03가운데가 앞으로 나오는 깊이 슬라이더

<main class="stage">
<section class="cf is-demo" id="cf" tabindex="0" role="region" aria-roledescription="carousel" aria-label="앨범 표지 깊이 슬라이더">
  <div class="cf__box">
    <div class="cf__track" id="track">
      <button class="cf__card" type="button" aria-roledescription="slide">
        <span class="cf__art cf__art--a" role="img" aria-label="물안개가 낮게 덮인 잔잔한 호수 표지"></span>
        <span class="cf__name">새벽 호수</span>
      </button>
      <button class="cf__card" type="button" aria-roledescription="slide">
        <span class="cf__art cf__art--b" role="img" aria-label="해 질 무렵 붉게 물든 사막 바위 표지"></span>
        <span class="cf__name">붉은 사막</span>
      </button>
      <button class="cf__card" type="button" aria-roledescription="slide">
        <span class="cf__art cf__art--c" role="img" aria-label="불 켜진 승강장이 늘어선 밤 기차 정거장 표지"></span>
        <span class="cf__name">밤의 정거장</span>
      </button>
      <button class="cf__card" type="button" aria-roledescription="slide">
        <span class="cf__art cf__art--d" role="img" aria-label="비가 갠 뒤 젖은 초록 언덕과 낮은 구름 표지"></span>
        <span class="cf__name">초록 언덕</span>
      </button>
      <button class="cf__card" type="button" aria-roledescription="slide">
        <span class="cf__art cf__art--e" role="img" aria-label="푸른 얼음 조각이 떠 있는 겨울 바다 표지"></span>
        <span class="cf__name">얼음 바다</span>
      </button>
    </div>
  </div>
  <div class="cf__bar">
    <button class="cf__nav" id="prev" type="button" aria-label="이전 표지"><svg xmlns="http://www.w3.org/2000/svg" width="1em" height="1em" viewBox="0 0 256 256" aria-hidden="true"><g fill="currentColor"><path d="M160 48v160l-80-80Z" opacity=".2"/><path d="M163.06 40.61a8 8 0 0 0-8.72 1.73l-80 80a8 8 0 0 0 0 11.32l80 80A8 8 0 0 0 168 208V48a8 8 0 0 0-4.94-7.39M152 188.69L91.31 128L152 67.31Z"/></g></svg></button>
    <div class="cf__dots" id="dots"></div>
    <button class="cf__nav" id="next" type="button" aria-label="다음 표지"><svg xmlns="http://www.w3.org/2000/svg" width="1em" height="1em" viewBox="0 0 256 256" aria-hidden="true"><g fill="currentColor"><path d="m176 128l-80 80V48Z" opacity=".2"/><path d="m181.66 122.34l-80-80A8 8 0 0 0 88 48v160a8 8 0 0 0 13.66 5.66l80-80a8 8 0 0 0 0-11.32M104 188.69V67.31L164.69 128Z"/></g></svg></button>
  </div>
</section>
</main>

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

// 가운데가 앞으로 나오는 깊이 슬라이더.
// 무대(.cf__box)가 perspective 를 걸고 트랙(.cf__track)이 transform-style: preserve-3d 로 3D 공간을 연다.
// JS 는 카드마다 "활성 장에서 몇 칸 떨어졌는가"(--d) 와 그 절댓값(--ad) 만 얹는다 —
// 옆으로 밀리는 거리·rotateY 각도·뒤로 물러나는 깊이·축소·흐림은 전부 이 두 숫자의 calc() 다.
// 스크롤 위치를 읽지 않는다(scroll-snap 아님). 그래서 화살표·점·카드 클릭이 전부 같은 인덱스를 만진다.
// 표지 자리는 FLUX 키가 오면 배경만 갈아 끼운다 (run/082/_이미지후보.01.json).

