:root {
  --bg: #f5f5f7;
  --surface: rgba(255,255,255,.8);
  --card: #ffffff;
  --text: #111827;
  --muted: #667085;
  --line: rgba(17,24,39,.12);
  --accent: #0071e3;
  --accent2: #6d5dfc;
  --shadow: 0 18px 60px rgba(0,0,0,.08);
}

html[data-theme="dark"] {
  --bg: #0b0d12;
  --surface: rgba(20,24,32,.82);
  --card: #151922;
  --text: #f7f8fb;
  --muted: #b7bfcc;
  --line: rgba(255,255,255,.14);
  --accent: #66b2ff;
  --accent2: #c084fc;
  --shadow: 0 18px 60px rgba(0,0,0,.45);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, "Noto Sans TC", sans-serif;
  color: var(--text);
  background: radial-gradient(circle at 15% 10%, rgba(0,113,227,.18), transparent 30%),
              radial-gradient(circle at 85% 20%, rgba(109,93,252,.16), transparent 34%),
              var(--bg);
  line-height: 1.65;
}

.topbar {
  position: sticky; 
  top: 0; 
  z-index: 100;
  display: flex; 
  align-items: center; 
  gap: 14px;
  padding: 14px min(5vw, 64px);
  background: var(--surface); 
  backdrop-filter: blur(22px);
  -webkit-backdrop-filter: blur(22px);
  border-bottom: 1px solid var(--line);
}

.brand { display:flex; align-items:center; gap:10px; text-decoration:none; color:var(--text); font-weight:800; }

.logo-container {
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.nav { margin-left:auto; display:flex; gap:18px; align-items:center; }
.nav a { text-decoration:none; color:var(--muted); font-weight:650; font-size:.94rem; transition: color 0.25s ease; }
.nav a:hover { color: var(--accent); }

.tools { display:flex; gap:8px; align-items: center; }
.tool, .hamburger {
  border:1px solid var(--line); 
  background:var(--card); 
  color:var(--text);
  border-radius:999px; 
  padding:8px 12px; 
  font-weight:700; 
  cursor:pointer;
  transition: all 0.2s ease;
}
.tool:hover {
  background: var(--bg);
  border-color: var(--text);
}

.hamburger { display:none; width:44px; height:38px; border-radius:14px; padding:6px; }
.hamburger span { display:block; height:2px; background:var(--text); margin:6px; }

.hero {
  min-height: calc(100vh - 68px);
  display: grid;
  grid-template-columns: 1.25fr .75fr;
  gap: 42px;
  align-items: center;
  padding: 80px min(5vw,64px);
  background: linear-gradient(rgba(245,245,247,0.82), rgba(245,245,247,0.82)), url("apple-bg.jpg");
  background-size: cover;
  background-position: center;
  border-radius: 0 0 36px 36px;
}

html[data-theme="dark"] .hero {
  background: linear-gradient(rgba(11, 13, 18, 0.85), rgba(11, 13, 18, 0.85)), url("apple-bg.jpg");
  background-size: cover;
  background-position: center;
}

.eyebrow, .section-label { color:var(--accent); text-transform:uppercase; letter-spacing:.13em; font-weight:900; font-size:.78rem; margin:0 0 10px; }
.hero h1 { font-size:clamp(2.8rem,5.5vw,5.2rem); line-height:.95; letter-spacing:-.05em; margin:0 0 22px; color: var(--text); }
.hero-copy .hero-text { color: var(--muted); font-size:1.18rem; max-width:760px; }
.hero-actions { display:flex; flex-wrap:wrap; gap:12px; margin-top:28px; }

.btn { display:inline-block; border-radius:999px; padding:11px 18px; text-decoration:none; border:1px solid var(--line); font-weight:800; cursor:pointer; transition: transform 0.2s ease, box-shadow 0.2s ease; }
.btn:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0,0,0,0.1); }
.primary { background:var(--accent); color:white; border-color:var(--accent); }
.secondary { background:var(--card); color:var(--text); }

.iphone-card { border-radius:42px; padding:12px; background:linear-gradient(135deg,#222,#777); box-shadow:var(--shadow); transform:rotate(2deg); }
.screen { min-height:460px; border-radius:34px; background:var(--card); border:1px solid var(--line); display:flex; flex-direction:column; align-items:center; justify-content:center; text-align:center; padding:30px; }

.apple-logo-container {
  width: 85px;
  height: 85px;
  margin: 0 auto 20px auto;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent !important;
}

.logo-container img,
.apple-logo-container img {
  width: 100%;
  height: 100%;
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
  display: block;
}

html[data-theme="dark"] .logo-container img,
html[data-theme="dark"] .apple-logo-img { 
  filter: invert(1);
}

.screen h2 { font-size:2.5rem; margin:10px 0; }

.section { max-width:1240px; margin:0 auto; padding:82px min(5vw,64px); }
.section-head { max-width:850px; margin-bottom:30px; }
h2 { font-size:clamp(2rem,4vw,3.4rem); line-height:1.05; letter-spacing:-.04em; margin:0 0 14px; }

.quick-nav { display:grid; grid-template-columns:repeat(6,1fr); gap:14px; padding-top:20px; }
.quick-nav a { min-height:120px; background:var(--card); border:1px solid var(--line); border-radius:24px; padding:20px; display:flex; flex-direction:column; justify-content:space-between; color:var(--text); text-decoration:none; box-shadow:0 8px 25px rgba(0,0,0,.04); transition: transform 0.25s ease, box-shadow 0.25s ease; }
.quick-nav a:hover { transform: translateY(-4px); box-shadow: 0 12px 30px rgba(0,0,0,0.1); border-color: var(--accent); }
.quick-nav b { color:var(--accent); }

