:root {
  color-scheme: light dark;
  --ink: #101418;
  --muted: #66707a;
  --line: rgba(16, 20, 24, 0.12);
  --paper: #f4f6f7;
  --white: #ffffff;
  --dark: #0b0e10;
  --dark-2: #15191d;
  --dark-line: rgba(255, 255, 255, 0.18);
  --blue: #7ba7df;
  --blue-ink: #1b3d61;
  --metal: #b7aa94;
  --shadow: 0 28px 90px rgba(17, 24, 31, 0.16);
  --max: 1240px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 86px;
}

body {
  margin: 0;
  font-family:
    "Inter", "SF Pro Display", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  background: var(--paper);
  color: var(--ink);
  letter-spacing: 0;
  text-rendering: geometricPrecision;
}

a {
  color: inherit;
  text-decoration: none;
}

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

.topbar {
  position: fixed;
  inset: 0 0 auto;
  z-index: 20;
  height: 72px;
  padding: 0 clamp(20px, 4vw, 52px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: #fff;
  background: linear-gradient(180deg, rgba(7, 9, 11, 0.62), rgba(7, 9, 11, 0));
  transition: background 260ms ease, border-color 260ms ease;
}

.topbar.is-solid {
  background: rgba(11, 14, 16, 0.78);
  border-bottom: 1px solid var(--dark-line);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  gap: 10px;
  align-items: center;
  font-weight: 650;
  font-size: 17px;
  letter-spacing: 0.01em;
}

.brand-mark {
  width: 18px;
  height: 18px;
  border: 1px solid currentColor;
  display: inline-block;
  position: relative;
}

.brand-mark::after {
  content: "";
  position: absolute;
  inset: 4px;
  border-top: 1px solid currentColor;
  border-left: 1px solid currentColor;
}

.nav {
  display: flex;
  align-items: center;
  gap: clamp(18px, 3vw, 38px);
  font-size: 14px;
  color: rgba(255, 255, 255, 0.82);
}

.nav a {
  padding: 8px 0;
  position: relative;
}

.nav a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 1px;
  height: 1px;
  transform: scaleX(0);
  transform-origin: left;
  background: currentColor;
  transition: transform 180ms ease;
}

.nav a:hover::after {
  transform: scaleX(1);
}

.hero {
  position: relative;
  min-height: 92svh;
  overflow: hidden;
  display: grid;
  align-items: center;
}

.hero::after {
  content: "";
  position: absolute;
  left: clamp(20px, 4vw, 52px);
  right: clamp(20px, 4vw, 52px);
  bottom: 28px;
  height: 1px;
  background: linear-gradient(90deg, rgba(255, 255, 255, 0.56), rgba(255, 255, 255, 0.06));
  z-index: 2;
}

.hero-image,
.hero-shade {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.hero-image {
  object-fit: cover;
  object-position: center right;
  filter: saturate(0.86) contrast(1.04);
  transform: scale(1.012);
}

.hero-shade {
  background:
    linear-gradient(90deg, rgba(5, 7, 9, 0.9) 0%, rgba(5, 7, 9, 0.68) 38%, rgba(5, 7, 9, 0.1) 78%),
    linear-gradient(180deg, rgba(0, 0, 0, 0.12), rgba(0, 0, 0, 0.58));
}

.hero-inner {
  position: relative;
  z-index: 1;
  width: min(var(--max), calc(100% - 40px));
  margin: 0 auto;
  padding: 132px 0 96px;
  color: #fff;
}

.hero-meta {
  display: grid;
  grid-template-columns: repeat(4, max-content);
  gap: clamp(16px, 3vw, 36px);
  margin-bottom: clamp(28px, 5vw, 54px);
  color: rgba(255, 255, 255, 0.62);
  font-size: 12px;
  line-height: 1.4;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.hero-meta span {
  position: relative;
}

