:root {
  --ink: #252421;
  --ink-2: #4a453d;
  --ink-3: #837a6d;
  --paper: #f7f4ee;
  --paper-2: #fffdf8;
  --cinnabar: #b52627;
  --line: rgba(37, 36, 33, 0.14);
  --line-strong: rgba(37, 36, 33, 0.28);
  --serif: "Noto Serif SC", "Songti SC", "Source Han Serif SC", STSong, serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --display: "Fraunces", var(--serif);
  --pad: clamp(20px, 5vw, 88px);
  --maxw: 1180px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; cursor: pointer; }

h1, h2, h3, h4 {
  font-family: var(--serif);
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.16;
  margin: 0;
}

em { font-style: normal; }
::selection { background: var(--cinnabar); color: var(--paper-2); }

.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 999;
  opacity: 0.4;
  mix-blend-mode: multiply;
  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='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)' opacity='0.28'/%3E%3C/svg%3E");
}

.progress { position: fixed; top: 0; left: 0; right: 0; height: 2px; z-index: 200; }
.progress span { display: block; height: 100%; width: 0; background: var(--cinnabar); transition: width 0.1s linear; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin: 0 0 22px;
}
.eyebrow .dot {
  width: 7px; height: 7px;
  background: var(--cinnabar);
  border-radius: 50%;
  box-shadow: 0 0 0 0 rgba(181, 38, 39, 0.5);
  animation: pulse 2.6s var(--ease) infinite;
}
.eyebrow.light { color: rgba(255, 253, 248, 0.65); }
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(181, 38, 39, 0.45); }
  70% { box-shadow: 0 0 0 12px rgba(181, 38, 39, 0); }
  100% { box-shadow: 0 0 0 0 rgba(181, 38, 39, 0); }
}

.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 150;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px var(--pad);
  border-bottom: 1px solid transparent;
  transition: background 0.4s var(--ease), padding 0.4s var(--ease), border-color 0.4s var(--ease);
}
.nav.scrolled {
  background: rgba(247, 244, 238, 0.82);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  padding-top: 10px;
  padding-bottom: 10px;
  border-bottom-color: var(--line);
}
.brand { display: inline-flex; align-items: center; }
.brand-logo { height: 30px; width: auto; display: block; transition: transform 0.4s var(--ease); }
.brand:hover .brand-logo { transform: translateY(-1px); }
.brand-logo.zh { display: none; }
html[data-lang="zh"] .brand-logo.en { display: none; }
html[data-lang="zh"] .brand-logo.zh { display: block; }
.brand-foot .brand-logo { height: 34px; }

.nav-links { display: flex; gap: 34px; }
.nav-links a { font-size: 14px; color: var(--ink-2); position: relative; padding: 4px 0; }
.nav-links a::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  width: 0; height: 1px;
  background: var(--cinnabar);
  transition: width 0.35s var(--ease);
}
.nav-links a:hover { color: var(--ink); }
.nav-links a:hover::after { width: 100%; }

.nav-cta { display: flex; align-items: center; gap: 14px; }
.lang {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  padding: 4px;
  border: 1px solid var(--line-strong);
  border-radius: 100px;
  background: transparent;
}
.lang span {
  font-size: 12px;
  letter-spacing: 0.1em;
  padding: 3px 10px;
  border-radius: 100px;
  color: var(--ink-3);
  transition: background 0.3s var(--ease), color 0.3s var(--ease);
}
.lang span.on { background: var(--ink); color: var(--paper-2); }
.lang-foot { border-color: var(--line); }
.lang-foot span.on { background: var(--cinnabar); }

.menu-btn {
  display: none;
  width: 42px; height: 42px;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  background: transparent;
  position: relative;
}
.menu-btn span {
  position: absolute; left: 12px; right: 12px; height: 1.5px;
  background: var(--ink);
  transition: transform 0.35s var(--ease);
}
.menu-btn span:first-child { top: 17px; }
.menu-btn span:last-child { top: 24px; }
.menu-btn[aria-expanded="true"] span:first-child { transform: translateY(3.5px) rotate(45deg); }
.menu-btn[aria-expanded="true"] span:last-child { transform: translateY(-3.5px) rotate(-45deg); }
.mobile-sheet {
  position: absolute;
  top: 100%; left: 0; right: 0;
  background: var(--paper-2);
  border-bottom: 1px solid var(--line);
  padding: 10px var(--pad) 22px;
  display: flex;
  flex-direction: column;
  animation: sheet 0.4s var(--ease);
}
.mobile-sheet a { padding: 13px 0; border-bottom: 1px solid var(--line); font-size: 18px; font-family: var(--serif); }
@keyframes sheet { from { opacity: 0; transform: translateY(-8px); } }