$duration: $dur-enter;
$easing: $ease-out;
$color: $subject-blue;

$panel: $subject-blue-deep;          // 크림 글자를 얹는 파란 면 — 5.98:1
$veil: rgba($subject-ink, .72);      // 주황 무대 위 조작 면
$card-w: clamp(80px, 24vw, 112px);
$step: clamp(48px, 15vw, 72px);      // 한 칸 옆으로 밀리는 거리
$name-fs: clamp(9px, 2.4vw, 11px);

@include stage($stage-orange);

.cf {
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: $sp-2;
  width: min(100%, 420px);
}
.cf:focus-visible { outline: 3px solid $subject-ink; outline-offset: 3px; }

// ── 깊이가 생기는 무대. 여기 perspective 가 없으면 rotateY 는 납작한 가로 눌림으로만 보인다
.cf__box {
  position: relative;
  width: 100%;
  height: clamp(96px, 46vh, 140px);
  perspective: 900px;
  perspective-origin: 50% 50%;
  overflow: hidden;
}
.cf__track {
  position: absolute;
  inset: 0;
  transform-style: preserve-3d;
}

// ── 카드 하나. 두 숫자(--d · --ad)만 받아 스스로 자리를 잡는다
.cf__card {
  position: absolute;
  left: 50%;
  top: 50%;
  width: $card-w;
  height: $card-w;
  padding: 0;
  border: 0;
  border-radius: $r-card;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  background: $subject-ink;
  cursor: pointer;
  backface-visibility: hidden;
  box-shadow: 0 0 0 2px rgba($subject-cream, .30), $shadow-raised;
  // 깊이는 translateZ 가 아니라 rotateY + 축소로 만든다. perspective 를 건 3D 공간 안에서
  // translateZ 로 물러난 요소는 Chrome 이 **적중 판정(hit test)에서 빼 버린다** — 화면에는 보이는데
  // 클릭이 트랙으로 빠진다 (2026-09-14 실측: elementFromPoint 가 옆 카드 자리에서 .cf__track 을 돌려줬다).
  // z 를 0 으로 두면 같은 자리에서 다섯 장이 전부 눌린다.
  transform:
    translate3d(calc(-50% + var(--d, 0) * #{$step}), -50%, 0)
    rotateY(calc(var(--d, 0) * -34deg))
    scale(calc(1 - .12 * var(--ad, 0)));
  // 두 칸까지는 불투명하게 두고 세 칸째부터 사라진다 — 반투명 카드는 주황 무대가 비쳐 탁해진다 (실측 2026-09-14)
  opacity: calc(3 - var(--ad, 0));
  transition: transform $duration $easing, opacity $duration $easing;
}
// 멀어질수록 어두워지는 것은 투명도가 아니라 카드 위에 덮는 먹 장막이다
.cf__card::after {
  content: "";
  position: absolute;
  inset: 0;
  background: $subject-ink;
  opacity: calc(.26 * var(--ad, 0));
  pointer-events: none;
  transition: opacity $duration $easing;
}
.cf__card[aria-current="true"] { box-shadow: 0 0 0 3px $color, $shadow-raised; }
.cf__card:focus-visible { outline: 3px solid $subject-ink; outline-offset: 3px; }

// ── 표지 그림 자리
.cf__art { position: absolute; inset: 0; background-repeat: no-repeat; background-size: cover; }

