:root {
  --a1: #ff6a3d;
  --a2: #ffb547;
  --a3: #5eead4;
  --radius: 18px;
  --maxw: 1080px;
  --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", "Cascadia Code", Consolas, "SFMono-Regular", Menlo, monospace;
}
:root[data-theme="dark"] {
  --bg: #0b0d12; --bg2: #12151c;
  --card: rgba(255, 255, 255, 0.04); --card-b: rgba(255, 255, 255, 0.1);
  --text: #eef0f4; --muted: #a3acba; --line: rgba(255, 255, 255, 0.12);
  --nav: rgba(11, 13, 18, 0.8); --spot: rgba(255, 122, 69, 0.11);
}
:root[data-theme="light"] {
  --bg: #f7f5f2; --bg2: #ffffff;
  --card: rgba(255, 255, 255, 0.9); --card-b: rgba(17, 20, 27, 0.1);
  --text: #15171c; --muted: #555e6c; --line: rgba(17, 20, 27, 0.12);
  --nav: rgba(247, 245, 242, 0.85); --spot: rgba(255, 122, 69, 0.1);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body {
  margin: 0; background: var(--bg); color: var(--text); font-family: var(--font);
  line-height: 1.75; -webkit-font-smoothing: antialiased; overflow-x: hidden;
  background-image: linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 64px 64px; background-attachment: fixed;
}
body::before { content: ""; position: fixed; inset: 0; background: radial-gradient(ellipse at top, transparent 0%, var(--bg) 70%); pointer-events: none; z-index: -1; }
a { color: inherit; }
button { font: inherit; color: inherit; }
.spotlight { position: fixed; inset: 0; pointer-events: none; z-index: 0; background: radial-gradient(520px circle at var(--mx, 50%) var(--my, 30%), var(--spot), transparent 60%); }
.progress { position: fixed; top: 0; left: 0; height: 3px; width: 0; z-index: 60; background: linear-gradient(90deg, var(--a1), var(--a2)); }

/* NAV */
.nav {
  position: sticky; top: 0; z-index: 50; display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 12px max(16px, calc((100vw - var(--maxw)) / 2));
  background: var(--nav); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--card-b);
}
.brand { font-weight: 800; font-size: 20px; text-decoration: none; }
.brand span { color: var(--a1); }
.nav-links { display: flex; gap: 24px; }
.nav-links a { text-decoration: none; color: var(--muted); font-size: 15px; transition: color .2s; white-space: nowrap; }
.nav-links a:hover, .nav-links a.active { color: var(--text); }
.nav-actions { display: flex; gap: 8px; align-items: center; }
.icon-btn { border: 1px solid var(--card-b); background: var(--card); border-radius: 10px; padding: 6px 10px; cursor: pointer; font-size: 14px; }

main { position: relative; z-index: 1; max-width: var(--maxw); margin: 0 auto; padding: 0 16px; }

/* BUTTONS */
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 12px 22px; border-radius: 12px;
  font-weight: 700; text-decoration: none; cursor: pointer; border: 1px solid transparent;
  transition: transform .15s, border-color .2s;
}
.btn:hover { transform: translateY(-2px); }
.btn.small { padding: 6px 14px; font-size: 14px; border-radius: 10px; }
.btn.primary { background: linear-gradient(100deg, var(--a1), var(--a2)); color: #1a0d05; box-shadow: 0 8px 26px -12px var(--a1); }
.btn.ghost { border-color: var(--line); background: var(--card); }
.btn.ghost:hover { border-color: var(--a1); }