.hero {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: clamp(120px, 17vh, 200px) var(--pad) clamp(50px, 8vh, 100px);
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: clamp(30px, 5vw, 76px);
  align-items: center;
}
.hero h1 { font-size: clamp(38px, 8.4vw, 96px); line-height: 1.04; letter-spacing: -0.03em; }
.hero h1 em { color: var(--cinnabar); position: relative; }
.hero h1 em::after {
  content: "";
  position: absolute;
  left: 2%; right: -2%; bottom: 0.06em;
  height: 0.08em;
  background: currentColor;
  opacity: 0.28;
  transform: scaleX(0);
  transform-origin: left;
  animation: sweep 1s var(--ease) 0.9s forwards;
}
@keyframes sweep { to { transform: scaleX(1); } }
.lede { font-size: clamp(16px, 1.35vw, 19px); color: var(--ink-2); margin: 30px 0 0; max-width: 30em; }
.hero-stage { position: relative; }
.frame-wrap { position: relative; will-change: transform; }
.ph-frame { transform: rotate(-2deg); }
.scroll-hint {
  display: flex;
  align-items: center;
  gap: 12px;
  justify-content: center;
  margin-top: 40px;
  font-size: 11px;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.scroll-hint i { width: 1px; height: 34px; background: linear-gradient(var(--ink-3), transparent); position: relative; overflow: hidden; }
.scroll-hint i::after {
  content: "";
  position: absolute; top: 0; left: 0;
  width: 100%; height: 40%;
  background: var(--cinnabar);
  animation: drop 1.9s var(--ease) infinite;
}
@keyframes drop { 0% { transform: translateY(-100%); } 60%, 100% { transform: translateY(250%); } }

.marquee {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 22px 0;
  overflow: hidden;
  background: var(--paper-2);
}
.marquee-track { display: flex; gap: 46px; width: max-content; animation: scrollx 38s linear infinite; }
.marquee:hover .marquee-track { animation-play-state: paused; }
.marquee-track span {
  font-family: var(--serif);
  font-size: clamp(18px, 2vw, 28px);
  color: var(--ink-3);
  display: inline-flex;
  align-items: center;
  gap: 46px;
  white-space: nowrap;
}
.marquee-track span::after { content: "·"; color: var(--cinnabar); }
@keyframes scrollx { to { transform: translateX(-50%); } }

.section { max-width: var(--maxw); margin: 0 auto; padding: clamp(74px, 11vh, 150px) var(--pad); }
.section-head { max-width: 720px; margin-bottom: clamp(40px, 6vw, 76px); }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.section-head h2 { font-size: clamp(32px, 4.6vw, 60px); line-height: 1.08; letter-spacing: -0.02em; }
.section-sub { font-size: clamp(15px, 1.3vw, 18px); color: var(--ink-2); margin: 22px 0 0; max-width: 36em; }
.section-head.center .section-sub { margin-left: auto; margin-right: auto; }

.mantra { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; border-top: 1px solid var(--line); padding-top: 42px; }
.mantra-item .idx { font-family: var(--display); font-size: 15px; color: var(--cinnabar); }
.mantra-item h3 { font-size: clamp(21px, 1.9vw, 27px); margin: 16px 0 12px; }
.mantra-item p { color: var(--ink-2); margin: 0; font-size: 15px; }
.mantra-item { position: relative; padding-top: 10px; }
.mantra-item::before {
  content: "";
  position: absolute;
  top: -42px; left: 0;
  width: 0; height: 1.5px;
  background: var(--cinnabar);
  transition: width 0.8s var(--ease);
}
.mantra-item.in::before { width: 46px; }

