:root {
  color-scheme: light;
  --bg: #fbfaf7;
  --panel: #ffffff;
  --ink: #161513;
  --muted: #6d6a62;
  --line: #e7e1d7;
  --brand: #155e75;
  --brand-dark: #0f3f4f;
  --warm: #f4efe6;
  --soft: #e8f4f3;
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: var(--bg);
}

body {
  min-height: 100vh;
  margin: 0;
  background:
    radial-gradient(circle at 15% 12%, rgba(21, 94, 117, 0.12), transparent 28rem),
    linear-gradient(180deg, #fffdf9 0%, var(--bg) 55%, #f5f8f7 100%);
  color: var(--ink);
}

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

.site-header,
.site-footer {
  display: flex;
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  align-items: center;
  justify-content: space-between;
}

.site-header {
  min-height: 76px;
}

.brand,
.nav-actions,
.hero-actions,
.button,
.preview-topbar,
.composer-line {
  display: flex;
  align-items: center;
}

.brand {
  gap: 10px;
  font-size: 18px;
  font-weight: 760;
}

.brand-mark {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border-radius: 8px;
  background: var(--brand);
  color: white;
  font-size: 14px;
  font-weight: 800;
}

.nav-actions {
  gap: 8px;
}

.nav-actions a {
  border-radius: 8px;
  padding: 10px 14px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 650;
}

.nav-actions a:hover {
  background: rgba(255, 255, 255, 0.78);
  color: var(--ink);
}

.nav-actions .nav-primary {
  background: var(--ink);
  color: white;
}

.hero {
  display: grid;
  width: min(1120px, calc(100% - 32px));
  min-height: calc(100vh - 150px);
  margin: 0 auto;
  grid-template-columns: minmax(0, 0.95fr) minmax(360px, 1.05fr);
  align-items: center;
  gap: 54px;
  padding: 44px 0 56px;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--brand);
  font-size: 13px;
  font-weight: 780;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1 {
  max-width: 720px;
  margin: 0;
  font-size: clamp(42px, 7vw, 76px);
  line-height: 1.02;
  letter-spacing: 0;
}

.lead {
  max-width: 620px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.86;
}

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

.button {
  min-height: 48px;
  justify-content: center;
  border-radius: 8px;
  padding: 0 22px;
  font-size: 15px;
  font-weight: 760;
}

.button.primary {
  background: var(--brand);
  color: white;
  box-shadow: 0 18px 42px rgba(21, 94, 117, 0.22);
}

.button.primary:hover {
  background: var(--brand-dark);
}

.button.secondary {
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.72);
}

.button.secondary:hover {
  background: white;
}

.product-preview {
  overflow: hidden;
  border: 1px solid rgba(22, 21, 19, 0.1);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.82);
  box-shadow: 0 28px 90px rgba(22, 21, 19, 0.14);
}

.preview-topbar {
  height: 44px;
  gap: 7px;
  border-bottom: 1px solid var(--line);
  padding: 0 16px;
}

.preview-topbar span {
  width: 10px;
  height: 10px;
  border-radius: 999px;
  background: #d7d0c5;
}

.preview-body {
  display: grid;
  min-height: 438px;
  grid-template-columns: 142px minmax(0, 1fr);
}

.preview-sidebar {
  display: grid;
  align-content: start;
  gap: 12px;
  padding: 20px 14px;
  background: var(--warm);
}

.preview-sidebar div {
  height: 34px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.72);
}

.preview-sidebar div:first-child {
  background: var(--soft);
}

.preview-chat {
  display: flex;
  min-width: 0;
  flex-direction: column;
  gap: 18px;
  justify-content: center;
  padding: 36px;
}

.message {
  max-width: 88%;
  border-radius: 8px;
  font-size: 15px;
  line-height: 1.7;
}

.message.assistant {
  padding: 16px 18px;
  background: #f6f8f7;
}

.message.assistant strong {
  display: block;
  margin-bottom: 6px;
  color: var(--brand);
}

.message.assistant p {
  margin: 0;
  color: var(--muted);
}

.message.user {
  align-self: flex-end;
  padding: 12px 16px;
  background: var(--brand);
  color: white;
}

.composer-line {
  min-height: 52px;
  justify-content: space-between;
  gap: 14px;
  margin-top: 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 12px 0 16px;
  background: white;
  color: #9a958b;
}

