/* ============================================================
   SlumberDoze — website design system
   Quiet luxury: near-black ink, warm paper type, matte gold,
   serif display against a restrained sans. Motion is slow.
   ============================================================ */

:root {
  --ink: #05060a;
  --ink-raise: #0a0c12;
  --ink-soft: #10131c;
  --paper: #f3efe6;
  --paper-dim: rgba(243, 239, 230, 0.58);
  --paper-faint: rgba(243, 239, 230, 0.42);
  --line: rgba(243, 239, 230, 0.1);
  --line-strong: rgba(243, 239, 230, 0.2);
  --gold: #c2a05f;
  --gold-dim: rgba(194, 160, 95, 0.55);
  --gold-faint: rgba(194, 160, 95, 0.14);
  --cool: #6fa6d8;

  --serif: ui-serif, "New York", "Iowan Old Style", "Palatino Linotype", Palatino,
    Georgia, "Songti SC", "Noto Serif CJK SC", "Hiragino Mincho ProN", "Yu Mincho", serif;
  --sans: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue",
    "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC", "Microsoft YaHei", sans-serif;

  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --gutter: clamp(20px, 5vw, 72px);
  --measure: 1180px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; overflow-x: clip; }

body {
  margin: 0;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

/* Ambient atmosphere: two very slow light fields + film grain */
body::before {
  content: "";
  position: fixed;
  inset: -20vh -10vw;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(closest-side at 22% 8%, rgba(111, 166, 216, 0.16), transparent 100%),
    radial-gradient(closest-side at 82% 24%, rgba(194, 160, 95, 0.1), transparent 100%),
    radial-gradient(closest-side at 60% 92%, rgba(96, 84, 150, 0.14), transparent 100%);
  filter: blur(20px);
  animation: drift 42s var(--ease) infinite alternate;
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
}

@keyframes drift {
  from { transform: translate3d(-1.5%, -1%, 0) scale(1); }
  to { transform: translate3d(2%, 2.5%, 0) scale(1.08); }
}

main, header, footer { position: relative; z-index: 2; }

a { color: inherit; }

img { display: block; max-width: 100%; height: auto; }

/* 避免段末孤字/短尾行 */
p, li, blockquote { text-wrap: pretty; }

::selection { background: var(--gold); color: var(--ink); }

/* ---------------------------------------------------------- nav */

.nav {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 28px;
  padding: 18px var(--gutter);
  background: rgba(5, 6, 10, 0.66);
  backdrop-filter: saturate(140%) blur(18px);
  -webkit-backdrop-filter: saturate(140%) blur(18px);
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
  margin-right: auto;
}

.brand img {
  width: 26px;
  height: 26px;
  border-radius: 7px;
  box-shadow: 0 0 0 1px rgba(243, 239, 230, 0.14);
}

.brand span {
  font-size: 11px;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--paper);
}

.nav-links {
  display: flex;
  gap: 26px;
  align-items: center;
}

.nav-links a {
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--paper-dim);
  text-decoration: none;
  transition: color 0.4s var(--ease);
}

.nav-links a:hover { color: var(--paper); }

.nav.is-compact { padding-top: 11px; padding-bottom: 11px; }

/* language switcher */
.lang { position: relative; }

.lang > summary {
  list-style: none;
  cursor: pointer;
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--paper-dim);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 7px 13px;
  transition: border-color 0.4s var(--ease), color 0.4s var(--ease);
}

.lang > summary::-webkit-details-marker { display: none; }
.lang > summary:hover { border-color: var(--line-strong); color: var(--paper); }

.lang-panel {
  position: absolute;
  right: 0;
  top: calc(100% + 10px);
  min-width: 168px;
  padding: 8px;
  background: rgba(10, 12, 18, 0.94);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.55);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

.lang-panel a {
  display: block;
  padding: 9px 12px;
  font-size: 13px;
  color: var(--paper-dim);
  text-decoration: none;
  border-radius: 9px;
  transition: background 0.3s var(--ease), color 0.3s var(--ease);
}

.lang-panel a:hover { background: rgba(243, 239, 230, 0.06); color: var(--paper); }
.lang-panel a[aria-current="true"] { color: var(--gold); }

/* ---------------------------------------------------------- buttons */

.btn {
  --btn-bg: var(--paper);
  --btn-fg: #0a0b10;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 15px 30px;
  border-radius: 999px;
  background: var(--btn-bg);
  color: var(--btn-fg);
  font-size: 14px;
  letter-spacing: 0.02em;
  text-decoration: none;
  border: 1px solid transparent;
  transition: transform 0.5s var(--ease), box-shadow 0.5s var(--ease), background 0.5s var(--ease);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}

