:root {
  --bg: #ffffff;
  --ink: #17201f;
  --muted: #5f6d69;
  --line: #d9e1de;
  --panel: #f4f8f7;
  --panel-strong: #e6f1ee;
  --teal: #0f766e;
  --teal-dark: #0b5752;
  --amber: #b7791f;
  --shadow: 0 18px 50px rgba(18, 36, 34, 0.08);
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Segoe UI", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.6;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  padding: 18px clamp(22px, 5vw, 72px);
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  letter-spacing: 0;
}

.brand-mark {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  background: var(--ink);
  color: #ffffff;
  border-radius: 6px;
  font-size: 13px;
}

.nav-links {
  display: flex;
  gap: 22px;
  color: var(--muted);
  font-size: 14px;
}

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

.language-switcher {
  display: inline-flex;
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #ffffff;
}

.language-button {
  min-width: 44px;
  min-height: 32px;
  border: 0;
  border-radius: 4px;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
}

.language-button.active {
  background: var(--ink);
  color: #ffffff;
}

.hero {
  min-height: 88vh;
  display: flex;
  align-items: center;
  border-bottom: 1px solid var(--line);
}

.hero-inner,
.section-inner {
  width: min(1140px, calc(100% - 44px));
  margin: 0 auto;
}

.hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.72fr);
  gap: clamp(34px, 6vw, 84px);
  align-items: center;
  padding: 70px 0 64px;
}

.hero h1 {
  max-width: 820px;
  margin: 0;
  font-size: clamp(46px, 7vw, 88px);
  line-height: 0.95;
  letter-spacing: 0;
}

.lead {
  max-width: 680px;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: clamp(18px, 2vw, 22px);
}

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

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--ink);
  font-size: 14px;
  font-weight: 650;
}

.button.primary {
  background: var(--teal);
  border-color: var(--teal);
  color: #ffffff;
}

.button:hover {
  border-color: var(--teal);
}

.hero-proof {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: var(--shadow);
}

.ci-badge {
  display: block;
  max-width: 100%;
  height: 22px;
  margin-bottom: 20px;
}

.proof-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  margin: 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.proof-grid div {
  background: #ffffff;
  padding: 22px;
}

.proof-grid dt {
  font-size: 42px;
  font-weight: 760;
  line-height: 1;
}

.proof-grid dd {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.proof-note {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.section {
  padding: 86px 0;
}

.band {
  background: var(--panel);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.section-heading {
  display: grid;
  grid-template-columns: minmax(220px, 0.45fr) minmax(0, 0.55fr);
  gap: 42px;
  align-items: start;
  margin-bottom: 36px;
}

h2 {
  margin: 0;
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.04;
  letter-spacing: 0;
}

h3 {
  margin: 0 0 10px;
  font-size: 18px;
  line-height: 1.25;
}

.section-heading p,
.feature-list p,
.timeline p,
.split p,
.boundary li {
  margin: 0;
  color: var(--muted);
}

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

.feature-list article {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  background: #ffffff;
}

.timeline {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.timeline li {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 18px;
  align-items: start;
  padding: 20px;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.timeline span {
  display: grid;
  width: 40px;
  height: 40px;
  place-items: center;
  background: var(--panel-strong);
  color: var(--teal-dark);
  border-radius: 6px;
  font-weight: 760;
}

.contribution-table {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.table-row {
  display: grid;
  grid-template-columns: 1.1fr 0.3fr 1.35fr 0.32fr;
  gap: 18px;
  padding: 18px 20px;
  border-top: 1px solid var(--line);
  color: var(--muted);
}

.table-row:first-child {
  border-top: 0;
}

.table-head {
  background: var(--ink);
  color: #ffffff;
  font-weight: 700;
}

a.table-row:hover {
  background: var(--panel);
  color: var(--ink);
}

.split {
  display: grid;
  grid-template-columns: 0.8fr 1fr;
  gap: 48px;
  align-items: center;
}

.split p {
  margin-top: 18px;
  max-width: 560px;
}

.supplement-card {
  display: grid;
  gap: 14px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
}

.supplement-card strong {
  font-size: 22px;
  line-height: 1.25;
}

.supplement-card span {
  color: var(--muted);
}

.supplement-points {
  margin: 2px 0 0;
  padding-left: 20px;
  color: var(--muted);
}

.supplement-points li + li {
  margin-top: 8px;
}

.supplement-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 6px;
}

.case-card {
  display: grid;
  gap: 16px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #ffffff;
  box-shadow: var(--shadow);
}

.case-card strong {
  font-size: 22px;
  line-height: 1.25;
}

.case-card ul {
  margin: 0;
  padding-left: 20px;
  color: var(--muted);
}

.case-card li + li {
  margin-top: 8px;
}

.verification-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

.verification-grid a {
  display: grid;
  gap: 8px;
  min-height: 134px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #ffffff;
}

.verification-grid a:hover {
  border-color: var(--teal);
}

.verification-grid strong,
.verification-grid span {
  display: block;
}

.verification-grid span {
  color: var(--muted);
  font-size: 14px;
}

.plan-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.plan-grid div {
  min-height: 112px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #ffffff;
}

.plan-grid strong,
.plan-grid span {
  display: block;
}

.plan-grid strong {
  color: var(--amber);
  margin-bottom: 10px;
}

.boundary {
  border-left: 4px solid var(--teal);
  padding-left: 28px;
}

.boundary ul {
  margin: 22px 0 0;
  padding-left: 20px;
}

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

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 28px clamp(22px, 5vw, 72px);
  color: var(--muted);
  border-top: 1px solid var(--line);
  font-size: 14px;
}

.site-footer a {
  color: var(--teal-dark);
  font-weight: 650;
}

@media (max-width: 860px) {
  .site-header,
  .site-footer {
    align-items: flex-start;
    flex-direction: column;
  }

  .nav-links {
    flex-wrap: wrap;
    gap: 14px;
  }

  .language-switcher {
    align-self: stretch;
  }

  .language-button {
    flex: 1;
  }

  .hero-inner,
  .section-heading,
  .feature-list,
  .verification-grid,
  .split {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .hero-inner {
    padding: 52px 0;
  }

  .table-row {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .plan-grid {
    grid-template-columns: 1fr;
  }
}