/* HERO */
.hero { display: grid; grid-template-columns: 250px 1fr; gap: 48px; align-items: center; padding: 48px 0 28px; }
.hero-photo { perspective: 1000px; }
.tilt { position: relative; width: 100%; border-radius: 24px; transition: transform .2s ease-out; }
.tilt::before {
  content: ""; position: absolute; inset: -2px; border-radius: 26px; z-index: -1;
  background: conic-gradient(from var(--ang, 0deg), var(--a1), var(--a2), var(--a3), var(--a1));
  animation: spin 7s linear infinite;
}
@property --ang { syntax: "<angle>"; initial-value: 0deg; inherits: false; }
@keyframes spin { to { --ang: 360deg; } }
.tilt img { display: block; width: 100%; height: auto; border-radius: 22px; }
.glare { position: absolute; inset: 0; border-radius: 22px; pointer-events: none; background: radial-gradient(circle at var(--gx, 50%) var(--gy, 0%), rgba(255,255,255,.2), transparent 55%); mix-blend-mode: overlay; }
.kicker { margin: 0; color: var(--muted); font-size: 18px; }
/* Desktop: the pitch line leads, the name stays readable but not poster-sized. */
h1 { font-size: 40px; line-height: 1.15; margin: 2px 0 12px; letter-spacing: -.5px; }
.grad { background: linear-gradient(100deg, var(--a1), var(--a2) 60%, var(--a3)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.headline { font-size: clamp(22px, 2.6vw, 30px); line-height: 1.5; margin: 0 0 20px; font-weight: 700; }
.tags { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; padding: 0; margin: 0 0 24px; }
.tags li { padding: 5px 14px; border-radius: 999px; border: 1px solid var(--card-b); background: var(--card); font-size: 14px; }
.cta, .contact-row { display: flex; gap: 12px; flex-wrap: wrap; }
.hero-meta { color: var(--muted); font-size: 14px; margin: 16px 0 0; }

/* STATS */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin: 8px 0 10px; }
.stat { padding: 20px; border-radius: var(--radius); background: var(--card); border: 1px solid var(--card-b); }
.stat b { display: block; font-size: 34px; line-height: 1.15; background: linear-gradient(100deg, var(--a1), var(--a2)); -webkit-background-clip: text; background-clip: text; color: transparent; font-variant-numeric: tabular-nums; }
.stat span { color: var(--muted); font-size: 14px; }

/* SECTIONS */
.section { padding: 72px 0 10px; }
.step { margin: 0 0 6px; font-size: 14px; font-weight: 700; color: var(--a1); letter-spacing: .5px; }
h2 { font-size: clamp(26px, 3.4vw, 36px); line-height: 1.3; margin: 0 0 10px; }
h2 small { display: inline-block; font-size: 15px; font-weight: 400; color: var(--muted); margin-left: 10px; }
.lead { color: var(--muted); font-size: 17px; margin: 0 0 24px; max-width: 760px; }
.lead b { color: var(--text); }
.card { position: relative; padding: 24px; border-radius: var(--radius); background: var(--card); border: 1px solid var(--card-b); }

/* NOW */
.feature-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.feature .meta { font-size: 13px; color: var(--a2); }
.feature h3 { margin: 2px 0 8px; font-size: 22px; }
.feature .what { margin: 0 0 14px; font-size: 16px; }
.feature .label { margin: 14px 0 4px; font-size: 13px; font-weight: 700; color: var(--muted); }
.feature .did { margin: 0; padding-left: 20px; }
.feature .did li { margin: 2px 0; }
.feature .value { margin: 0; color: var(--text); }
.more { margin-top: 16px; padding: 0; background: none; border: 0; cursor: pointer; color: var(--a2); font-weight: 700; }
.more:hover { text-decoration: underline; }
.also { list-style: none; padding: 0; margin: 18px 0 0; display: grid; gap: 10px; }
.also li { padding: 14px 18px; border-radius: 14px; background: var(--card); border: 1px dashed var(--line); color: var(--muted); }
.also b { color: var(--text); }