.cf__art--a {
  background-image:
    radial-gradient(circle at 36% 30%, rgba($subject-cream, .84), rgba($subject-cream, 0) 30%),
    linear-gradient(180deg, rgba($subject-cream, 0) 60%, rgba($subject-cream, .34) 60.4%, rgba($subject-cream, 0) 70%),
    linear-gradient(176deg, mix($subject-sky, $subject-cream, 46%) 0%, mix($subject-blue, $subject-ink, 48%) 62%, mix($subject-ink, $subject-blue, 78%) 100%);
}
.cf__art--b {
  background-image:
    radial-gradient(circle at 68% 26%, rgba($subject-cream, .88), rgba($subject-cream, 0) 16%),
    linear-gradient(104deg, rgba($subject-ink, 0) 54%, mix($subject-ink, $stage-orange, 70%) 54.6%),
    linear-gradient(182deg, mix($stage-orange, $subject-cream, 38%) 0%, $stage-orange 46%, mix($stage-orange, $subject-ink, 54%) 100%);
}
.cf__art--c {
  background-image:
    linear-gradient(90deg, rgba($stage-yellow, 0) 22%, rgba($stage-yellow, .58) 22.6%, rgba($stage-yellow, 0) 26%,
      rgba($stage-yellow, 0) 48%, rgba($stage-yellow, .46) 48.6%, rgba($stage-yellow, 0) 52%,
      rgba($stage-yellow, 0) 74%, rgba($stage-yellow, .52) 74.6%, rgba($stage-yellow, 0) 78%),
    linear-gradient(180deg, rgba($subject-ink, 0) 64%, mix($subject-ink, $stage-yellow, 82%) 64.6%),
    linear-gradient(178deg, mix($subject-blue, $subject-ink, 24%) 0%, $subject-ink 84%);
}
.cf__art--d {
  background-image:
    radial-gradient(circle at 26% 22%, rgba($stage-paper, .72), rgba($stage-paper, 0) 28%),
    linear-gradient(86deg, rgba($subject-mint, 0) 44%, mix($subject-mint, $subject-ink, 58%) 44.6%),
    linear-gradient(174deg, mix($subject-sky, $subject-cream, 52%) 0%, mix($subject-mint, $stage-paper, 64%) 48%, mix($subject-mint, $subject-ink, 46%) 100%);
}
.cf__art--e {
  background-image:
    linear-gradient(118deg, rgba($stage-paper, 0) 34%, rgba($stage-paper, .82) 34.6%, rgba($stage-paper, .82) 44%, rgba($stage-paper, 0) 44.6%),
    linear-gradient(62deg, rgba($stage-paper, 0) 66%, rgba($stage-paper, .62) 66.6%, rgba($stage-paper, 0) 74%),
    linear-gradient(180deg, mix($subject-sky, $stage-paper, 46%) 0%, mix($subject-sky, $subject-blue, 52%) 54%, mix($subject-blue, $subject-ink, 60%) 100%);
}

// ── 표지 제목 띠. 파란 면 위 크림 글자 (5.98:1)
.cf__name {
  position: relative;
  padding: $sp-1 $sp-2;
  background: $panel;
  color: $subject-cream;
  font-weight: 700;
  font-size: $name-fs;
  line-height: 1.4;
  text-align: left;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

// ── 조작 줄
.cf__bar { display: flex; align-items: center; gap: $sp-2; }
.cf__nav {
  width: 28px;
  height: 28px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: $veil;
  color: $subject-cream;
  font-size: 17px;
  cursor: pointer;
  transition: transform $dur-quick $easing;
}
.cf__nav:hover { transform: scale(1.12); }
.cf__nav:focus-visible { outline: 3px solid $subject-ink; outline-offset: 2px; }

.cf__dots {
  display: flex;
  align-items: center;
  gap: $sp-2;
  padding: $sp-1 $sp-2;
  border-radius: $r-pill;
  background: $veil;
}
.cf__dot {
  width: 8px;
  height: 8px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: rgba($subject-cream, .52);
  cursor: pointer;
  transition: transform $dur-quick $easing, background-color $dur-quick $easing;
}
.cf__dot[aria-current="true"] { background: $color; transform: scale(1.5); }
.cf__dot:focus-visible { outline: 2px solid $subject-cream; outline-offset: 2px; }

// ── 좁은 화면: 조작 줄을 한 단계 줄인다
@media (max-width: 360px) {
  .cf { gap: $sp-1; }
  .cf__nav { width: 24px; height: 24px; font-size: 15px; }
  .cf__dots { gap: $sp-1; }
}

