/* ============================================================
   AirPods 5 Tutorial Demo — clean design system
   DARK universe (hero/film) + LIGHT universe (Apple.com style)
   Tutorial-friendly: each block is commented for the video
   ============================================================ */
:root{
  --bg:#000; --fg:#f5f5f7; --muted:#86868b; --accent:#2997ff;
  --card:#0b0b0e; --line:rgba(255,255,255,.12);
  --light-bg:#f5f5f7; --light-card:#ffffff; --ink:#1d1d1f; --ink-2:#6e6e73;
  --red:#fa1744;
  --r:18px; --max:1120px; --max-wide:1280px;
  --font:-apple-system,BlinkMacSystemFont,"SF Pro Display","Segoe UI",Inter,Roboto,"Helvetica Neue",Arial,sans-serif;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{background:var(--bg);color:var(--fg);font-family:var(--font);-webkit-font-smoothing:antialiased;overflow-x:hidden}
img{display:block;max-width:100%}
a{color:inherit;text-decoration:none}
button{font-family:inherit}

/* ---------- Loader ---------- */
#loader{position:fixed;inset:0;background:#000;z-index:200;display:flex;align-items:center;justify-content:center;transition:opacity .6s,visibility .6s}
#loader.done{opacity:0;visibility:hidden}
.loader-inner{text-align:center;width:min(320px,70vw)}
.loader-logo{font-weight:700;letter-spacing:.02em;margin-bottom:18px;font-size:20px}
.loader-logo span{display:block;font-weight:400;font-size:12px;color:var(--muted);letter-spacing:.2em;text-transform:uppercase;margin-top:6px}
.loader-bar{height:3px;background:#222;border-radius:99px;overflow:hidden}
.loader-bar span{display:block;height:100%;width:0;background:var(--accent);border-radius:99px;transition:width .2s}
.loader-pct{margin-top:10px;color:var(--muted);font-size:13px;font-variant-numeric:tabular-nums}
.loader-sub{margin-top:6px;color:#555;font-size:12px}

/* ---------- Nav ---------- */
#nav{position:fixed;top:0;left:0;right:0;z-index:100;display:flex;align-items:center;gap:24px;padding:14px 28px;background:rgba(0,0,0,.55);backdrop-filter:saturate(1.4) blur(18px);-webkit-backdrop-filter:saturate(1.4) blur(18px);border-bottom:1px solid var(--line)}
.brand{font-weight:700;font-size:15px;white-space:nowrap}
.brand span{background:#fff;color:#000;border-radius:6px;padding:0 5px;margin-left:2px}
.brand em{font-style:normal;font-weight:400;font-size:11px;color:var(--muted);border:1px solid var(--line);border-radius:99px;padding:2px 8px;margin-left:8px;letter-spacing:.08em;text-transform:uppercase}
#nav .links{display:flex;gap:20px;margin-left:auto;font-size:13px;color:var(--muted)}
#nav .links a:hover{color:var(--fg)}
.btn{display:inline-block;background:var(--accent);color:#fff;font-weight:600;font-size:15px;padding:12px 26px;border-radius:99px;border:0;cursor:pointer;transition:transform .15s,box-shadow .15s}
.btn:hover{transform:scale(1.03);box-shadow:0 8px 30px rgba(41,151,255,.35)}
.btn.small{font-size:13px;padding:8px 18px}
.btn.ghost{background:transparent;border:1px solid var(--line)}
.cta{display:flex;gap:14px;justify-content:center;flex-wrap:wrap}

/* ---------- Hero ---------- */
.hero{min-height:100svh;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:120px 24px 60px;position:relative}
.eyebrow{color:var(--accent);font-weight:600;font-size:14px;letter-spacing:.08em;text-transform:uppercase;margin-bottom:18px}
.hero h1{font-size:clamp(48px,9vw,110px);line-height:1.02;font-weight:700;letter-spacing:-.03em}
.hero .sub{color:var(--muted);font-size:clamp(16px,2.4vw,21px);line-height:1.5;margin:24px 0 34px}
.meta{display:flex;gap:10px 26px;flex-wrap:wrap;justify-content:center;margin-top:44px;color:var(--muted);font-size:13px}
.scroll-hint{position:absolute;bottom:26px;display:flex;flex-direction:column;align-items:center;gap:8px;color:var(--muted);font-size:12px;letter-spacing:.15em;text-transform:uppercase}
.scroll-hint span{width:1px;height:44px;background:linear-gradient(var(--muted),transparent);display:block;animation:hint 1.8s ease-in-out infinite}
@keyframes hint{0%,100%{transform:scaleY(.4);opacity:.4}50%{transform:scaleY(1);opacity:1}}