/* CASE STUDY */
.sub { margin: 34px 0 12px; font-size: 19px; }
.sub small { font-weight: 400; font-size: 14px; color: var(--muted); }
.pain { display: grid; grid-template-columns: repeat(5, 1fr); gap: 12px; }
.pain-item { padding: 16px; border-radius: 14px; background: var(--card); border: 1px solid var(--card-b); display: flex; flex-direction: column; gap: 4px; }
.pain-item b { color: var(--a2); }
.pain-item span { color: var(--muted); font-size: 14px; line-height: 1.6; }
.stages { display: grid; grid-template-columns: repeat(8, 1fr); gap: 8px; margin-bottom: 12px; counter-reset: s; }
.stage {
  position: relative; padding: 10px 6px; border-radius: 12px; cursor: pointer; font-size: 14px; font-weight: 700;
  background: var(--card); border: 1px solid var(--card-b); display: flex; flex-direction: column; align-items: center; gap: 4px; transition: all .2s;
}
.stage span { width: 24px; height: 24px; border-radius: 50%; display: grid; place-items: center; font-size: 12px; background: var(--bg2); border: 1px solid var(--line); }
.stage:not(:last-child)::after { content: "→"; position: absolute; right: -9px; top: 50%; transform: translateY(-50%); color: var(--muted); font-size: 12px; }
.stage:hover { border-color: var(--a1); }
.stage.active { border-color: var(--a1); background: rgba(255,106,61,.1); }
.stage.active span { background: linear-gradient(135deg, var(--a1), var(--a2)); color: #1a0d05; border: 0; }
.stage-detail b { color: var(--a2); }
.stage-detail p { margin: 6px 0 0; }
.ai-split { display: grid; grid-template-columns: 1.3fr 1fr; gap: 16px; }
.ai-split ul { margin: 0; padding-left: 20px; }
.ai-split li { margin: 6px 0; }
.ai-split .label { margin: 0 0 6px; font-weight: 800; }
.ok-label { color: #22c55e; }
.no-label { color: #f87171; }
.verify { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; align-items: start; }
.iter { margin: 0; padding-left: 20px; }
.iter li { margin: 8px 0; }
.evidence { display: grid; grid-template-columns: 1fr 1fr; gap: 6px 14px; }
.evidence p { grid-column: 1 / -1; margin: 6px 0 0; color: var(--muted); font-size: 15px; }
.ev-num b { display: block; font-size: 32px; line-height: 1.1; background: linear-gradient(100deg, var(--a1), var(--a2)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.ev-num span { color: var(--muted); font-size: 14px; }
.ev-chain { color: var(--text) !important; font-weight: 600; }

/* VIDEO */
.video-wrap { display: grid; grid-template-columns: 360px 1fr; gap: 32px; align-items: start; }
.player { position: relative; margin: 0; }
.player video { display: block; width: 100%; aspect-ratio: 3 / 4; border-radius: 18px; background: #000; border: 1px solid var(--card-b); }
.player figcaption { margin-top: 8px; font-size: 13px; color: var(--muted); }
.sound { position: absolute; left: 12px; top: 12px; padding: 6px 12px; border-radius: 999px; border: 0; cursor: pointer; font-size: 13px; font-weight: 700; background: rgba(0,0,0,.6); color: #fff; backdrop-filter: blur(6px); }
.video-info .label { margin: 16px 0 4px; font-size: 13px; font-weight: 700; color: var(--muted); }
.video-info .hw .label { margin-top: 0; }
.video-info .hw p { margin: 0; }
.hw b { color: var(--a2); }
.tight { margin: 0; padding-left: 20px; }
.tight li { margin: 4px 0; }
.muted-sm { color: var(--muted); font-size: 14px; margin: 10px 0 0; }
.modal-box img { width: 100%; border-radius: 12px; margin-top: 10px; }