.composer-line b {
  display: grid;
  width: 32px;
  height: 32px;
  place-items: center;
  border-radius: 8px;
  background: var(--ink);
  color: white;
}

.features {
  display: grid;
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  padding: 0 0 64px;
}

.features article {
  min-height: 164px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 22px;
  background: rgba(255, 255, 255, 0.68);
}

.features span {
  color: var(--brand);
  font-size: 13px;
  font-weight: 780;
}

.features h2 {
  margin: 20px 0 8px;
  font-size: 20px;
}

.features p {
  margin: 0;
  color: var(--muted);
  line-height: 1.72;
}

.pricing {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 18px 0 72px;
}

.section-heading {
  max-width: 720px;
  margin-bottom: 28px;
}

.section-heading h2 {
  margin: 0;
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.08;
}

.section-heading p:not(.eyebrow) {
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.78;
}

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

.plan-card {
  display: flex;
  min-height: 330px;
  flex-direction: column;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 22px;
  background: rgba(255, 255, 255, 0.76);
  box-shadow: 0 18px 48px rgba(22, 21, 19, 0.07);
}

.plan-card.is-featured {
  border-color: rgba(21, 94, 117, 0.44);
  background: linear-gradient(180deg, #ffffff 0%, #eaf6f5 100%);
  box-shadow: 0 24px 70px rgba(21, 94, 117, 0.18);
  transform: translateY(-8px);
}

.plan-tag {
  align-self: flex-start;
  border-radius: 999px;
  background: var(--soft);
  padding: 7px 10px;
  color: var(--brand);
  font-size: 12px;
  font-weight: 780;
}

.plan-card.is-featured .plan-tag {
  background: var(--brand);
  color: white;
}

.plan-card h3 {
  margin: 18px 0 6px;
  font-size: 20px;
}

.plan-price {
  margin-top: 2px;
  font-size: 42px;
  font-weight: 860;
  line-height: 1;
}

.plan-card strong {
  margin-top: 12px;
  font-size: 18px;
}

.plan-card ul {
  display: grid;
  gap: 8px;
  margin: 18px 0 22px;
  padding: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.55;
  list-style: none;
}

.plan-card li::before {
  content: "✓";
  margin-right: 8px;
  color: var(--brand);
  font-weight: 800;
}

.plan-card .button {
  width: 100%;
  margin-top: auto;
  padding: 0 12px;
}

.credit-usage {
  display: flex;
  gap: 20px;
  align-items: flex-start;
  justify-content: space-between;
  margin-top: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 18px 20px;
  background: rgba(255, 255, 255, 0.68);
}

.credit-usage span {
  color: var(--brand);
  font-size: 14px;
  font-weight: 800;
}

.credit-usage ul {
  display: grid;
  flex: 1;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  margin: 0;
  padding: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
  list-style: none;
}

.site-footer {
  min-height: 72px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
}

.site-footer a {
  color: var(--brand);
  font-weight: 700;
}

@media (max-width: 900px) {
  .hero {
    min-height: auto;
    grid-template-columns: 1fr;
    gap: 34px;
    padding-top: 28px;
  }

  .product-preview {
    max-width: 680px;
  }

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

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

  .plan-card.is-featured {
    transform: none;
  }

  .credit-usage {
    display: grid;
  }

  .credit-usage ul {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 600px) {
  .site-header {
    min-height: 68px;
  }

  .brand {
    font-size: 16px;
  }

  .brand-mark {
    width: 34px;
    height: 34px;
  }

  .nav-actions a:first-child {
    display: none;
  }

  .nav-actions {
    gap: 4px;
  }

  .nav-actions a {
    padding: 9px 10px;
    font-size: 13px;
  }

  h1 {
    font-size: 42px;
  }

  .lead {
    font-size: 16px;
  }

  .button {
    width: 100%;
  }

  .preview-body {
    min-height: 360px;
    grid-template-columns: 1fr;
  }

  .preview-sidebar {
    display: none;
  }

  .preview-chat {
    padding: 24px;
  }

  .pricing {
    padding-bottom: 52px;
  }

  .plan-grid,
  .credit-usage ul {
    grid-template-columns: 1fr;
  }

  .plan-card {
    min-height: 0;
  }

  .site-footer {
    align-items: flex-start;
    flex-direction: column;
    justify-content: center;
    gap: 6px;
  }
}