.btn:hover { transform: translateY(-2px); box-shadow: 0 16px 40px rgba(0, 0, 0, 0.45); }

.btn-ghost {
  --btn-bg: transparent;
  --btn-fg: var(--paper);
  border-color: var(--line-strong);
  box-shadow: none;
  font-weight: 400;
}

.btn-ghost:hover { background: rgba(243, 239, 230, 0.04); border-color: var(--gold-dim); box-shadow: none; }

.btn-small {
  padding: 10px 20px;
  font-size: 12px;
  letter-spacing: 0.06em;
  box-shadow: none;
}

.btn-gold {
  --btn-bg: transparent;
  --btn-fg: var(--gold);
  border-color: var(--gold-dim);
  box-shadow: none;
}

.btn-gold:hover { background: var(--gold-faint); box-shadow: none; }

/* ---------------------------------------------------------- layout */

.wrap {
  width: 100%;
  max-width: var(--measure);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.kicker {
  margin: 0 0 22px;
  font-size: 10.5px;
  letter-spacing: 0.34em;
  text-transform: uppercase;
  color: var(--gold);
}

.lede {
  font-size: clamp(16.5px, 1.35vw, 19px);
  line-height: 1.62;
  color: var(--paper-dim);
  max-width: 46ch;
}

/* ---------------------------------------------------------- hero */

.hero {
  min-height: calc(100svh - 67px);
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  gap: clamp(32px, 5vw, 88px);
  align-items: center;
  max-width: var(--measure);
  margin: 0 auto;
  padding: clamp(56px, 9vh, 116px) var(--gutter) clamp(64px, 10vh, 132px);
}

.hero h1 {
  margin: 0 0 26px;
  text-wrap: balance;
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(46px, 7.1vw, 104px);
  line-height: 0.97;
  letter-spacing: -0.028em;
}

.hero h1 em {
  font-style: italic;
  color: var(--gold);
}

:lang(ja) .hero h1,
:lang(ko) .hero h1 {
  font-size: clamp(34px, 5.2vw, 76px);
  word-break: keep-all;
  line-height: 1.06;
}

:lang(zh) .hero h1 {
  font-size: clamp(44px, 6.4vw, 92px);
  line-height: 1.04;
}

.hero .actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 36px;
}

.hero .note {
  margin: 22px 0 0;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--paper-faint);
}

.hero-media {
  position: relative;
  display: flex;
  justify-content: center;
}

.device {
  position: relative;
  width: min(100%, 330px);
  border-radius: 42px;
  padding: 8px;
  background: linear-gradient(160deg, rgba(243, 239, 230, 0.22), rgba(243, 239, 230, 0.04) 42%, rgba(243, 239, 230, 0.1));
  box-shadow:
    0 60px 120px -30px rgba(0, 0, 0, 0.9),
    0 0 0 1px rgba(0, 0, 0, 0.6),
    inset 0 1px 0 rgba(255, 255, 255, 0.24);
  transition: transform 0.9s var(--ease);
}

.device img {
  width: 100%;
  height: auto;
  border-radius: 35px;
  background: #000;
}

.device::after {
  content: "";
  position: absolute;
  inset: 8px;
  border-radius: 35px;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.09);
  pointer-events: none;
}

.hero-media .halo {
  position: absolute;
  inset: -14% -22%;
  z-index: -1;
  background: radial-gradient(closest-side, rgba(111, 166, 216, 0.22), transparent 72%);
  filter: blur(30px);
}

/* ---------------------------------------------------------- chapters */

.chapter {
  padding: clamp(52px, 8vh, 104px) 0;
  border-top: 1px solid var(--line);
}

.chapter-head {
  display: grid;
  grid-template-columns: 84px minmax(0, 1fr) minmax(0, 0.85fr);
  gap: clamp(20px, 4vw, 60px);
  align-items: end;
}

.chapter-head .num {
  font-family: var(--serif);
  font-size: 13px;
  letter-spacing: 0.18em;
  color: var(--gold);
  padding-bottom: 12px;
}

.chapter-head h2 {
  margin: 0;
  text-wrap: balance;
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(30px, 3.5vw, 54px);
  line-height: 1.06;
  letter-spacing: -0.02em;
}

.chapter-head .side {
  color: var(--paper-dim);
  font-size: 15px;
  line-height: 1.7;
  padding-bottom: 6px;
}

