08Nested menu

<main class="stage is-demo">
  <div class="page" id="page8">
    <button class="trigger" type="button" aria-haspopup="dialog" aria-controls="drawer8">Open menu</button>
  </div>
  <div class="overlay"></div>
  <nav class="drawer" id="drawer8" role="dialog" aria-modal="true" aria-labelledby="t8">
    <h2 id="t8">Categories</h2>
    <a class="drawer__link" href="#">All</a>
    <div class="group">
      <button class="group__toggle" type="button" aria-expanded="false" aria-controls="sub8">
        Women <span class="chevron" aria-hidden="true"></span>
      </button>
      <div class="submenu" id="sub8">
        <div class="submenu__inner">
          <a href="#">Tops</a>
          <a href="#">Bottoms</a>
          <a href="#">Shoes</a>
        </div>
      </div>
    </div>
    <a class="drawer__link" href="#">Brands</a>
    <button class="drawer__close" type="button">Close</button>
  </nav>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-enter;      // 600ms — 드로어가 밀려 들어오는 시간
$easing: $ease-spring;
$color: $subject-blue;      // 하위 메뉴 강조색

// ── 데모 무대 ───────────────────────────────────────────
@include stage($stage-paper);

.stage { position: relative; }
.page { display: grid; place-items: center; }

.trigger {
  border: 0; border-radius: $r-pill;
  padding: $sp-3 $sp-6;
  font-weight: 600;
  font-size: clamp(13px, 4vmin, 16px);
  line-height: 1;
  font-family: inherit;
  color: $stage-paper; background: $color;
  cursor: pointer; -webkit-tap-highlight-color: transparent;
}

.overlay {
  position: fixed; inset: 0;
  background: rgba($stage-ink, .5);
  opacity: 0; pointer-events: none;
  transition: opacity $duration $easing;
}

.drawer {
  position: fixed; left: 0; top: 0; bottom: 0; right: auto;
  transform: translateX(-100%);
  width: min(76vw, 240px);
  box-sizing: border-box;
  display: flex; flex-direction: column; gap: $sp-1;
  padding: $sp-6 $sp-4;
  background: $stage-ink; color: $stage-paper;
  box-shadow: $shadow-raised;
  pointer-events: none;
  transition: transform $duration $easing;

  h2 { margin: 0 0 $sp-2; font-size: clamp(13px, 4.2vmin, 17px); }
}

.drawer__link, .group__toggle {
  padding: $sp-2 $sp-1;
  border-radius: $r-sm;
  color: $stage-paper; text-decoration: none; font-weight: 500; font-size: 13px; line-height: 1; font-family: inherit;
  &:hover, &:focus-visible { background: rgba($stage-paper, .1); }
}

.group__toggle {
  border: 0; background: transparent;
  display: flex; align-items: center; justify-content: space-between;
  width: 100%; cursor: pointer;
  font-family: inherit;
}

// 체크와 같은 원리: 한 요소의 border 코너를 45° 돌려 화살표를 만든다(BD16)
.chevron {
  width: $sp-2; height: $sp-2;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg);
  transition: transform $dur-base $ease-out;
}
.group.is-open .chevron { transform: rotate(225deg); }

// height:auto 트랜지션 — grid-template-rows 0fr → 1fr (017-01 과 같은 방식)
.submenu {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows $dur-base $ease-out;
}
.submenu__inner {
  overflow: hidden;
  display: flex; flex-direction: column; gap: $sp-1;
  padding-left: $sp-4;

  a { color: $stage-paper; opacity: .8; text-decoration: none; font-weight: 400; font-size: 12px; line-height: 1.8; font-family: inherit; }
  a:hover, a:focus-visible { opacity: 1; color: $color; }
}
.group.is-open .submenu { grid-template-rows: 1fr; }

.drawer__close {
  margin-top: auto;
  border: 0; border-radius: $r-control;
  background: $color; color: $stage-paper;
  padding: $sp-2 $sp-4;
  font-weight: 600; font-size: 13px; line-height: 1; font-family: inherit; cursor: pointer;
}

.stage.is-open .overlay { opacity: 1; pointer-events: auto; }
.stage.is-open .drawer  { transform: translateX(0); pointer-events: auto; }

// 데모 루프: 드로어가 들어온 뒤 하위 메뉴가 펼쳐졌다 접히고, 드로어가 다시 나간다
.stage.is-demo .overlay  { animation: overlay-loop $dur-loop ease-in-out infinite; }
.stage.is-demo .drawer   { animation: drawer-loop $dur-loop $easing infinite; }
.stage.is-demo .submenu  { animation: submenu-loop $dur-loop $ease-out infinite; }
.stage.is-demo .chevron  { animation: chevron-loop $dur-loop $ease-out infinite; }