@media (prefers-reduced-motion: reduce) {
  .cf__card,
  .cf__card::after,
  .cf__nav,
  .cf__dot { transition-duration: 0s; }
}

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);
}

.cf {
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  width: min(100%, 420px);
}

.cf:focus-visible {
  outline: 3px solid #17141a;
  outline-offset: 3px;
}

.cf__box {
  position: relative;
  width: 100%;
  height: clamp(96px, 46vh, 140px);
  perspective: 900px;
  perspective-origin: 50% 50%;
  overflow: hidden;
}

.cf__track {
  position: absolute;
  inset: 0;
  transform-style: preserve-3d;
}

.cf__card {
  position: absolute;
  left: 50%;
  top: 50%;
  width: clamp(80px, 24vw, 112px);
  height: clamp(80px, 24vw, 112px);
  padding: 0;
  border: 0;
  border-radius: 16px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  background: #17141a;
  cursor: pointer;
  backface-visibility: hidden;
  box-shadow: 0 0 0 2px rgba(255, 247, 230, 0.3), 0 14px 24px rgba(23, 20, 26, 0.32);
  transform: translate3d(calc(-50% + var(--d, 0) * clamp(48px, 15vw, 72px)), -50%, 0) rotateY(calc(var(--d, 0) * -34deg)) scale(calc(1 - 0.12 * var(--ad, 0)));
  opacity: calc(3 - var(--ad, 0));
  transition: transform 600ms ease-out, opacity 600ms ease-out;
}

.cf__card::after {
  content: "";
  position: absolute;
  inset: 0;
  background: #17141a;
  opacity: calc(0.26 * var(--ad, 0));
  pointer-events: none;
  transition: opacity 600ms ease-out;
}

.cf__card[aria-current=true] {
  box-shadow: 0 0 0 3px #2f6df6, 0 14px 24px rgba(23, 20, 26, 0.32);
}

.cf__card:focus-visible {
  outline: 3px solid #17141a;
  outline-offset: 3px;
}

.cf__art {
  position: absolute;
  inset: 0;
  background-repeat: no-repeat;
  background-size: cover;
}

.cf__art--a {
  background-image: radial-gradient(circle at 36% 30%, rgba(255, 247, 230, 0.84), rgba(255, 247, 230, 0) 30%), linear-gradient(180deg, rgba(255, 247, 230, 0) 60%, rgba(255, 247, 230, 0.34) 60.4%, rgba(255, 247, 230, 0) 70%), linear-gradient(176deg, rgb(73.8431372549%, 88.3843137255%, 94.7058823529%) 0%, rgb(13.537254902%, 24.5960784314%, 51.6078431373%) 62%, rgb(11.0901960784%, 15.5215686275%, 29.1764705882%) 100%);
}

.cf__art--b {
  background-image: radial-gradient(circle at 68% 26%, rgba(255, 247, 230, 0.88), rgba(255, 247, 230, 0) 16%), linear-gradient(104deg, rgba(23, 20, 26, 0) 54%, rgb(36.3137254902%, 14.5490196078%, 10.7843137255%) 54.6%), linear-gradient(182deg, rgb(100%, 71.5294117647%, 60.5411764706%) 0%, #ff4d1f 46%, rgb(58.1490196078%, 19.9137254902%, 11.2549019608%) 100%);
}

.cf__art--c {
  background-image: linear-gradient(90deg, rgba(255, 210, 63, 0) 22%, rgba(255, 210, 63, 0.58) 22.6%, rgba(255, 210, 63, 0) 26%, rgba(255, 210, 63, 0) 48%, rgba(255, 210, 63, 0.46) 48.6%, rgba(255, 210, 63, 0) 52%, rgba(255, 210, 63, 0) 74%, rgba(255, 210, 63, 0.52) 74.6%, rgba(255, 210, 63, 0) 78%), linear-gradient(180deg, rgba(23, 20, 26, 0) 64%, rgb(25.3960784314%, 21.2549019608%, 12.8078431373%) 64.6%), linear-gradient(178deg, rgb(11.2784313725%, 16.2196078431%, 30.9019607843%) 0%, #17141a 84%);
}