/* ---------- Theater (3D scroll film) ---------- */
.theater-wrap{height:420vh;position:relative}
.theater-sticky{position:sticky;top:0;height:100svh;overflow:hidden;background:#000}
#filmCanvas{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.grain{position:absolute;inset:0;pointer-events:none;opacity:.5;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)' opacity='.06'/%3E%3C/svg%3E")}
.chapter{position:absolute;left:50%;bottom:12%;transform:translateX(-50%);text-align:center;width:min(680px,88vw);opacity:0;transition:opacity .45s;pointer-events:none}
.chapter.on{opacity:1}
.ch-num{color:var(--accent);font-weight:600;font-size:13px;letter-spacing:.2em;text-transform:uppercase;margin-bottom:12px}
.chapter h2{font-size:clamp(34px,6vw,64px);line-height:1.05;font-weight:700;letter-spacing:-.02em;text-shadow:0 4px 40px rgba(0,0,0,.9)}
.ch-sub{color:#c9c9d1;margin-top:12px;font-size:clamp(14px,2vw,18px);text-shadow:0 2px 20px rgba(0,0,0,.9)}
.film-hud{position:absolute;left:50%;transform:translateX(-50%);bottom:26px;width:min(560px,80vw);display:flex;align-items:center;gap:14px}
.film-progress{flex:1;height:2px;background:rgba(255,255,255,.18);border-radius:99px;overflow:hidden}
.film-progress span{display:block;height:100%;width:0;background:#fff}
.film-frame{font-size:12px;color:var(--muted);font-variant-numeric:tabular-nums;letter-spacing:.1em}

/* ---------- Dark sections ---------- */
.section{max-width:var(--max);margin:0 auto;padding:130px 24px 30px}
.section.narrow{max-width:860px}
h2.big{font-size:clamp(36px,6vw,68px);line-height:1.05;letter-spacing:-.02em;font-weight:700;margin-bottom:54px}
.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:30px 26px;transition:transform .2s,border-color .2s}
.card:hover{transform:translateY(-4px);border-color:rgba(41,151,255,.5)}
.card h3{font-size:20px;margin-bottom:10px}
.card p{color:var(--muted);font-size:15px;line-height:1.55}
.banner{position:relative;max-width:1400px;margin:110px auto 0;border-radius:24px;overflow:hidden;aspect-ratio:16/8}
.banner img{width:100%;height:100%;object-fit:cover;object-position:50% 20%}
.banner img.pos-top{object-position:50% 8%}
.banner-text{position:absolute;inset:auto 0 0 0;padding:48px;text-align:center;background:linear-gradient(transparent,rgba(0,0,0,.72))}
.banner-text h2{font-size:clamp(24px,4vw,46px);letter-spacing:-.02em}
.anatomy{display:grid;grid-template-columns:1.4fr 1fr;gap:28px;align-items:start}
.anatomy-stage{position:relative;border-radius:var(--r);overflow:hidden;border:1px solid var(--line);background:#000}
.anatomy-stage img{width:100%;aspect-ratio:16/9;object-fit:cover}
.hotspot{position:absolute;left:var(--x);top:var(--y);width:34px;height:34px;transform:translate(-50%,-50%);background:transparent;border:0;cursor:pointer}
.hotspot span{display:block;width:14px;height:14px;margin:10px;border-radius:50%;background:var(--accent);box-shadow:0 0 0 5px rgba(41,151,255,.25);animation:pulse 2s infinite}
@keyframes pulse{50%{box-shadow:0 0 0 10px rgba(41,151,255,.08)}}
.hotspot-tip{position:absolute;left:50%;bottom:12px;transform:translateX(-50%);background:rgba(0,0,0,.75);border:1px solid var(--line);padding:8px 16px;border-radius:99px;font-size:13px;white-space:nowrap;max-width:90%;overflow:hidden;text-overflow:ellipsis}
.parts{list-style:none;display:flex;flex-direction:column;gap:14px}
.parts li{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:16px 18px}
.parts strong{display:block;font-size:15px;margin-bottom:4px}
.parts span{color:var(--muted);font-size:14px}
.mic{border-radius:var(--r);overflow:hidden;border:1px solid var(--line)}
.mic img{width:100%;aspect-ratio:16/9;object-fit:cover;object-position:50% 80%}
.specs{display:flex;flex-direction:column}
.specs div{display:grid;grid-template-columns:180px 1fr;gap:18px;padding:20px 4px;border-top:1px solid var(--line)}
.specs div:last-child{border-bottom:1px solid var(--line)}
.specs dt{color:var(--muted);font-size:14px}
.specs dd{font-size:15px;line-height:1.6}
.buy{display:grid;grid-template-columns:1fr 1fr;background:#f5f5f7;color:#111;border-radius:24px;overflow:hidden}
.buy-media img{width:100%;height:100%;object-fit:cover;aspect-ratio:1}
.buy-info{padding:56px 48px;display:flex;flex-direction:column;justify-content:center;gap:14px}
.buy-info .eyebrow{margin:0}
.buy-info h2{font-size:56px;letter-spacing:-.03em}
.buy-sub{color:#555;line-height:1.6}
.buy-note{font-size:13px;color:#888}

