:root {
  color-scheme: light;
  --bg: #f4f6f8;
  --surface: #ffffff;
  --surface-soft: #f8fafc;
  --ink: #172033;
  --muted: #667085;
  --line: #d9e0ea;
  --line-soft: #e9edf3;
  --blue: #2563eb;
  --blue-dark: #1d4ed8;
  --green: #027a48;
  --amber: #b54708;
  --violet: #6d4aff;
  --shadow: 0 18px 50px rgba(16, 24, 40, 0.12);
  --font: "Microsoft YaHei", "PingFang SC", "Segoe UI", Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background: var(--bg);
  font-family: var(--font);
}

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

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 24px;
  min-height: 72px;
  padding: 0 clamp(18px, 4vw, 56px);
  border-bottom: 1px solid rgba(217, 224, 234, 0.82);
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(18px);
}

.brand,
.top-actions,
.nav-links,
.hero-actions,
.cta-actions {
  display: flex;
  align-items: center;
}

.brand {
  gap: 12px;
  font-weight: 800;
}

.brand img {
  width: 36px;
  height: 36px;
  border-radius: 8px;
}

.nav-links {
  justify-content: center;
  gap: 22px;
  color: var(--muted);
  font-size: 14px;
}

.nav-links a {
  padding: 8px 2px;
}

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

.top-actions {
  gap: 10px;
}

.language-toggle,
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  border-radius: 6px;
  border: 1px solid var(--line);
  padding: 0 16px;
  font: inherit;
  font-weight: 800;
  cursor: pointer;
}

.language-toggle,
.button.ghost,
.button.secondary {
  color: var(--blue-dark);
  background: #fff;
}

.button.primary {
  color: #fff;
  border-color: var(--blue);
  background: var(--blue);
  box-shadow: 0 12px 28px rgba(37, 99, 235, 0.25);
}

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

.hero {
  position: relative;
  min-height: calc(100vh - 72px);
  display: flex;
  align-items: center;
  padding: clamp(72px, 9vw, 126px) clamp(22px, 7vw, 112px);
  overflow: hidden;
  background:
    linear-gradient(110deg, rgba(248, 250, 252, 0.98) 0%, rgba(248, 250, 252, 0.88) 48%, rgba(233, 237, 243, 0.78) 100%),
    repeating-linear-gradient(90deg, rgba(23, 32, 51, 0.05) 0 1px, transparent 1px 88px),
    repeating-linear-gradient(0deg, rgba(23, 32, 51, 0.04) 0 1px, transparent 1px 72px);
}

.hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: var(--line);
}

.hero-copy {
  position: relative;
  z-index: 4;
  width: min(760px, 100%);
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--blue-dark);
  font-size: 14px;
  font-weight: 900;
  letter-spacing: 0;
  text-transform: uppercase;
}

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

h1 {
  margin-bottom: 22px;
  max-width: 760px;
  font-size: clamp(46px, 6.8vw, 86px);
  line-height: 1.02;
  letter-spacing: 0;
}

.lead,
.section-heading p,
.feature-card p,
.step p {
  color: var(--muted);
  line-height: 1.75;
}

.lead {
  max-width: 660px;
  margin-bottom: 34px;
  font-size: clamp(17px, 2vw, 21px);
}

.hero-actions {
  gap: 12px;
  flex-wrap: wrap;
}

.hero-stage {
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
}

.feed-stack {
  position: absolute;
  right: clamp(32px, 7vw, 120px);
  top: 17%;
  width: min(470px, 38vw);
  display: grid;
  gap: 18px;
  transform: rotate(-2deg);
}

.feed-card,
.radar-panel,
.video-shell,
.feature-card,
.step,
.portal-card {
  border: 1px solid var(--line-soft);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.92);
  box-shadow: var(--shadow);
}

.feed-card {
  padding: 22px;
  min-height: 126px;
  transform: translateX(42px);
  opacity: 0.78;
  animation: driftCard 8s ease-in-out infinite;
}

.feed-card.active {
  transform: translateX(0);
  opacity: 1;
}

.feed-card:nth-child(2) {
  animation-delay: -2s;
}

.feed-card:nth-child(3) {
  animation-delay: -4s;
}

.feed-label {
  display: inline-flex;
  margin-bottom: 12px;
  color: var(--blue-dark);
  font-size: 12px;
  font-weight: 900;
}

.feed-card strong {
  display: block;
  font-size: clamp(22px, 2.5vw, 32px);
}

.feed-card small {
  display: block;
  margin-top: 8px;
  color: var(--muted);
}

.scan-beam {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 58%;
  width: 2px;
  background: linear-gradient(180deg, transparent, rgba(37, 99, 235, 0.88), transparent);
  box-shadow: 0 0 34px rgba(37, 99, 235, 0.5);
  animation: scanBeam 4.8s ease-in-out infinite;
}

.radar-panel {
  position: absolute;
  right: clamp(32px, 9vw, 150px);
  bottom: 12%;
  width: min(420px, 35vw);
  padding: 18px;
  background: rgba(23, 32, 51, 0.93);
  color: #fff;
}

.radar-header {
  display: flex;
  gap: 8px;
  margin-bottom: 18px;
}

.radar-header span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #fff;
  opacity: 0.55;
}