@keyframes overlay-loop {
  0%, 100% { opacity: 0; }
  12%, 90% { opacity: 1; }
  96%      { opacity: 0; }
}
@keyframes drawer-loop {
  0%, 100%  { transform: translateX(-100%); }
  12%, 90%  { transform: translateX(0); }
  96%       { transform: translateX(-100%); }
}
@keyframes submenu-loop {
  0%, 25%, 100% { grid-template-rows: 0fr; }
  45%, 75%      { grid-template-rows: 1fr; }
}
@keyframes chevron-loop {
  0%, 25%, 100% { transform: rotate(45deg); }
  45%, 75%      { transform: rotate(225deg); }
}

@media (prefers-reduced-motion: reduce) {
  .stage.is-demo .overlay, .stage.is-demo .drawer, .stage.is-demo .submenu, .stage.is-demo .chevron { animation: none; }
  .overlay, .drawer, .submenu, .chevron { transition-duration: 1ms; }
}

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);
}

.stage {
  position: relative;
}

.page {
  display: grid;
  place-items: center;
}

.trigger {
  border: 0;
  border-radius: 999px;
  padding: 12px 24px;
  font-weight: 600;
  font-size: clamp(13px, 4vmin, 16px);
  line-height: 1;
  font-family: inherit;
  color: #ffffff;
  background: #2f6df6;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(23, 20, 26, 0.5);
  opacity: 0;
  pointer-events: none;
  transition: opacity 600ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.drawer {
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  right: auto;
  transform: translateX(-100%);
  width: min(76vw, 240px);
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 24px 16px;
  background: #17141a;
  color: #ffffff;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  pointer-events: none;
  transition: transform 600ms cubic-bezier(0.2, 0.8, 0.2, 1);
}
.drawer h2 {
  margin: 0 0 8px;
  font-size: clamp(13px, 4.2vmin, 17px);
}

.drawer__link, .group__toggle {
  padding: 8px 4px;
  border-radius: 8px;
  color: #ffffff;
  text-decoration: none;
  font-weight: 500;
  font-size: 13px;
  line-height: 1;
  font-family: inherit;
}
.drawer__link:hover, .drawer__link:focus-visible, .group__toggle:hover, .group__toggle:focus-visible {
  background: rgba(255, 255, 255, 0.1);
}

.group__toggle {
  border: 0;
  background: transparent;
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  cursor: pointer;
  font-family: inherit;
}

.chevron {
  width: 8px;
  height: 8px;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg);
  transition: transform 300ms ease-out;
}

.group.is-open .chevron {
  transform: rotate(225deg);
}

.submenu {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 300ms ease-out;
}

.submenu__inner {
  overflow: hidden;
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-left: 16px;
}
.submenu__inner a {
  color: #ffffff;
  opacity: 0.8;
  text-decoration: none;
  font-weight: 400;
  font-size: 12px;
  line-height: 1.8;
  font-family: inherit;
}
.submenu__inner a:hover, .submenu__inner a:focus-visible {
  opacity: 1;
  color: #2f6df6;
}

.group.is-open .submenu {
  grid-template-rows: 1fr;
}

.drawer__close {
  margin-top: auto;
  border: 0;
  border-radius: 12px;
  background: #2f6df6;
  color: #ffffff;
  padding: 8px 16px;
  font-weight: 600;
  font-size: 13px;
  line-height: 1;
  font-family: inherit;
  cursor: pointer;
}

.stage.is-open .overlay {
  opacity: 1;
  pointer-events: auto;
}

.stage.is-open .drawer {
  transform: translateX(0);
  pointer-events: auto;
}

.stage.is-demo .overlay {
  animation: overlay-loop 2s ease-in-out infinite;
}

.stage.is-demo .drawer {
  animation: drawer-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.stage.is-demo .submenu {
  animation: submenu-loop 2s ease-out infinite;
}

.stage.is-demo .chevron {
  animation: chevron-loop 2s ease-out infinite;
}

@keyframes overlay-loop {
  0%, 100% {
    opacity: 0;
  }
  12%, 90% {
    opacity: 1;
  }
  96% {
    opacity: 0;
  }
}
@keyframes drawer-loop {
  0%, 100% {
    transform: translateX(-100%);
  }
  12%, 90% {
    transform: translateX(0);
  }
  96% {
    transform: translateX(-100%);
  }
}
@keyframes submenu-loop {
  0%, 25%, 100% {
    grid-template-rows: 0fr;
  }
  45%, 75% {
    grid-template-rows: 1fr;
  }
}
@keyframes chevron-loop {
  0%, 25%, 100% {
    transform: rotate(45deg);
  }
  45%, 75% {
    transform: rotate(225deg);
  }
}
@media (prefers-reduced-motion: reduce) {
  .stage.is-demo .overlay, .stage.is-demo .drawer, .stage.is-demo .submenu, .stage.is-demo .chevron {
    animation: none;
  }
  .overlay, .drawer, .submenu, .chevron {
    transition-duration: 1ms;
  }
}