/* ============================================================
   LIGHT UNIVERSE — matches your 3 reference designs
   ============================================================ */
.light{background:var(--light-bg);color:var(--ink);margin-top:120px;padding-bottom:20px}
.light-section{max-width:var(--max-wide)}
.dark-eyebrow{color:var(--ink-2)}
.dark-h{color:var(--ink)}
.center{text-align:center}

/* --- Connectivity grid --- */
.connect-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:20px;align-items:stretch}
.connect-side{display:grid;gap:20px}
.light-card{background:var(--light-card);border-radius:28px;padding:40px;box-shadow:0 10px 40px rgba(0,0,0,.06);overflow:hidden}
.light-card h3{font-size:clamp(26px,3.4vw,38px);letter-spacing:-.02em;line-height:1.1;margin-top:28px;text-align:center}
.light-sub{text-align:center;color:var(--ink-2);font-size:15px;margin-top:10px}
.connect-hero{display:flex;flex-direction:column}
.connect-visual{position:relative;display:flex;justify-content:center;padding:10px 0 0;min-height:520px}
/* iPhone mock (pure CSS, tutorial-friendly) */
.iphone{width:270px;height:560px;background:#111;border-radius:48px;padding:10px;box-shadow:0 0 0 2px #c8c8ce,0 30px 60px rgba(0,0,0,.25);position:relative}
.iphone-notch{position:absolute;top:20px;left:50%;transform:translateX(-50%);width:110px;height:26px;background:#000;border-radius:99px;z-index:2}
.iphone-notch::after{content:"";position:absolute;right:14px;top:7px;width:12px;height:12px;border-radius:50%;background:#1a2a4a;box-shadow:inset 0 0 4px #000}
.iphone-screen{background:linear-gradient(180deg,#8a7a6a,#2b241f 60%,#111);border-radius:38px;height:100%;padding:44px 18px 18px;color:#fff;position:relative;overflow:hidden;display:flex;flex-direction:column}
.player-art{height:180px;border-radius:18px;background:radial-gradient(circle at 30% 30%,#f5c9a0,#9a6a52 45%,#3a2d26);margin-bottom:14px}
.player-title{font-weight:700;font-size:15px}
.player-title small{display:block;font-weight:400;color:#d8d0c8;font-size:13px}
.player-bar{height:4px;background:rgba(255,255,255,.3);border-radius:99px;margin:14px 0 6px;position:relative}
.player-bar span{position:absolute;left:0;top:0;bottom:0;width:62%;background:#fff;border-radius:99px}
.player-controls{display:flex;align-items:center;justify-content:space-around;margin:16px 0;font-size:22px}
.player-controls i{width:0;height:0;border-top:10px solid transparent;border-bottom:10px solid transparent;border-right:16px solid #fff;display:block}
.player-controls i.next{border-right:0;border-left:16px solid #fff}
.player-controls b{width:14px;height:26px;border-left:6px solid #fff;border-right:6px solid #fff;display:block}
.player-vol{height:4px;background:rgba(255,255,255,.3);border-radius:99px;position:relative;margin:10px 0 18px}
.player-vol span{position:absolute;left:0;top:0;bottom:0;width:45%;background:#fff;border-radius:99px}
.player-device{margin-top:auto;text-align:center;font-size:12px;color:#e8e2da}
.connect-case{position:absolute;right:0;bottom:40px;width:230px;filter:drop-shadow(0 20px 30px rgba(0,0,0,.3));border-radius:24px}
/* Share audio UI */
.share-ui{background:#8d96a3;border-radius:28px;padding:22px;color:#fff;max-width:340px;margin:0 auto}
.share-head{display:flex;gap:12px;align-items:center;margin-bottom:14px}
.share-art{width:52px;height:52px;border-radius:12px;background:radial-gradient(circle at 30% 30%,#f8d9b0,#7a5a48);flex:none}
.share-head strong{display:block;font-size:14px}
.share-head small{color:#e6e9ee;font-size:12px}
.share-users{margin-left:auto;background:rgba(255,255,255,.25);width:32px;height:32px;border-radius:50%;display:flex;align-items:center;justify-content:center}
.share-bar{height:5px;background:rgba(255,255,255,.35);border-radius:99px;margin-bottom:14px;position:relative}
.share-bar span{position:absolute;left:0;top:0;bottom:0;width:55%;background:#fff;border-radius:99px}
.share-row{display:flex;align-items:center;gap:8px;width:100%;background:rgba(255,255,255,.18);border:0;color:#fff;border-radius:16px;padding:10px 14px;font-size:13px;margin-top:8px;cursor:pointer;text-align:left}
.share-row small{color:#eef;font-size:11px;margin-left:4px}
.share-row em{margin-left:auto;font-style:normal;background:#1d1d1f;color:#fff;width:20px;height:20px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:12px}
.share-row.active{background:rgba(255,255,255,.75);color:#1d1d1f}
/* Auto switching pill */
.switch-visual{display:flex;flex-direction:column;align-items:center;gap:18px}
.switch-pill{display:flex;align-items:center;gap:14px;background:#000;color:#fff;border-radius:99px;padding:10px 28px 10px 10px;min-width:280px;box-shadow:0 14px 30px rgba(0,0,0,.25);transition:transform .3s}
.switch-pill img{width:84px;height:52px;object-fit:cover;border-radius:24px;background:#fff}
.switch-pill span{font-weight:600;font-size:18px}
.switch-devices{display:flex;gap:10px}
.switch-devices button{border:1px solid #d2d2d7;background:#f5f5f7;border-radius:99px;padding:8px 16px;font-size:13px;cursor:pointer}
.switch-devices button.on{background:#000;color:#fff;border-color:#000}

