:root {
  --bg-paper: #f5f1e8;
  --bg-panel: rgba(255, 255, 255, 0.7);
  --bg-panel-strong: rgba(255, 255, 255, 0.86);
  --ink-900: #1f2a33;
  --ink-700: #45525b;
  --ink-500: #64727a;
  --line-soft: rgba(31, 42, 51, 0.12);
  --line-strong: rgba(31, 42, 51, 0.2);
  --accent-teal: #0d8a7c;
  --accent-gold: #b28a3f;
  --shadow-card: 0 18px 50px rgba(31, 42, 51, 0.08);
  --shadow-header: 0 8px 24px rgba(31, 42, 51, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink-900);
  font-family: "PingFang SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
  background:
    radial-gradient(circle at top left, rgba(13, 138, 124, 0.08), transparent 30%),
    radial-gradient(circle at top right, rgba(178, 138, 63, 0.12), transparent 26%),
    var(--bg-paper);
}

body.is-scrolled .site-header {
  box-shadow: var(--shadow-header);
  background: rgba(245, 241, 232, 0.92);
}

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

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

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

.shell {
  width: min(1120px, calc(100% - 48px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid rgba(31, 42, 51, 0.08);
  backdrop-filter: blur(18px);
  background: rgba(245, 241, 232, 0.78);
  transition: background 180ms ease, box-shadow 180ms ease;
}

.header-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 72px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.brand-mark {
  font-size: 1.05rem;
}

.header-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  color: var(--ink-700);
  font-size: 0.95rem;
}

.header-nav a:hover {
  color: var(--accent-teal);
}

.header-nav a:focus-visible {
  outline: 2px solid var(--accent-teal);
  outline-offset: 4px;
  color: var(--accent-teal);
}

.hero-section {
  padding: 72px 0 48px;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(280px, 0.9fr);
  gap: 28px;
  align-items: start;
}

.hero-copy h1,
.section-intro h2,
.value-card h3,
.info-card h3 {
  font-family: "Songti SC", "Source Han Serif SC", "Noto Serif CJK SC", serif;
}

.hero-copy h1 {
  margin-bottom: 8px;
  font-size: clamp(2.9rem, 7vw, 4.6rem);
  line-height: 1.02;
}

.hero-copy h2 {
  margin-bottom: 16px;
  font-size: clamp(1.25rem, 3vw, 1.9rem);
  font-weight: 600;
  color: var(--ink-700);
}

.hero-summary {
  max-width: 680px;
  margin-bottom: 28px;
  color: var(--ink-700);
  font-size: 1.06rem;
}

.eyebrow {
  margin-bottom: 18px;
  color: var(--accent-teal);
  font-size: 0.88rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-weight: 700;
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button:focus-visible {
  outline: 2px solid var(--accent-gold);
  outline-offset: 4px;
}

.button-primary {
  background: var(--ink-900);
  color: #ffffff;
  box-shadow: 0 10px 24px rgba(31, 42, 51, 0.18);
}

.button-secondary {
  border-color: rgba(31, 42, 51, 0.14);
  background: rgba(255, 255, 255, 0.6);
}

.hero-panel,
.info-card,
.value-card,
.demo-frame {
  border: 1px solid var(--line-soft);
  border-radius: 24px;
  background: var(--bg-panel-strong);
  box-shadow: var(--shadow-card);
}

.hero-panel {
  padding: 24px;
}

.panel-title {
  margin-bottom: 14px;
  font-size: 0.94rem;
  font-weight: 700;
  color: var(--ink-700);
}

.pill-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  padding: 0;
  margin: 0;
  list-style: none;
}

.pill-list li {
  padding: 8px 14px;
  border: 1px solid rgba(13, 138, 124, 0.18);
  border-radius: 999px;
  background: rgba(13, 138, 124, 0.08);
  color: var(--ink-700);
  font-size: 0.92rem;
}

.section-block {
  padding: 56px 0;
}

.section-accent {
  background: linear-gradient(180deg, rgba(13, 138, 124, 0.06), rgba(13, 138, 124, 0));
}

.section-dark {
  background:
    linear-gradient(180deg, rgba(31, 42, 51, 0.98), rgba(31, 42, 51, 0.95)),
    var(--ink-900);
  color: rgba(255, 255, 255, 0.92);
}

.section-dark .eyebrow,
.section-dark .value-list li::marker {
  color: #91d3cb;
}

.section-dark .section-intro p,
.section-dark .value-list {
  color: rgba(255, 255, 255, 0.8);
}

.section-intro {
  margin-bottom: 28px;
  max-width: 760px;
}

.section-intro h2 {
  margin-bottom: 12px;
  font-size: clamp(1.9rem, 4vw, 3rem);
  line-height: 1.12;
}

.section-intro p {
  color: var(--ink-700);
}

.card-grid {
  display: grid;
  gap: 20px;
}

.card-grid-three {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.card-grid-two {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.info-card,
.value-card {
  padding: 24px;
}

.info-card h3,
.value-card h3 {
  margin-bottom: 12px;
  font-size: 1.5rem;
}

.info-card p,
.value-list {
  color: var(--ink-700);
}

.summary-band {
  margin-top: 24px;
  padding: 18px 22px;
  border-left: 4px solid var(--accent-gold);
  border-radius: 16px;
  background: rgba(178, 138, 63, 0.1);
  color: var(--ink-900);
  font-size: 1.02rem;
  font-weight: 700;
}

.demo-frame {
  padding: 16px;
  background: rgba(255, 255, 255, 0.88);
}

.demo-video {
  width: 100%;
  border-radius: 16px;
  background: #0f1720;
}

.pill-list-centered {
  justify-content: center;
  margin-top: 18px;
}

.value-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.value-list {
  margin: 0;
  padding-left: 20px;
}

.value-list li + li {
  margin-top: 10px;
}

.site-footer {
  padding: 28px 0 42px;
  border-top: 1px solid rgba(31, 42, 51, 0.08);
}

.footer-layout {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  align-items: end;
}

.footer-title {
  margin-bottom: 8px;
  font-weight: 700;
}

.footer-note,
.footer-meta {
  color: var(--ink-500);
}

.js-ready [data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity 480ms ease,
    transform 480ms ease;
}

.js-ready [data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 900px) {
  .hero-grid,
  .card-grid-three,
  .card-grid-two,
  .value-grid,
  .footer-layout {
    grid-template-columns: 1fr;
    flex-direction: column;
  }

  .header-bar {
    align-items: flex-start;
    padding: 14px 0;
  }

  .header-nav {
    gap: 12px;
  }

  .shell {
    width: min(1120px, calc(100% - 32px));
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .js-ready [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .button,
  .site-header {
    transition: none;
  }
}