.team-grid, .metrics, .jobs-grid, .flip-grid, .org-grid { display:grid; gap:18px; }
.team-grid, .metrics { grid-template-columns:repeat(4,1fr); }
.member, .metric, .glass-card, .job-card, .summary-card, .quiz-card, .disclosure { background:var(--surface); border:1px solid var(--line); border-radius:28px; padding:24px; box-shadow:var(--shadow); }

.avatar { width:58px; height:58px; border-radius:18px; display:grid; place-items:center; color:white; background:linear-gradient(135deg,var(--accent),var(--accent2)); font-weight:900; font-size:1.4rem; overflow: hidden; }
.member-photo { width: 100%; aspect-ratio: 1 / 1; object-fit: cover; border-radius: 22px; margin-bottom: 14px; }
.member p, .job-card p, .summary-card li, .disclosure li { color:var(--muted); }

.split { display:grid; grid-template-columns:.9fr 1.1fr; gap:44px; align-items:start; }
.timeline { display:grid; gap:14px; }
.timeline-item { background:var(--card); border:1px solid var(--line); border-radius:24px; padding:22px; }
.timeline-item b { color:var(--accent); }

.org-grid { grid-template-columns:repeat(2,1fr); }
.metric b { display:block; font-size:2rem; margin-top:6px; }
.metric small { color:var(--muted); }

.jobs-grid { grid-template-columns:repeat(2,1fr); }
.job-card details { margin-top:12px; background: rgba(0,0,0,0.02); border-radius: 14px; padding: 6px 12px; }
html[data-theme="dark"] .job-card details { background: rgba(255,255,255,0.03); }
.job-card summary { cursor:pointer; font-weight:900; color:var(--accent); outline: none; padding: 4px 0; }
.pills { display:flex; flex-wrap:wrap; gap:8px; margin:12px 0; }
.pill { border-radius:999px; padding:5px 10px; background:rgba(0,113,227,.1); color:var(--accent); font-size:.82rem; font-weight:800; }

.flip-grid { grid-template-columns:repeat(3,1fr); }
.flip-card { min-height:220px; perspective:1000px; }
.flip-inner { position:relative; height:220px; transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1); transform-style:preserve-3d; }
.flip-card:hover .flip-inner, .flip-card:focus-within .flip-inner { transform:rotateY(180deg); }
.flip-front, .flip-back { position:absolute; inset:0; backface-visibility:hidden; -webkit-backface-visibility: hidden; border-radius:28px; display:grid; place-items:center; text-align:center; padding:24px; border:1px solid var(--line); background:var(--card); }
.flip-front { background:linear-gradient(135deg,rgba(0,113,227,.14),rgba(109,93,252,.16)),var(--card); }
.flip-back { transform:rotateY(180deg); color:var(--muted); }

.quiz-section { max-width:900px; }
.answers { display:grid; gap:10px; margin:18px 0; }
.answers button { text-align:left; border:1px solid var(--line); border-radius:16px; padding:12px; background:var(--card); color:var(--text); cursor:pointer; font-weight: 600; transition: background-color 0.2s ease; }
.answers button:hover:not(:disabled) { background: var(--bg); }
.answers button.correct { border-color:#22c55e; background:rgba(34,197,94,.15); color: #22c55e; }
.answers button.wrong { border-color:#ef4444; background:rgba(239,68,68,.15); color: #ef4444; }
.feedback { min-height:28px; font-weight:900; }

.reveal {
  opacity: 0;
  transform: translateY(35px);
  transition: opacity 0.8s cubic-bezier(0.25, 1, 0.5, 1), transform 0.8s cubic-bezier(0.25, 1, 0.5, 1);
}
.reveal.show {
  opacity: 1;
  transform: translateY(0);
}

footer { text-align:center; border-top:1px solid var(--line); padding:44px 24px; color:var(--muted); }
footer a { color: var(--accent); text-decoration: none; word-break: break-all; font-weight: 500; }
footer a:hover { text-decoration: underline; }
.top-btn { position:fixed; right:18px; bottom:18px; width:46px; height:46px; border:0; border-radius:50%; background:var(--accent); color:white; font-size:1.2rem; box-shadow:var(--shadow); cursor:pointer; transition: transform 0.2s ease; z-index: 90; }
.top-btn:hover { transform: scale(1.1); }

@media(max-width:980px){
  .hamburger{display:block; margin-left:auto;}
  .nav{display:none; position:absolute; left:16px; right:16px; top:68px; margin:0; background:var(--surface); backdrop-filter: blur(25px); -webkit-backdrop-filter: blur(25px); border:1px solid var(--line); border-radius:24px; padding:18px; flex-direction:column; align-items:stretch; box-shadow:var(--shadow);}
  .nav.open{display:flex;}
  .hero, .split, .org-grid, .jobs-grid{grid-template-columns:1fr;}
  .quick-nav{grid-template-columns:repeat(3,1fr);}
  .team-grid, .metrics, .flip-grid{grid-template-columns:repeat(2,1fr);}
  .hero { text-align: center; padding-top: 40px; }
  .hero-actions { justify-content: center; }
  .iphone-card { max-width: 420px; margin: 0 auto; transform: rotate(0deg); }
}

@media(max-width:640px){
  .brand span:last-child{display:none;}
  .tools{gap:5px;}
  .tool{padding:7px 9px; font-size:.82rem;}
  .hero, .section{padding-left:18px; padding-right:18px;}
  .quick-nav, .team-grid, .metrics, .flip-grid{grid-template-columns:1fr;}
  .hero h1{font-size:2.4rem;}
  .screen{min-height:330px;}
}