/* --- Care+ --- */
.care-logo{text-align:center;font-size:clamp(40px,6vw,64px);font-weight:700;letter-spacing:-.03em;margin-bottom:40px}
.care-logo strong{font-weight:800}
.care-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.care-card{display:flex;flex-direction:column;align-items:center;text-align:center;gap:22px;padding:70px 30px}
.care-card svg{width:110px;height:110px}
.care-card p{font-size:20px;line-height:1.4;color:var(--ink)}

/* --- What's in the Box --- */
.box-section{text-align:center}
.box-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin-top:20px;text-align:center}
.box-card{padding:60px 30px 40px}
.box-card img{height:300px;object-fit:contain;margin:0 auto 30px;mix-blend-mode:multiply}
.box-card figcaption{font-size:24px;font-weight:600}
.box-note{color:var(--ink-2);margin-top:22px;font-size:14px}

/* ---------- Footer / toast / reveal ---------- */
footer{max-width:var(--max);margin:120px auto 0;padding:40px 24px 60px;color:var(--muted);font-size:13px;line-height:1.7;border-top:1px solid var(--line)}
.foot-brand{color:var(--fg);font-weight:700;margin-bottom:10px}
.copy{margin-top:10px}
.toast{position:fixed;left:50%;bottom:30px;transform:translate(-50%,80px);background:#1c1c20;border:1px solid var(--line);padding:13px 24px;border-radius:99px;font-size:14px;opacity:0;transition:.35s;z-index:150;color:#fff}
.toast.show{transform:translate(-50%,0);opacity:1}
.reveal{opacity:0;transform:translateY(26px);transition:opacity .7s ease,transform .7s ease}
.reveal.in{opacity:1;transform:none}

@media (max-width:1020px){
  .connect-grid{grid-template-columns:1fr}
  .connect-visual{min-height:0}
  .connect-case{position:relative;width:200px;margin:-60px auto 0}
  .care-grid{grid-template-columns:1fr 1fr}
}
@media (max-width:860px){
  #nav .links{display:none}
  .brand em{display:none}
  .grid{grid-template-columns:1fr}
  .anatomy{grid-template-columns:1fr}
  .buy{grid-template-columns:1fr}
  .buy-info{padding:36px 28px}
  .specs div{grid-template-columns:1fr;gap:6px}
  .banner{border-radius:0;aspect-ratio:4/5}
  .theater-wrap{height:460vh}
  .care-grid{grid-template-columns:1fr}
  .box-grid{grid-template-columns:1fr}
  .light-card{padding:28px 20px}
}
@media (prefers-reduced-motion:reduce){
  .reveal{opacity:1;transform:none}
  html{scroll-behavior:auto}
}