.cf__art--d {
  background-image: radial-gradient(circle at 26% 22%, rgba(255, 255, 255, 0.72), rgba(255, 255, 255, 0) 28%), linear-gradient(86deg, rgba(76, 212, 166, 0) 44%, rgb(21.0745098039%, 51.5137254902%, 42.0392156863%) 44.6%), linear-gradient(174deg, rgb(70.431372549%, 87.2784313725%, 95.2941176471%) 0%, rgb(55.0745098039%, 89.2078431373%, 77.662745098%) 48%, rgb(18.5803921569%, 42.4784313725%, 35.4509803922%) 100%);
}

.cf__art--e {
  background-image: linear-gradient(118deg, rgba(255, 255, 255, 0) 34%, rgba(255, 255, 255, 0.82) 34.6%, rgba(255, 255, 255, 0.82) 44%, rgba(255, 255, 255, 0) 44.6%), linear-gradient(62deg, rgba(255, 255, 255, 0) 66%, rgba(255, 255, 255, 0.62) 66.6%, rgba(255, 255, 255, 0) 74%), linear-gradient(180deg, rgb(73.8431372549%, 90.0784313725%, 100%) 0%, rgb(31.2784313725%, 61.3019607843%, 98.3058823529%) 54%, rgb(14.6666666667%, 28.7843137255%, 61.9607843137%) 100%);
}

.cf__name {
  position: relative;
  padding: 4px 8px;
  background: #0a4fe8;
  color: #fff7e6;
  font-weight: 700;
  font-size: clamp(9px, 2.4vw, 11px);
  line-height: 1.4;
  text-align: left;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.cf__bar {
  display: flex;
  align-items: center;
  gap: 8px;
}

.cf__nav {
  width: 28px;
  height: 28px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: rgba(23, 20, 26, 0.72);
  color: #fff7e6;
  font-size: 17px;
  cursor: pointer;
  transition: transform 220ms ease-out;
}

.cf__nav:hover {
  transform: scale(1.12);
}

.cf__nav:focus-visible {
  outline: 3px solid #17141a;
  outline-offset: 2px;
}

.cf__dots {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 4px 8px;
  border-radius: 999px;
  background: rgba(23, 20, 26, 0.72);
}

.cf__dot {
  width: 8px;
  height: 8px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: rgba(255, 247, 230, 0.52);
  cursor: pointer;
  transition: transform 220ms ease-out, background-color 220ms ease-out;
}

.cf__dot[aria-current=true] {
  background: #2f6df6;
  transform: scale(1.5);
}

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

@media (max-width: 360px) {
  .cf {
    gap: 4px;
  }
  .cf__nav {
    width: 24px;
    height: 24px;
    font-size: 15px;
  }
  .cf__dots {
    gap: 4px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .cf__card,
  .cf__card::after,
  .cf__nav,
  .cf__dot {
    transition-duration: 0s;
  }
}