/* TIMELINE */
.timeline { list-style: none; margin: 0; padding: 0 0 0 26px; position: relative; }
.timeline::before { content: ""; position: absolute; left: 6px; top: 6px; bottom: 6px; width: 2px; background: linear-gradient(var(--a1), var(--a3)); }
.timeline li { position: relative; padding: 0 0 30px 18px; }
.timeline li::before { content: ""; position: absolute; left: -26px; top: 8px; width: 14px; height: 14px; border-radius: 50%; background: var(--bg); border: 3px solid var(--a1); }
.timeline li.now::before { background: var(--a1); box-shadow: 0 0 0 6px rgba(255,106,61,.2); }
.timeline time { font-size: 14px; color: var(--a2); font-weight: 700; }
.badge { margin-left: 8px; padding: 1px 8px; border-radius: 6px; font-size: 12px; background: rgba(34,197,94,.15); color: #22c55e; }
.timeline h3 { margin: 2px 0 4px; font-size: 20px; }
.timeline small { font-weight: 400; color: var(--muted); font-size: 14px; margin-left: 6px; }
.timeline p { margin: 0 0 10px; }
.proj-links { display: flex; flex-wrap: wrap; gap: 8px; }
.proj-link { padding: 5px 12px; border-radius: 8px; cursor: pointer; font-size: 14px; background: var(--bg2); border: 1px solid var(--card-b); transition: border-color .2s; }
.proj-link::after { content: " →"; color: var(--a2); }
.proj-link:hover { border-color: var(--a1); }
.reveal { opacity: 0; transform: translateY(16px); transition: opacity .6s, transform .6s; }
.reveal.in { opacity: 1; transform: none; }

/* AI DEV */
.tools { display: flex; flex-wrap: wrap; gap: 10px; margin: 0 0 18px; }
.tool { padding: 8px 15px; border-radius: 12px; font-size: 14px; font-weight: 700; background: var(--bg2); border: 1px solid var(--a1); color: var(--text); }
.how { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.how h3 { margin: 10px 0 6px; font-size: 18px; }
.how p { margin: 0; color: var(--muted); }
.num { display: inline-grid; place-items: center; width: 30px; height: 30px; border-radius: 50%; font-weight: 800; color: #1a0d05; background: linear-gradient(135deg, var(--a1), var(--a2)); }

/* SKILLS */
.skills { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 14px; }
.skill-group { padding: 18px 20px; border-radius: var(--radius); background: var(--card); border: 1px solid var(--card-b); }
.skill-group h3 { margin: 0 0 10px; font-size: 16px; }
.skill-group .list { display: flex; flex-wrap: wrap; gap: 8px; }
.skill { padding: 4px 10px; border-radius: 8px; font-size: 13px; background: var(--bg2); border: 1px solid var(--card-b); }

/* CONTACT */
.contact { text-align: center; }
.contact .lead { margin-left: auto; margin-right: auto; }
.contact-row { justify-content: center; }
.mail-text { font-family: var(--mono); color: var(--muted); margin-top: 14px; }

/* EASTER EGG */
.egg { padding-bottom: 50px; }
.egg summary { cursor: pointer; color: var(--muted); font-size: 15px; padding: 12px 16px; border-radius: 12px; border: 1px dashed var(--line); width: fit-content; margin: 0 auto 16px; list-style: none; }
.egg summary::-webkit-details-marker { display: none; }
.egg summary:hover { color: var(--text); border-color: var(--a1); }
.term { border-radius: var(--radius); overflow: hidden; border: 1px solid var(--card-b); background: #07080c; color: #d7dde8; font-family: var(--mono); font-size: 14px; }
.term-bar { display: flex; align-items: center; gap: 7px; padding: 10px 14px; background: #12151d; }
.term-bar i { width: 12px; height: 12px; border-radius: 50%; background: #ff5f57; }
.term-bar i:nth-child(2) { background: #febc2e; }
.term-bar i:nth-child(3) { background: #28c840; }
.term-bar span { margin-left: 10px; color: #7d8696; font-size: 13px; }
.term-body { padding: 16px; height: 260px; overflow-y: auto; white-space: pre-wrap; line-height: 1.6; }
.term-body .p { color: #ff9b6a; }
.term-body .ok { color: #5eead4; }
.term-input { display: flex; gap: 8px; align-items: center; padding: 10px 16px; border-top: 1px solid #1d2230; }
.term-input label { color: #ff9b6a; }
.term-input input { flex: 1; background: transparent; border: 0; outline: none; color: #eef0f4; font: inherit; }
.term-hints { display: flex; flex-wrap: wrap; gap: 6px; padding: 0 16px 14px; }
.term-hints button { background: #12151d; border: 1px solid #222838; color: #b9c2d0; border-radius: 6px; padding: 3px 9px; cursor: pointer; font-family: var(--mono); font-size: 12px; }