.hero-meta span + span::before {
  content: "";
  position: absolute;
  left: clamp(-18px, -1.5vw, -8px);
  top: 50%;
  width: 4px;
  height: 4px;
  border-radius: 999px;
  background: rgba(123, 167, 223, 0.86);
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 22px;
  font-size: clamp(68px, 11vw, 148px);
  line-height: 0.92;
  font-weight: 720;
  letter-spacing: -0.01em;
}

.hero-lede {
  margin-bottom: 22px;
  font-size: clamp(26px, 4vw, 48px);
  line-height: 1.16;
  font-weight: 360;
  color: rgba(255, 255, 255, 0.92);
}

.hero-copy {
  max-width: 690px;
  color: rgba(255, 255, 255, 0.78);
  font-size: clamp(17px, 1.7vw, 21px);
  line-height: 1.8;
}

.hero-actions,
.inline-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 0 19px;
  border-radius: 4px;
  font-size: 14px;
  font-weight: 620;
  border: 1px solid transparent;
  transition: transform 180ms ease, border-color 180ms ease, background 180ms ease, color 180ms ease, box-shadow 180ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button.primary {
  background: #fff;
  color: var(--ink);
  box-shadow: 0 18px 42px rgba(0, 0, 0, 0.16);
}

.button.ghost {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.38);
  background: rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(10px);
}

.button.ghost:hover {
  border-color: rgba(255, 255, 255, 0.7);
  background: rgba(255, 255, 255, 0.12);
}

.section-light,
.section-dark {
  padding: clamp(88px, 10vw, 144px) clamp(20px, 4vw, 52px);
}

.section-dark {
  background: var(--dark);
  color: #fff;
}

.section-light {
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(244, 246, 247, 0.96)),
    var(--paper);
}

.section-head,
.material-grid,
.os,
.entries,
.mike,
.next {
  max-width: var(--max);
  margin: 0 auto;
}

.section-head {
  display: grid;
  grid-template-columns: 0.34fr 1fr;
  gap: clamp(26px, 5vw, 64px);
  align-items: end;
  margin-bottom: clamp(46px, 6vw, 78px);
}

.section-head.compact {
  align-items: start;
}

.section-kicker {
  margin-bottom: 18px;
  font-size: 13px;
  color: #6d7883;
  font-weight: 720;
  letter-spacing: 0.03em;
}

.section-dark .section-kicker {
  color: rgba(255, 255, 255, 0.58);
}

h2 {
  margin-bottom: 0;
  font-size: clamp(34px, 4.8vw, 68px);
  line-height: 1.02;
  font-weight: 620;
  letter-spacing: -0.01em;
}

.material-grid {
  display: grid;
  grid-template-columns: 0.56fr 1.04fr;
  gap: clamp(36px, 7vw, 92px);
  align-items: start;
}

.material-copy p,
.os-copy p,
.mike-panel p,
.next-copy p {
  color: var(--muted);
  font-size: 17px;
  line-height: 1.95;
}

.material-copy {
  position: sticky;
  top: 108px;
}

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-top: 22px;
  font-size: 15px;
  font-weight: 650;
  color: var(--ink);
  border-bottom: 1px solid currentColor;
  padding-bottom: 5px;
  transition: color 180ms ease, gap 180ms ease;
}

.text-link::after {
  content: "";
  width: 18px;
  height: 1px;
  background: currentColor;
  display: inline-block;
}

.text-link:hover {
  color: var(--blue-ink);
  gap: 14px;
}

.material-media {
  grid-column: 2;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  grid-template-rows: 160px 160px;
  gap: 12px;
  margin-bottom: 12px;
}

.material-media span {
  display: block;
  background-image: linear-gradient(180deg, rgba(255, 255, 255, 0.04), rgba(16, 20, 24, 0.18)), url("./assets/youyouzhigou-hero-material-ai.png");
  background-size: 1420px auto;
  border: 1px solid rgba(16, 20, 24, 0.1);
  filter: saturate(0.85);
  min-width: 0;
}

.material-media span:nth-child(1) {
  grid-row: span 2;
  background-position: 58% 50%;
}