// 스크롤 위치가 아니라 "활성 장에서 몇 칸 떨어졌는가" 가 모양을 정한다.
// JS 는 카드마다 거리 d 와 |d| 만 CSS 변수로 얹고, rotateY·translateZ·축소는 CSS 가 계산한다.
var cf = document.getElementById('cf');
var track = document.getElementById('track');
var dotsBox = document.getElementById('dots');
var cards = track.querySelectorAll('.cf__card');
var SLIDE_LABEL = '{total}장 중 {n}장 · {name}';
var DOT_LABEL = '{n}번째 표지 보기';
var total = cards.length;
var index = 0;
var timer = 0;
var dots = [];
function picker(n) { return function () { stop(); go(n); }; }
function go(n) {
  index = (n + total) % total;
  for (var k = 0; k < total; k++) {
    var d = k - index;
    var far = Math.abs(d);
    cards[k].style.setProperty('--d', d);
    cards[k].style.setProperty('--ad', far);
    cards[k].style.zIndex = String(total - far);
    cards[k].style.pointerEvents = far > 2 ? 'none' : 'auto';
    cards[k].setAttribute('aria-current', d === 0 ? 'true' : 'false');
    dots[k].setAttribute('aria-current', d === 0 ? 'true' : 'false');
  }
}
function stop() {
  cf.classList.remove('is-demo');
  if (timer) { clearInterval(timer); timer = 0; }
}
for (var i = 0; i < total; i++) {
  var name = cards[i].querySelector('.cf__name').textContent;
  cards[i].setAttribute('aria-label', SLIDE_LABEL.replace('{n}', i + 1).replace('{total}', total).replace('{name}', name));
  cards[i].addEventListener('click', picker(i));
  var dot = document.createElement('button');
  dot.type = 'button';
  dot.className = 'cf__dot';
  dot.setAttribute('aria-label', DOT_LABEL.replace('{n}', i + 1));
  dot.addEventListener('click', picker(i));
  dotsBox.appendChild(dot);
  dots.push(dot);
}
document.getElementById('prev').addEventListener('click', function () { stop(); go(index - 1); });
document.getElementById('next').addEventListener('click', function () { stop(); go(index + 1); });
cf.addEventListener('keydown', function (e) {
  if (e.key === 'ArrowLeft') { stop(); go(index - 1); }
  if (e.key === 'ArrowRight') { stop(); go(index + 1); }
});
cf.addEventListener('pointerdown', stop);
go(0);
// 격자 미리보기: .is-demo 가 붙어 있는 동안만 혼자 넘어간다
timer = setInterval(function () { if (cf.classList.contains('is-demo')) { go(index + 1); } }, 440);

// CoverflowDepthSlider — vanilla 판(run/082/demo/03-slider-coverflow-depth-3d/index.html) 의 React 포트.
// 스크롤 위치가 아니라 "활성 장에서 몇 칸 떨어졌는가" 가 모양을 정한다.
// 컴포넌트는 카드마다 거리 d 와 |d| 만 CSS 변수로 얹고, rotateY·translateZ·축소는 CSS 가 계산한다.
import { useEffect, useState } from "react";
import type { CSSProperties } from "react";
import styles from "./CoverflowDepthSlider.module.scss";

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

type Vars = CSSProperties & {
  "--duration"?: string;
  "--easing"?: string;
  "--color"?: string;
};

type CardVars = CSSProperties & { "--d"?: number; "--ad"?: number };

const REGION_LABEL = "앨범 표지 깊이 슬라이더";
const SLIDE_LABEL = "{total}장 중 {n}장 · {name}";
const DOT_LABEL = "{n}번째 표지 보기";
const PREV_LABEL = "이전 표지";
const NEXT_LABEL = "다음 표지";

type Cover = { key: string; name: string; alt: string };

const COVERS: Cover[] = [
  { key: "a", name: "새벽 호수", alt: "물안개가 낮게 덮인 잔잔한 호수 표지" },
  { key: "b", name: "붉은 사막", alt: "해 질 무렵 붉게 물든 사막 바위 표지" },
  { key: "c", name: "밤의 정거장", alt: "불 켜진 승강장이 늘어선 밤 기차 정거장 표지" },
  { key: "d", name: "초록 언덕", alt: "비가 갠 뒤 젖은 초록 언덕과 낮은 구름 표지" },
  { key: "e", name: "얼음 바다", alt: "푸른 얼음 조각이 떠 있는 겨울 바다 표지" },
];