.chapter-body {
  display: grid;
  grid-template-columns: 84px minmax(0, 1fr);
  gap: clamp(20px, 4vw, 60px);
  margin-top: clamp(30px, 5vh, 56px);
}

.chapter-body > .content { max-width: 62ch; }

/* editorial list */
.registry {
  margin: 34px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.registry li {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 18px;
  align-items: baseline;
  padding: 17px 0;
  border-bottom: 1px solid var(--line);
}

.registry .t {
  font-size: 15.5px;
  letter-spacing: 0.01em;
}

.registry .d {
  font-size: 12.5px;
  color: var(--paper-faint);
  letter-spacing: 0.04em;
  text-align: right;
}

/* ---------------------------------------------------------- split feature */

.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(24px, 4.5vw, 72px);
  align-items: center;
  padding: clamp(52px, 8vh, 104px) var(--gutter);
  border-top: 1px solid var(--line);
}

.split.flip { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
.split.flip .split-copy { order: 2; }
.split.flip .split-media { order: 1; }

.split-copy h2 {
  margin: 0 0 20px;
  text-wrap: balance;
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(28px, 3.2vw, 46px);
  line-height: 1.1;
  letter-spacing: -0.018em;
}

.split-copy p {
  margin: 0 0 14px;
  color: var(--paper-dim);
  max-width: 44ch;
}

.split-media { display: flex; justify-content: center; }
.split-media .device { width: min(100%, 300px); }

/* stat row */
.stats {
  display: flex;
  gap: clamp(20px, 4vw, 56px);
  margin: 32px 0 0;
  padding: 0;
  list-style: none;
}

.stats li { display: grid; gap: 4px; }

.stats b {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 26px;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.stats span {
  font-size: 10.5px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: rgba(243, 239, 230, 0.5);
}

/* ---------------------------------------------------------- privacy / pledge */

.pledge {
  padding: clamp(64px, 11vh, 132px) var(--gutter);
  border-top: 1px solid var(--line);
  text-align: center;
}

.pledge blockquote {
  margin: 0 auto;
  max-width: 22ch;
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(30px, 4.4vw, 64px);
  line-height: 1.1;
  letter-spacing: -0.022em;
}

.pledge blockquote em { font-style: italic; color: var(--gold); }

.pledge p {
  margin: 28px auto 0;
  max-width: 54ch;
  color: var(--paper-dim);
  font-size: 15px;
}

/* ---------------------------------------------------------- devices */

.devices {
  padding: clamp(52px, 8vh, 104px) var(--gutter) clamp(20px, 3vh, 40px);
  border-top: 1px solid var(--line);
}

.devices h2 {
  margin: 0;
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(30px, 3.5vw, 50px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  max-width: 26ch;
}

.devices .meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 26px;
  margin-top: 18px;
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--paper-faint);
}

.device-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin-top: 44px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: 20px;
  overflow: hidden;
}

.device-grid > div {
  background: var(--ink);
  padding: 30px 26px;
}

.device-grid h3 {
  margin: 0 0 8px;
  font-family: var(--serif);
  font-weight: 400;
  font-size: 19px;
  letter-spacing: -0.01em;
}

.device-grid p {
  margin: 0;
  font-size: 13.5px;
  color: var(--paper-faint);
  line-height: 1.65;
}

/* ---------------------------------------------------------- pro */

.pro {
  margin: clamp(28px, 5vh, 64px) 0 clamp(40px, 7vh, 84px);
  padding: clamp(34px, 6vw, 66px);
  border: 1px solid var(--gold-faint);
  border-radius: 24px;
  background:
    radial-gradient(120% 140% at 85% 0%, rgba(194, 160, 95, 0.12), transparent 62%),
    rgba(194, 160, 95, 0.03);
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) auto;
  gap: 32px;
  align-items: center;
}

.pro h2 {
  margin: 6px 0 12px;
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(26px, 3vw, 40px);
  line-height: 1.12;
  letter-spacing: -0.018em;
}

.pro p { margin: 0; color: var(--paper-dim); font-size: 14.5px; max-width: 52ch; }

/* ---------------------------------------------------------- footer */

.footer {
  border-top: 1px solid var(--line);
  padding: clamp(44px, 7vh, 76px) var(--gutter) 40px;
}

.footer-top {
  display: flex;
  flex-wrap: wrap;
  gap: 30px;
  justify-content: space-between;
  align-items: flex-start;
}

