;
  animation-timing-function: $easing;
  animation-iteration-count: infinite;
}
@keyframes cm-press {
  0%, 4%    { transform: scale(1); }
  10%       { transform: scale(.84); }
  16%, 100% { transform: scale(1); }
}
// 나타남/사라짐은 steps(1, end) 로 한 프레임에 컷하고, 움직임은 translateY 가 맡는다.
// opacity 를 서서히 올리면 poster 가 반투명하게 뜬 흐린 패널이 된다 (blog-demo 실패표)
.cm.is-demo .cm__menu {
  visibility: visible;
  animation-name: cm-cut, cm-slide;
  animation-duration: $dur-loop, $dur-loop;
  animation-timing-function: steps(1, end), $easing;
  animation-iteration-count: infinite, infinite;
}
@keyframes cm-cut {
  0%        { opacity: 0; }
  14%       { opacity: 1; }
  84%, 100% { opacity: 0; }
}
@keyframes cm-slide {
  0%, 14%   { transform: translateY(-10px); }
  42%, 70%  { transform: translateY(0); }
  84%, 100% { transform: translateY(-10px); }
}
// hover 표시는 한 프레임에 컷으로 옮긴다 — 겹치면 poster 에 두 줄이 동시에 눌린 것처럼 보인다
.cm.is-demo .cm__menu li:nth-child(1) a,
.cm.is-demo .cm__menu li:nth-child(2) a {
  animation-duration: $dur-loop;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}
.cm.is-demo .cm__menu li:nth-child(1) a { animation-name: cm-hi1; }
.cm.is-demo .cm__menu li:nth-child(2) a { animation-name: cm-hi2; }
@keyframes cm-hi1 { 0% { background-color: rgba($color, 0); } 46% { background-color: rgba($color, .18); } 60%, 100% { background-color: rgba($color, 0); } }
@keyframes cm-hi2 { 0% { background-color: rgba($color, 0); } 60% { background-color: rgba($color, .18); } 74%, 100% { background-color: rgba($color, 0); } }

@media (max-width: 340px) {
  .cm { padding-bottom: 68px; }
  .cm__menu { min-width: 120px; }
  .cm__dots { width: 26px; }
}

@media (prefers-reduced-motion: reduce) {
  .cm.is-demo .cm__dots,
  .cm.is-demo .cm__menu,
  .cm.is-demo .cm__menu a { animation: none !important; }
  .cm.is-demo .cm__menu { opacity: 1; transform: none; }
  .cm__dots, .cm__menu { transition: none; }
}

@charset "UTF-8";
html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.cm {
  padding-bottom: 72px;
  user-select: none;
  -webkit-user-select: none;
}

.cm__list {
  display: flex;
  align-items: center;
  flex-wrap: nowrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  white-space: nowrap;
  font-size: clamp(11px, 3.2vw, 13px);
  line-height: 20px;
  font-weight: 600;
}

.cm__list > li {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.cm__list > li + li::before {
  content: "›";
  display: inline-flex;
  justify-content: center;
  width: 8px;
  color: rgba(255, 247, 230, 0.45);
}

.cm__list a {
  color: rgba(255, 247, 230, 0.82);
  text-decoration: none;
  border-radius: 4px;
}

.cm__list a:hover {
  color: #fff7e6;
  text-decoration: underline;
  text-underline-offset: 4px;
}

.cm__list a:focus-visible {
  outline: 2px solid #fff7e6;
  outline-offset: 2px;
}

.cm__cur {
  color: #fff7e6;
  font-weight: 800;
}

.cm__slot {
  position: relative;
}

.cm__dots {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 24px;
  padding: 0;
  border: 0;
  border-radius: 8px;
  background: rgba(255, 247, 230, 0.14);
  color: #fff7e6;
  cursor: pointer;
  transition: transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1), background-color 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.cm__dots:hover {
  background: rgba(255, 247, 230, 0.26);
}

.cm__dots:focus-visible {
  outline: 2px solid #fff7e6;
  outline-offset: 2px;
}

.cm__slot.is-open .cm__dots {
  background: #2f6df6;
}

.cm__menu {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  z-index: 2;
  min-width: 132px;
  margin: 0;
  padding: 4px;
  list-style: none;
  border-radius: 12px;
  background: #fff7e6;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  transition: opacity 220ms cubic-bezier(0.2, 0.8, 0.2, 1), transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1), visibility 0s linear 220ms;
}

.cm__slot.is-open .cm__menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  transition: opacity 220ms cubic-bezier(0.2, 0.8, 0.2, 1), transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1), visibility 0s linear 0s;
}