.scene-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.scene-item { transition: transform 0.5s var(--ease); }
.scene-item:hover { transform: translateY(-6px); }
.scene-item:nth-child(even) { margin-top: 38px; }
.scene-item figcaption { font-family: var(--serif); font-size: 18px; margin-top: 14px; text-align: center; }

.app-stage {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 300px));
  gap: clamp(24px, 5vw, 64px);
  justify-content: center;
}
.ph-phone figcaption { margin-top: 16px; font-size: 14px; color: var(--ink-2); text-align: center; }

.closing { background: var(--ink); color: var(--paper-2); padding: clamp(90px, 15vh, 200px) var(--pad); position: relative; overflow: hidden; }
.closing::before {
  content: "墨";
  position: absolute;
  right: -2%;
  top: -14%;
  font-family: var(--serif);
  font-size: 420px;
  color: rgba(255, 253, 248, 0.04);
  line-height: 1;
  pointer-events: none;
}
.closing-inner { max-width: var(--maxw); margin: 0 auto; position: relative; }
.closing h2 { font-size: clamp(36px, 6vw, 82px); line-height: 1.04; letter-spacing: -0.02em; }
.closing p { color: rgba(255, 253, 248, 0.6); margin: 30px 0 0; font-size: 13px; letter-spacing: 0.24em; text-transform: uppercase; }

.footer { background: var(--paper-2); border-top: 1px solid var(--line); padding: clamp(46px, 6vw, 70px) var(--pad) 34px; }
.footer-top { max-width: var(--maxw); margin: 0 auto; display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 16px; }
.footer-line { color: var(--ink-3); font-size: 13px; margin: 0; }
.footer-bottom {
  max-width: var(--maxw);
  margin: 40px auto 0;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 14px;
  font-size: 12px;
  color: var(--ink-3);
}

.ph { margin: 0; }
.ph-box {
  position: relative;
  aspect-ratio: var(--ratio, 4 / 3);
  width: 100%;
  border-radius: 16px;
  border: 1px dashed var(--line-strong);
  background:
    linear-gradient(135deg, rgba(37, 36, 33, 0.025) 25%, transparent 25%) 0 0 / 18px 18px,
    linear-gradient(-135deg, rgba(37, 36, 33, 0.025) 25%, transparent 25%) 0 0 / 18px 18px,
    var(--paper-2);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: clamp(16px, 3vw, 34px);
  text-align: center;
  overflow: hidden;
  transition: border-color 0.4s var(--ease);
}
.ph-box::before { content: "＋"; font-size: 22px; color: var(--cinnabar); line-height: 1; order: -1; opacity: 0.6; }
.ph:hover .ph-box { border-color: var(--cinnabar); }
.ph-tag {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--cinnabar);
  background: rgba(181, 38, 39, 0.07);
  border-radius: 100px;
  padding: 4px 12px;
}
.ph-desc { font-size: 13px; color: var(--ink-3); margin: 0; max-width: 34em; line-height: 1.6; }
.ph-frame .ph-box { border-style: solid; border-color: var(--line); box-shadow: 0 40px 80px -40px rgba(37, 36, 33, 0.45); }
.ph-phone .ph-box { border-radius: 30px; }

[data-reveal] {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.9s var(--ease), transform 0.9s var(--ease);
  transition-delay: calc(var(--i, 0) * 90ms);
}
[data-reveal].in { opacity: 1; transform: none; }

@media (max-width: 1024px) {
  .mantra { grid-template-columns: 1fr; gap: 34px; }
  .scene-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .scene-item:nth-child(even) { margin-top: 0; }
}

@media (max-width: 760px) {
  .nav-links { display: none; }
  .menu-btn { display: block; }
  .hero { grid-template-columns: 1fr; padding-top: 116px; }
  .hero-copy { order: 1; }
  .hero-stage { order: 2; margin-top: 8px; }
  .scroll-hint { display: none; }
  .scene-grid { grid-template-columns: 1fr; }
  .app-stage { grid-template-columns: 1fr; }
  .ph-phone { max-width: 320px; margin: 0 auto; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
  [data-reveal] { opacity: 1; transform: none; }
}