.radar-grid {
  position: relative;
  height: 180px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  background:
    repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.08) 0 1px, transparent 1px 46px),
    repeating-linear-gradient(0deg, rgba(255, 255, 255, 0.08) 0 1px, transparent 1px 46px);
  overflow: hidden;
}

.signal {
  position: absolute;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 0 8px rgba(2, 122, 72, 0.2);
  animation: signalPulse 2.4s ease-in-out infinite;
}

.s1 { left: 22%; top: 36%; }
.s2 { left: 62%; top: 28%; animation-delay: -0.8s; }
.s3 { left: 48%; top: 66%; animation-delay: -1.6s; }

.confidence-ring {
  position: absolute;
  right: 28px;
  bottom: 28px;
  display: grid;
  place-items: center;
  width: 82px;
  height: 82px;
  border-radius: 50%;
  border: 8px solid rgba(2, 122, 72, 0.95);
  background: #fff;
  color: var(--ink);
  font-weight: 900;
  font-variant-numeric: tabular-nums;
}

.band,
.demo-section,
.feature-section,
.workflow-section,
.cta-section,
.footer {
  width: min(1180px, calc(100% - 44px));
  margin: 0 auto;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin-top: -42px;
  position: relative;
  z-index: 6;
  border: 1px solid var(--line-soft);
  border-radius: 8px;
  overflow: hidden;
  background: var(--line-soft);
  box-shadow: var(--shadow);
}

.metrics div {
  padding: 26px;
  background: #fff;
}

.metrics strong {
  display: block;
  color: var(--blue-dark);
  font-size: clamp(30px, 4vw, 48px);
  font-variant-numeric: tabular-nums;
}

.metrics span {
  color: var(--muted);
  font-weight: 700;
}

.demo-section,
.feature-section,
.workflow-section,
.cta-section {
  padding: clamp(70px, 8vw, 108px) 0 0;
}

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

.section-heading h2,
.cta-section h2 {
  margin-bottom: 14px;
  font-size: clamp(32px, 4.6vw, 58px);
  line-height: 1.08;
}

.video-shell {
  padding: 14px;
  background: #111827;
}

.video-shell video {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: 6px;
  background: #0f172a;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.feature-card {
  padding: 24px;
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.feature-card:hover,
.portal-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 24px 62px rgba(16, 24, 40, 0.16);
}

.feature-card img {
  display: block;
  width: 100%;
  height: 210px;
  margin-bottom: 20px;
  object-fit: contain;
  border: 1px solid var(--line-soft);
  border-radius: 8px;
  background: var(--surface-soft);
}

.feature-card h3 {
  margin-bottom: 10px;
  font-size: 22px;
}

.workflow {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.step {
  min-height: 230px;
  padding: 24px;
  position: relative;
  overflow: hidden;
}

.step::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 4px;
  background: var(--line);
}

.step.active::after,
.step:hover::after {
  background: linear-gradient(90deg, var(--blue), var(--green));
}

.step span {
  color: var(--amber);
  font-weight: 900;
  font-variant-numeric: tabular-nums;
}

.step strong {
  display: block;
  margin: 18px 0 10px;
  font-size: 22px;
}

.cta-section {
  padding-bottom: clamp(70px, 8vw, 108px);
}

.cta-actions {
  gap: 16px;
  flex-wrap: wrap;
}

.portal-card {
  flex: 1 1 320px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-height: 126px;
  padding: 28px;
  background:
    linear-gradient(135deg, rgba(37, 99, 235, 0.09), transparent 44%),
    #fff;
}

.portal-card.admin {
  background:
    linear-gradient(135deg, rgba(181, 71, 8, 0.1), transparent 44%),
    #fff;
}

.portal-card span {
  font-size: 24px;
  font-weight: 900;
}

.portal-card small {
  color: var(--muted);
  font-size: 15px;
}

.footer {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 26px 0 44px;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 620ms ease, transform 620ms ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@keyframes scanBeam {
  0%, 100% { transform: translateX(-130px); opacity: 0.3; }
  48% { transform: translateX(180px); opacity: 1; }
}

@keyframes driftCard {
  0%, 100% { transform: translateX(26px); }
  50% { transform: translateX(0); }
}

@keyframes signalPulse {
  0%, 100% { transform: scale(0.92); opacity: 0.75; }
  50% { transform: scale(1.18); opacity: 1; }
}

@media (max-width: 980px) {
  .topbar {
    grid-template-columns: 1fr auto;
  }

  .nav-links {
    display: none;
  }

  .hero {
    min-height: auto;
    padding-top: 72px;
    padding-bottom: 320px;
  }

  .feed-stack {
    top: auto;
    left: 22px;
    right: 22px;
    bottom: 38px;
    width: auto;
  }

  .radar-panel,
  .scan-beam {
    display: none;
  }

  .metrics,
  .feature-grid,
  .workflow {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  .topbar {
    min-height: 64px;
    padding-inline: 14px;
  }

  .brand span,
  .button.ghost {
    display: none;
  }

  .hero {
    padding-inline: 18px;
  }

  .feed-card {
    min-height: 100px;
    padding: 18px;
  }

  .footer {
    flex-direction: column;
  }
}