.footer-brand { display: flex; align-items: center; gap: 12px; }
.footer-brand img { width: 30px; height: 30px; border-radius: 8px; }
.footer-brand span { font-size: 11px; letter-spacing: 0.26em; text-transform: uppercase; }

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 22px;
  font-size: 12.5px;
  color: var(--paper-dim);
}

.footer-links a { text-decoration: none; transition: color 0.4s var(--ease); }
.footer-links a:hover { color: var(--paper); }

.footer-note {
  margin: 34px 0 0;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  font-size: 11.5px;
  line-height: 1.8;
  color: var(--paper-faint);
  max-width: 78ch;
}

/* ---------------------------------------------------------- documents */

.doc {
  max-width: 720px;
  margin: 0 auto;
  padding: clamp(48px, 9vh, 96px) var(--gutter) clamp(64px, 10vh, 120px);
}

.doc h1 {
  margin: 8px 0 10px;
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(32px, 4.4vw, 54px);
  line-height: 1.06;
  letter-spacing: -0.022em;
}

.doc .stamp {
  margin: 0 0 40px;
  font-size: 11.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--paper-faint);
}

.doc h2 {
  margin: 46px 0 10px;
  font-family: var(--serif);
  font-weight: 400;
  font-size: 21px;
  letter-spacing: -0.005em;
}

.doc p {
  margin: 0 0 18px;
  color: rgba(243, 239, 230, 0.68);
  font-size: 16px;
  line-height: 1.8;
}

.doc a { color: var(--gold); text-decoration: none; border-bottom: 1px solid var(--gold-faint); }
.doc a:hover { border-color: var(--gold); }

.doc .back {
  display: inline-block;
  margin-top: 48px;
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--paper-faint);
  text-decoration: none;
  border: 0;
}

.doc .back:hover { color: var(--paper); }

/* FAQ */
.faq { border-top: 1px solid var(--line); margin-top: 12px; }

.faq details { border-bottom: 1px solid var(--line); }

.faq summary {
  cursor: pointer;
  list-style: none;
  padding: 20px 30px 20px 0;
  position: relative;
  font-size: 15.5px;
  color: var(--paper);
  transition: color 0.4s var(--ease);
}

.faq summary::-webkit-details-marker { display: none; }

.faq summary::after {
  content: "+";
  position: absolute;
  right: 2px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--gold);
  font-family: var(--serif);
  font-size: 18px;
  transition: transform 0.4s var(--ease);
}

.faq details[open] summary::after { transform: translateY(-50%) rotate(45deg); }

.faq .answer {
  padding: 0 0 22px;
  color: var(--paper-dim);
  font-size: 14.5px;
  max-width: 68ch;
}

/* contact card inside docs */
.contact {
  margin: 26px 0 8px;
  padding: 26px 28px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: rgba(243, 239, 230, 0.02);
}

.contact h2 { margin: 0 0 8px; font-size: 17px; font-family: var(--sans); letter-spacing: 0; }

/* ---------------------------------------------------------- motion */

.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 1s var(--ease), transform 1s var(--ease);
  will-change: opacity, transform;
}

.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  body::before { animation: none; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .device { transition: none; }
}

/* ---------------------------------------------------------- responsive */

@media (max-width: 1000px) {
  .chapter-head { grid-template-columns: minmax(0, 1fr); gap: 10px 20px; }
  .chapter-head .num { padding-bottom: 0; }
  .chapter-head .side { grid-column: 1; padding-bottom: 0; margin-top: 6px; }
  .chapter-body { grid-template-columns: minmax(0, 1fr); }
  .chapter-body > span { display: none; }
  .hero { grid-template-columns: 1fr; padding-top: 40px; min-height: 0; gap: 40px; }
  .hero-media { order: 0; }
  .hero .device { width: min(100%, 300px); }
  .split, .split.flip { grid-template-columns: 1fr; }
  .split.flip .split-copy, .split.flip .split-media { order: initial; }
  .split-media { margin-top: 8px; }
  .device-grid { grid-template-columns: 1fr; }
  .pro { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
  .nav { gap: 12px; padding: 13px var(--gutter); }
  .nav-links { display: none; }
  .nav > .btn { display: none; }
  .brand { padding: 9px 10px; margin: -9px auto -9px -10px; }
  .brand span { display: none; }
  .hero-media .halo { inset: -8%; }
  .hero h1 { font-size: clamp(40px, 12vw, 62px); }
  .registry li { grid-template-columns: minmax(0, 1fr); }
  .registry .d { display: none; }
  .stats { flex-wrap: wrap; gap: 22px 32px; }
  .footer-top { flex-direction: column; }
}