.material-media span:nth-child(2) {
  background-position: 78% 42%;
}

.material-media span:nth-child(3) {
  background-position: 44% 64%;
}

.proof-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  padding: 0;
  margin: 0;
  border: 0;
  background: transparent;
}

.proof-list li {
  background: #fff;
  min-height: 190px;
  padding: 30px;
  border: 1px solid rgba(16, 20, 24, 0.1);
  box-shadow: 0 18px 50px rgba(17, 24, 31, 0.06);
  transition: transform 180ms ease, border-color 180ms ease, box-shadow 180ms ease;
}

.proof-list li:hover {
  transform: translateY(-2px);
  border-color: rgba(27, 61, 97, 0.22);
  box-shadow: 0 24px 70px rgba(17, 24, 31, 0.1);
}

.proof-list span,
.entry-index {
  display: block;
  margin-bottom: 28px;
  color: #7d8b99;
  font-size: 12px;
  font-weight: 700;
}

.proof-list strong {
  display: block;
  font-size: 21px;
  margin-bottom: 14px;
}

.proof-list small {
  display: block;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.os {
  display: grid;
  grid-template-columns: 0.58fr 1fr;
  gap: clamp(42px, 8vw, 96px);
  align-items: center;
  min-height: 640px;
}

.os-copy p {
  color: rgba(255, 255, 255, 0.68);
}

.os-map {
  position: relative;
  width: 100%;
  min-width: 0;
  aspect-ratio: 16 / 9;
  min-height: 320px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background:
    radial-gradient(circle at 68% 28%, rgba(123, 167, 223, 0.18), transparent 32%),
    linear-gradient(120deg, rgba(255, 255, 255, 0.09), transparent 36%),
    linear-gradient(180deg, #1a1f23, #0f1214);
  overflow: hidden;
  box-shadow: 0 28px 90px rgba(0, 0, 0, 0.28);
}

.os-map::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, transparent 0 18%, rgba(255, 255, 255, 0.08) 18% 18.2%, transparent 18.2% 100%),
    linear-gradient(90deg, transparent 0 50%, rgba(255, 255, 255, 0.09) 50% 50.2%, transparent 50.2% 100%),
    linear-gradient(90deg, transparent 0 78%, rgba(255, 255, 255, 0.08) 78% 78.2%, transparent 78.2% 100%);
}

.os-lines {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  stroke: rgba(143, 180, 231, 0.52);
  stroke-width: 1;
  fill: none;
}

.os-node {
  position: absolute;
  z-index: 1;
  min-width: 112px;
  padding: 10px 13px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  background: rgba(14, 16, 16, 0.74);
  color: rgba(255, 255, 255, 0.86);
  font-size: 14px;
  text-align: center;
  border-radius: 3px;
  backdrop-filter: blur(10px);
}

.os-node.center {
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  min-width: 150px;
  min-height: 74px;
  display: grid;
  place-items: center;
  font-size: 26px;
  font-weight: 650;
  color: #fff;
  border-color: rgba(123, 167, 223, 0.62);
  box-shadow: 0 0 0 1px rgba(123, 167, 223, 0.1), 0 18px 44px rgba(0, 0, 0, 0.22);
}

.node-a { left: 16%; top: 18%; }
.node-b { right: 12%; top: 24%; }
.node-c { right: 14%; bottom: 18%; }
.node-d { left: 14%; bottom: 20%; }

.entry-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.entry-card {
  position: relative;
  min-height: 360px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: 32px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.9), #fff),
    #fff;
  border: 1px solid var(--line);
  border-radius: 4px;
  overflow: hidden;
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
}

.entry-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 5px;
  background: var(--entry-accent, var(--blue));
  opacity: 0.82;
}

.entry-card::after {
  content: "";
  width: 28px;
  height: 1px;
  background: currentColor;
  opacity: 0.55;
  position: absolute;
  right: 32px;
  bottom: 32px;
  transition: width 180ms ease, opacity 180ms ease;
}