/* FAB, FOOTER, MODAL, TOAST */
.fab {
  position: fixed; right: 20px; bottom: 20px; z-index: 40; padding: 12px 18px; border-radius: 999px; font-weight: 700; text-decoration: none;
  background: linear-gradient(100deg, var(--a1), var(--a2)); color: #1a0d05; box-shadow: 0 10px 30px -10px rgba(0,0,0,.6);
  opacity: 0; transform: translateY(20px); pointer-events: none; transition: all .3s;
}
.fab.show { opacity: 1; transform: none; pointer-events: auto; }
.footer { text-align: center; color: var(--muted); font-size: 13px; padding: 26px 16px 36px; border-top: 1px solid var(--card-b); position: relative; z-index: 1; }
.modal { position: fixed; inset: 0; z-index: 80; background: rgba(5,6,10,.6); backdrop-filter: blur(6px); display: grid; place-items: center; padding: 16px; }
.modal[hidden] { display: none; }
.modal-box { position: relative; width: min(680px, 100%); max-height: 86vh; overflow: auto; background: var(--bg2); border: 1px solid var(--card-b); border-radius: 20px; padding: 30px; }
.modal-box h3 { margin: 0 0 8px; font-size: 23px; }
.modal-box .meta { color: var(--a2); font-size: 13px; }
.modal-box .what { margin: 0 0 6px; }
.modal-box ul { padding-left: 20px; color: var(--muted); }
.modal-box li { margin: 8px 0; }
.tags-row { display: flex; flex-wrap: wrap; gap: 6px; }
.tag { font-size: 12px; padding: 3px 9px; border-radius: 6px; border: 1px solid var(--card-b); color: var(--muted); }
.modal-close { position: absolute; top: 12px; right: 14px; border: 0; background: transparent; font-size: 26px; cursor: pointer; color: var(--muted); }
.toast { position: fixed; left: 50%; bottom: 30px; transform: translate(-50%, 30px); opacity: 0; z-index: 90; background: var(--text); color: var(--bg); padding: 10px 18px; border-radius: 10px; font-weight: 700; transition: all .3s; pointer-events: none; }
.toast.show { opacity: 1; transform: translate(-50%, 0); }

/* RESPONSIVE */
@media (max-width: 900px) {
  .nav { flex-wrap: wrap; row-gap: 6px; }
  .nav-links { order: 3; width: 100%; gap: 20px; overflow-x: auto; padding-bottom: 2px; scrollbar-width: none; }
  .nav-links::-webkit-scrollbar { display: none; }
  .hero { grid-template-columns: 112px 1fr; gap: 18px 20px; padding: 28px 0 16px; align-items: start; }
  .hero-photo { grid-column: 1; grid-row: 1 / span 2; }
  .tilt img { border-radius: 18px; }
  .hero-text { display: contents; }
  .kicker { grid-column: 2; grid-row: 1; align-self: end; }
  h1 { grid-column: 2; grid-row: 2; margin: 0; align-self: start; font-size: 44px; letter-spacing: -1px; }
  .headline, .tags, .cta, .hero-meta { grid-column: 1 / -1; }
  .headline { margin: 0; font-size: 19px; font-weight: 600; }
  .tags, .cta { margin: 0; }
  .hero-meta { margin: 0; }
  .br-wide { display: none; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .feature-grid, .how, .ai-split, .verify, .video-wrap { grid-template-columns: 1fr; }
  .player { max-width: 420px; }
  .pain { grid-template-columns: 1fr 1fr; }
  .stages { grid-template-columns: repeat(4, 1fr); }
  .stage:nth-child(4)::after { display: none; }
  .section { padding-top: 56px; }
}
@media (max-width: 420px) {
  .stat b { font-size: 28px; }
  .btn { padding: 11px 16px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
  .reveal { opacity: 1; transform: none; }
}