(function () {
  var stage = document.querySelector('.stage');
  var page = document.getElementById('page8');
  var trigger = document.querySelector('.trigger');
  var overlay = document.querySelector('.overlay');
  var drawer = document.querySelector('.drawer');
  var closeBtn = document.querySelector('.drawer__close');
  var group = document.querySelector('.group');
  var groupToggle = document.querySelector('.group__toggle');
  function focusables() { return drawer.querySelectorAll('a, button'); }
  function open() {
    stage.classList.remove('is-demo'); stage.classList.add('is-open');
    page.setAttribute('inert', ''); page.setAttribute('aria-hidden', 'true');
    focusables()[0].focus({ preventScroll: true });
  }
  function shut() {
    stage.classList.remove('is-open');
    page.removeAttribute('inert'); page.removeAttribute('aria-hidden');
    trigger.focus({ preventScroll: true });
  }
  trigger.addEventListener('click', open);
  overlay.addEventListener('click', shut);
  closeBtn.addEventListener('click', shut);
  groupToggle.addEventListener('click', function () {
    var open = group.classList.toggle('is-open');
    groupToggle.setAttribute('aria-expanded', String(open));
  });
  document.addEventListener('keydown', function (e) {
    if (!stage.classList.contains('is-open')) return;
    if (e.key === 'Escape') { shut(); return; }
    if (e.key !== 'Tab') return;
    var f = focusables(), first = f[0], last = f[f.length - 1];
    if (e.shiftKey && document.activeElement === first) { last.focus({ preventScroll: true }); e.preventDefault(); }
    else if (!e.shiftKey && document.activeElement === last) { first.focus({ preventScroll: true }); e.preventDefault(); }
  });
})();

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

export type NestedMenuDrawerProps = {
  duration?: number;
  easing?: string;
  color?: string;
};

export default function NestedMenuDrawer({
  duration = 600,
  easing = "cubic-bezier(.2,.8,.2,1)",
  color = "#2f6df6",
}: NestedMenuDrawerProps) {
  const [open, setOpen] = useState(false);
  const [groupOpen, setGroupOpen] = useState(false);
  const drawerRef = useRef<HTMLElement | null>(null);
  const triggerRef = useRef<HTMLButtonElement | null>(null);

  useEffect(() => {
    if (!open) { triggerRef.current?.focus(); return; }
    const drawer = drawerRef.current;
    if (!drawer) return;
    const focusables = () => Array.from(drawer.querySelectorAll<HTMLElement>("a, button"));
    focusables()[0]?.focus();
    function onKey(e: KeyboardEvent) {
      if (e.key === "Escape") { setOpen(false); return; }
      if (e.key !== "Tab") return;
      const f = focusables();
      const first = f[0], last = f[f.length - 1];
      if (e.shiftKey && document.activeElement === first) { last.focus(); e.preventDefault(); }
      else if (!e.shiftKey && document.activeElement === last) { first.focus(); e.preventDefault(); }
    }
    document.addEventListener("keydown", onKey);
    return () => document.removeEventListener("keydown", onKey);
  }, [open]);

  const vars: CSSProperties = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  return (
    <div className={styles.stage} style={vars}>
      <div className={styles.page} inert={open || undefined} aria-hidden={open}>
        <button ref={triggerRef} className={styles.trigger} type="button" onClick={() => setOpen(true)}>
          메뉴 열기
        </button>
      </div>
      <div className={styles.overlay} data-open={open} onClick={() => setOpen(false)} />
      <nav ref={drawerRef} className={styles.drawer} data-open={open} role="dialog" aria-modal="true" aria-label="카테고리">
        <h2>카테고리</h2>
        <a className={styles.link} href="#">전체</a>
        <div className={styles.group}>
          <button
            className={styles.groupToggle}
            type="button"
            aria-expanded={groupOpen}
            onClick={() => setGroupOpen((v) => !v)}
          >
            여성 <span className={styles.chevron} data-open={groupOpen} aria-hidden="true" />
          </button>
          <div className={styles.submenu} data-open={groupOpen}>
            <div className={styles.submenuInner}>
              <a href="#">상의</a>
              <a href="#">하의</a>
              <a href="#">신발</a>
            </div>
          </div>
        </div>
        <a className={styles.link} href="#">브랜드</a>
        <button className={styles.close} type="button" onClick={() => setOpen(false)}>닫기</button>
      </nav>
    </div>
  );
}