:root {
  color-scheme: light;
  --ink: #172033;
  --muted: #667085;
  --line: #d9e2ef;
  --panel: #ffffff;
  --bg: #f4f7fb;
  --blue: #2563eb;
  --green: #0f8f61;
  --red: #ce3f4a;
  --amber: #d97706;
  --teal: #0f766e;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--bg);
}

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

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 66px;
  padding: 0 48px;
  background: rgba(244, 247, 251, 0.92);
  border-bottom: 1px solid rgba(217, 226, 239, 0.9);
  backdrop-filter: blur(16px);
}

.brand,
.nav {
  display: flex;
  align-items: center;
  gap: 16px;
}

.brand {
  font-weight: 760;
}

.brand-mark {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  color: #fff;
  background: var(--ink);
  border-radius: 6px;
  font-size: 13px;
  letter-spacing: 0;
}

.nav a {
  color: var(--muted);
  font-size: 14px;
}

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

main {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(320px, 0.75fr);
  gap: 44px;
  align-items: center;
  min-height: calc(100vh - 66px);
  padding: 74px 0 58px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--blue);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

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

h1 {
  max-width: 780px;
  margin-bottom: 24px;
  font-size: clamp(48px, 7vw, 86px);
  line-height: 0.98;
  letter-spacing: 0;
}

.lead {
  max-width: 720px;
  color: var(--muted);
  font-size: 20px;
  line-height: 1.75;
}

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

.button {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  padding: 0 18px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
  color: var(--ink);
  font-weight: 760;
}

.button.primary {
  border-color: var(--blue);
  background: var(--blue);
  color: #fff;
}

.hero-metrics {
  display: grid;
  gap: 12px;
}

.hero-metrics div,
.stat-card,
.step,
.evidence-list div {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: 0 18px 50px rgba(23, 32, 51, 0.06);
}

.hero-metrics div {
  padding: 24px;
}

.hero-metrics span,
.stat-card span {
  display: block;
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 14px;
}

.hero-metrics strong {
  font-size: 30px;
  letter-spacing: 0;
}

.video-section,
.pipeline,
.evidence {
  padding: 58px 0;
}

.section-heading {
  display: grid;
  gap: 10px;
  max-width: 780px;
  margin-bottom: 28px;
}

.section-heading h2 {
  margin: 0;
  font-size: clamp(30px, 4vw, 52px);
  line-height: 1.08;
  letter-spacing: 0;
}

.section-heading p:last-child {
  margin: 0;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.7;
}

.case-video {
  display: block;
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #101828;
  box-shadow: 0 22px 70px rgba(23, 32, 51, 0.14);
}

.case-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  padding: 30px 0 58px;
}

.stat-card {
  padding: 24px;
  border-top-width: 5px;
}

.stat-card.trend {
  border-top-color: var(--green);
}

.stat-card.short {
  border-top-color: var(--blue);
}

.stat-card.caution {
  border-top-color: var(--red);
}

.stat-card strong {
  display: block;
  margin-bottom: 12px;
  font-size: 30px;
}

.stat-card p,
.step p,
.evidence-list span {
  color: var(--muted);
  line-height: 1.65;
}

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

.step {
  padding: 22px;
}

.step span {
  display: block;
  margin-bottom: 28px;
  color: var(--blue);
  font-weight: 820;
}

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

.evidence-list {
  display: grid;
  gap: 12px;
}

.evidence-list div {
  display: grid;
  grid-template-columns: 180px minmax(0, 1fr);
  gap: 20px;
  align-items: start;
  padding: 22px 24px;
}

.downloads {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.downloads a {
  padding: 11px 14px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
  color: var(--blue);
  font-weight: 760;
}

.footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  margin-top: 40px;
  padding: 28px 48px;
  border-top: 1px solid var(--line);
  color: var(--muted);
}

@media (max-width: 900px) {
  .topbar {
    padding: 0 20px;
  }

  .nav {
    display: none;
  }

  .hero,
  .case-grid,
  .steps {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding-top: 56px;
  }

  .evidence-list div {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .footer {
    flex-direction: column;
    padding: 24px 20px;
  }
}