.entry-card:hover::after {
  width: 42px;
  opacity: 0.9;
}

.entry-advisor { --entry-accent: #1b3d61; }
.entry-gallery { --entry-accent: #7b8b96; }
.entry-training { --entry-accent: #0f7a54; }
.entry-os { --entry-accent: #9c8b6e; }

.entry-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow);
  border-color: rgba(17, 19, 21, 0.24);
}

.entry-card h3 {
  font-size: 26px;
  line-height: 1.15;
  margin-bottom: 16px;
}

.entry-card p {
  min-height: 148px;
  margin-bottom: 28px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.8;
}

.entry-card small {
  color: #707985;
  font-size: 13px;
  line-height: 1.5;
}

.mike {
  padding-top: 0;
}

.mike-panel {
  display: grid;
  grid-template-columns: 0.72fr 1fr;
  gap: 46px;
  align-items: start;
  padding: clamp(42px, 7vw, 72px) 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.mike-panel .text-link {
  margin-top: 0;
  margin-right: 18px;
}

.next {
  display: grid;
  grid-template-columns: 0.9fr 1fr;
  gap: clamp(36px, 7vw, 80px);
  align-items: center;
  min-height: 420px;
}

.next-copy p {
  color: rgba(255, 255, 255, 0.66);
}

.next .button.ghost {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.42);
}

[data-reveal],
section > * {
  opacity: 1;
  transform: none;
  transition: opacity 420ms ease, transform 420ms ease;
}

.hero-image,
.hero-shade,
.hero::after,
section.is-visible > *,
[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }

  [data-reveal],
  section > * {
    opacity: 1 !important;
    transform: none !important;
  }
}

@media (max-width: 900px) {
  .topbar {
    height: 64px;
  }

  .nav {
    display: none;
  }

  .hero {
    min-height: 90svh;
  }

  .hero-inner {
    width: min(100% - 32px, var(--max));
    padding: 104px 0 58px;
  }

  .hero-meta {
    grid-template-columns: 1fr 1fr;
    gap: 10px 18px;
    margin-bottom: 26px;
    font-size: 11px;
  }

  .hero-meta span + span::before {
    display: none;
  }

  .hero-shade {
    background:
      linear-gradient(90deg, rgba(6, 7, 8, 0.9), rgba(6, 7, 8, 0.55)),
      linear-gradient(180deg, rgba(0, 0, 0, 0.08), rgba(0, 0, 0, 0.58));
  }

  .section-head,
  .material-grid,
  .os,
  .mike-panel,
  .next {
    grid-template-columns: 1fr;
  }

  .section-head {
    gap: 16px;
  }

  .entry-grid,
  .proof-list {
    grid-template-columns: 1fr;
  }

  .material-copy {
    position: static;
  }

  .material-media {
    grid-column: auto;
    grid-template-columns: 1fr;
    grid-template-rows: 180px 120px;
  }

  .material-media span:nth-child(1) {
    grid-row: auto;
  }

  .material-media span:nth-child(3) {
    display: none;
  }

  .entry-grid {
    gap: 12px;
  }

  .os {
    min-height: unset;
  }

  .os-map {
    aspect-ratio: auto;
    min-height: 0;
    height: 320px;
  }

  .entry-card {
    min-height: 260px;
  }

  .entry-card p {
    min-height: auto;
  }
}

@media (min-width: 901px) and (max-width: 1180px) {
  .entry-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .entry-card p {
    min-height: 96px;
  }
}

@media (max-width: 520px) {
  .hero-actions,
  .inline-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .button {
    width: 100%;
  }

  .section-light,
  .section-dark {
    padding-left: 16px;
    padding-right: 16px;
  }

  .proof-list li,
  .entry-card {
    padding: 24px;
  }

  .mike-panel {
    padding: 34px 0;
  }

  h1 {
    font-size: clamp(58px, 18vw, 84px);
  }

  .hero-copy {
    font-size: 16px;
    line-height: 1.76;
  }

  .entry-card::after {
    right: 24px;
    bottom: 24px;
  }
}