.cm__menu li {
  display: block;
}

.cm__menu a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 4px 8px;
  border-radius: 8px;
  color: #17141a;
  text-decoration: none;
  font-size: 12px;
  line-height: 20px;
  font-weight: 600;
  white-space: nowrap;
}

.cm__menu a:hover {
  background-color: rgba(47, 109, 246, 0.18);
  color: #17141a;
  text-decoration: none;
}

.cm__menu a:focus-visible {
  outline: 2px solid #2f6df6;
  outline-offset: -2px;
}

.cm__menu svg {
  flex: none;
  color: rgba(23, 20, 26, 0.55);
}

.cm.is-demo .cm__dots {
  animation-name: cm-press;
  animation-duration: 2s;
  animation-timing-function: cubic-bezier(0.2, 0.8, 0.2, 1);
  animation-iteration-count: infinite;
}

@keyframes cm-press {
  0%, 4% {
    transform: scale(1);
  }
  10% {
    transform: scale(0.84);
  }
  16%, 100% {
    transform: scale(1);
  }
}
.cm.is-demo .cm__menu {
  visibility: visible;
  animation-name: cm-cut, cm-slide;
  animation-duration: 2s, 2s;
  animation-timing-function: steps(1, end), cubic-bezier(0.2, 0.8, 0.2, 1);
  animation-iteration-count: infinite, infinite;
}

@keyframes cm-cut {
  0% {
    opacity: 0;
  }
  14% {
    opacity: 1;
  }
  84%, 100% {
    opacity: 0;
  }
}
@keyframes cm-slide {
  0%, 14% {
    transform: translateY(-10px);
  }
  42%, 70% {
    transform: translateY(0);
  }
  84%, 100% {
    transform: translateY(-10px);
  }
}
.cm.is-demo .cm__menu li:nth-child(1) a,
.cm.is-demo .cm__menu li:nth-child(2) a {
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}

.cm.is-demo .cm__menu li:nth-child(1) a {
  animation-name: cm-hi1;
}

.cm.is-demo .cm__menu li:nth-child(2) a {
  animation-name: cm-hi2;
}

@keyframes cm-hi1 {
  0% {
    background-color: rgba(47, 109, 246, 0);
  }
  46% {
    background-color: rgba(47, 109, 246, 0.18);
  }
  60%, 100% {
    background-color: rgba(47, 109, 246, 0);
  }
}
@keyframes cm-hi2 {
  0% {
    background-color: rgba(47, 109, 246, 0);
  }
  60% {
    background-color: rgba(47, 109, 246, 0.18);
  }
  74%, 100% {
    background-color: rgba(47, 109, 246, 0);
  }
}
@media (max-width: 340px) {
  .cm {
    padding-bottom: 68px;
  }
  .cm__menu {
    min-width: 120px;
  }
  .cm__dots {
    width: 26px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .cm.is-demo .cm__dots,
  .cm.is-demo .cm__menu,
  .cm.is-demo .cm__menu a {
    animation: none !important;
  }
  .cm.is-demo .cm__menu {
    opacity: 1;
    transform: none;
  }
  .cm__dots, .cm__menu {
    transition: none;
  }
}

// 실동작: 클릭 토글 · Escape 로 닫기 · ArrowDown/ArrowUp 으로 항목 이동 · 목록 밖 클릭으로 닫기
var root = document.querySelector('.cm');
var slot = document.getElementById('cm-slot');
var btn = document.getElementById('cm-btn');
var links = [].slice.call(document.querySelectorAll('#cm-menu a'));
function isOpen() { return btn.getAttribute('aria-expanded') === 'true'; }
function setOpen(on, restoreFocus) {
  root.classList.remove('is-demo');
  slot.classList.toggle('is-open', on);
  btn.setAttribute('aria-expanded', on ? 'true' : 'false');
  if (on) links[0].focus({ preventScroll: true });
  else if (restoreFocus) btn.focus({ preventScroll: true });
}
btn.addEventListener('click', function (e) { e.stopPropagation(); setOpen(!isOpen(), true); });
document.addEventListener('keydown', function (e) {
  if (e.key === 'Escape' && isOpen()) { e.preventDefault(); setOpen(false, true); return; }
  if (e.key !== 'ArrowDown' && e.key !== 'ArrowUp') return;
  var i = links.indexOf(document.activeElement);
  if (i < 0 && document.activeElement !== btn) return;
  e.preventDefault();
  if (!isOpen()) { setOpen(true, false); return; }
  var step = e.key === 'ArrowDown' ? 1 : links.length - 1;
  links[(i + step + links.length) % links.length].focus({ preventScroll: true });
});
document.addEventListener('click', function (e) {
  if (isOpen() && !slot.contains(e.target)) setOpen(false, false);
});