function CaretLeft() {
  return (
    <svg xmlns="http://www.w3.org/2000/svg" width="1em" height="1em" viewBox="0 0 256 256" aria-hidden="true">
      <g fill="currentColor">
        <path d="M160 48v160l-80-80Z" opacity=".2" />
        <path d="M163.06 40.61a8 8 0 0 0-8.72 1.73l-80 80a8 8 0 0 0 0 11.32l80 80A8 8 0 0 0 168 208V48a8 8 0 0 0-4.94-7.39M152 188.69L91.31 128L152 67.31Z" />
      </g>
    </svg>
  );
}

function CaretRight() {
  return (
    <svg xmlns="http://www.w3.org/2000/svg" width="1em" height="1em" viewBox="0 0 256 256" aria-hidden="true">
      <g fill="currentColor">
        <path d="m176 128l-80 80V48Z" opacity=".2" />
        <path d="m181.66 122.34l-80-80A8 8 0 0 0 88 48v160a8 8 0 0 0 13.66 5.66l80-80a8 8 0 0 0 0-11.32M104 188.69V67.31L164.69 128Z" />
      </g>
    </svg>
  );
}

export default function CoverflowDepthSlider(props: CoverflowDepthSliderProps) {
  const duration = props.duration ?? 600;
  const easing = props.easing ?? "ease-out";
  const color = props.color ?? "#2f6df6";
  const autoplayMs = props.autoplayMs ?? 440;
  const total = COVERS.length;
  const [index, setIndex] = useState<number>(0);
  const [playing, setPlaying] = useState<boolean>(true);

  useEffect(() => {
    if (!playing) return;
    const id = window.setInterval(() => setIndex((prev: number) => (prev + 1) % total), autoplayMs);
    return () => window.clearInterval(id);
  }, [playing, autoplayMs, total]);

  const stop = () => setPlaying(false);
  const go = (n: number) => {
    stop();
    setIndex(((n % total) + total) % total);
  };

  const vars: Vars = { "--duration": duration + "ms", "--easing": easing, "--color": color };

  return (
    <main className={styles.stage}>
      <section
        className={styles.cf}
        style={vars}
        tabIndex={0}
        role="region"
        aria-roledescription="carousel"
        aria-label={REGION_LABEL}
        onPointerDown={stop}
        onKeyDown={(e: { key: string }) => {
          if (e.key === "ArrowLeft") go(index - 1);
          if (e.key === "ArrowRight") go(index + 1);
        }}
      >
        <div className={styles.box}>
          <div className={styles.track}>
            {COVERS.map((cover: Cover, i: number) => {
              const d = i - index;
              const far = Math.abs(d);
              const cardVars: CardVars = { "--d": d, "--ad": far, zIndex: total - far, pointerEvents: far > 2 ? "none" : "auto" };
              const name = SLIDE_LABEL.replace("{n}", String(i + 1)).replace("{total}", String(total)).replace("{name}", cover.name);
              return (
                <button
                  key={cover.key}
                  className={styles.card}
                  style={cardVars}
                  type="button"
                  aria-roledescription="slide"
                  aria-label={name}
                  aria-current={d === 0 ? "true" : "false"}
                  onClick={() => go(i)}
                >
                  <span className={styles.art + " " + styles["art--" + cover.key]} role="img" aria-label={cover.alt} />
                  <span className={styles.name}>{cover.name}</span>
                </button>
              );
            })}
          </div>
        </div>
        <div className={styles.bar}>
          <button className={styles.nav} type="button" aria-label={PREV_LABEL} onClick={() => go(index - 1)}>
            <CaretLeft />
          </button>
          <div className={styles.dots}>
            {COVERS.map((cover: Cover, i: number) => (
              <button
                key={cover.key}
                className={styles.dot}
                type="button"
                aria-label={DOT_LABEL.replace("{n}", String(i + 1))}
                aria-current={i === index ? "true" : "false"}
                onClick={() => go(i)}
              />
            ))}
          </div>
          <button className={styles.nav} type="button" aria-label={NEXT_LABEL} onClick={() => go(index + 1)}>
            <CaretRight />
          </button>
        </div>
      </section>
    </main>
  );
}