import { useEffect, useRef, useState } from "react";
import type { CSSProperties } from "react";
import styles from "./CollapseMiddleMenu.module.scss";

export type CollapseMiddleMenuProps = {
  head?: string;
  hidden?: string[];
  tail?: string[];
  duration?: number;
  easing?: string;
  color?: string;
};

type KeyEvt = { key: string; preventDefault(): void };
type Vars = CSSProperties & { "--duration"?: string; "--easing"?: string; "--color"?: string };

const IconDots = () => (
  <svg viewBox="0 0 256 256" width="16" height="16" aria-hidden="true"><g fill="currentColor"><path d="M240 96v64a16 16 0 0 1-16 16H32a16 16 0 0 1-16-16V96a16 16 0 0 1 16-16h192a16 16 0 0 1 16 16" opacity=".2"/><path d="M140 128a12 12 0 1 1-12-12a12 12 0 0 1 12 12m56-12a12 12 0 1 0 12 12a12 12 0 0 0-12-12m-136 0a12 12 0 1 0 12 12a12 12 0 0 0-12-12"/></g></svg>
);
const IconFolder = () => (
  <svg viewBox="0 0 256 256" width="14" height="14" aria-hidden="true"><g fill="currentColor"><path d="M128 80H32V56a8 8 0 0 1 8-8h52.69a8 8 0 0 1 5.65 2.34Z" opacity=".2"/><path d="M216 72h-84.69L104 44.69A15.86 15.86 0 0 0 92.69 40H40a16 16 0 0 0-16 16v144.62A15.4 15.4 0 0 0 39.38 216h177.51A15.13 15.13 0 0 0 232 200.89V88a16 16 0 0 0-16-16M92.69 56l16 16H40V56ZM216 200H40V88h176Z"/></g></svg>
);

export default function CollapseMiddleMenu({
  head = "Home",
  hidden = ["Electronics", "Computers"],
  tail = ["Laptops", "13-inch gaming"],
  duration = 220,
  easing = "cubic-bezier(.2,.8,.2,1)",
  color = "#2f6df6",
}: CollapseMiddleMenuProps) {
  const [open, setOpen] = useState(false);
  const slotRef = useRef<HTMLLIElement>(null);
  const btnRef = useRef<HTMLButtonElement>(null);
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  useEffect(() => {
    if (!open) return;
    const onDoc = (e: Event) => {
      const el = slotRef.current;
      if (el && e.target && !el.contains(e.target as Node)) setOpen(false);
    };
    document.addEventListener("click", onDoc);
    return () => document.removeEventListener("click", onDoc);
  }, [open]);

  function step(dir: number) {
    const el = slotRef.current;
    if (!el) return;
    const links = Array.from(el.querySelectorAll("a"));
    const i = links.indexOf(document.activeElement as HTMLAnchorElement);
    links[(i + dir + links.length) % links.length].focus({ preventScroll: true });
  }

  function onKey(e: KeyEvt) {
    if (e.key === "Escape" && open) {
      e.preventDefault();
      setOpen(false);
      btnRef.current?.focus({ preventScroll: true });
      return;
    }
    if (e.key !== "ArrowDown" && e.key !== "ArrowUp") return;
    e.preventDefault();
    if (!open) setOpen(true);
    else step(e.key === "ArrowDown" ? 1 : -1);
  }

  return (
    <div className={styles.cm} style={vars} onKeyDown={onKey}>
      <nav aria-label="Breadcrumb">
        <ol className={styles.list}>
          <li><a href="#">{head}</a></li>
          <li ref={slotRef} className={[styles.slot, open ? styles.isOpen : ""].join(" ")}>
            <button
              ref={btnRef}
              type="button"
              className={styles.dots}
              aria-expanded={open}
              aria-controls="cm-menu"
              aria-label="Show hidden steps"
              onClick={(): void => setOpen(!open)}
            >
              <IconDots />
            </button>
            <ul className={styles.menu} id="cm-menu">
              {hidden.map((label) => (
                <li key={label}><a href="#"><IconFolder />{label}</a></li>
              ))}
            </ul>
          </li>
          {tail.map((label, i) => (
            <li key={label}>
              {i === tail.length - 1
                ? <span className={styles.cur} aria-current="page">{label}</span>
                : <a href="#">{label}</a>}
            </li>
          ))}
        </ol>
      </nav>
    </div>
  );
}