:root {
  color-scheme: light;
  --ink: #172033;
  --muted: #687386;
  --line: #dbe2ea;
  --surface: rgba(255, 255, 255, 0.88);
  --panel: #ffffff;
  --shadow: 0 24px 70px rgba(26, 36, 54, 0.14);
}

* {
  box-sizing: border-box;
}

body {
  min-height: 100vh;
  margin: 0;
  font-family: Inter, "Segoe UI", "Microsoft YaHei", Arial, sans-serif;
  letter-spacing: 0;
  color: var(--ink);
  background:
    linear-gradient(135deg, rgba(231, 240, 250, 0.96), rgba(245, 248, 243, 0.9) 44%, rgba(250, 244, 236, 0.92)),
    #f3f6f8;
}

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

.shell {
  width: min(1120px, calc(100% - 40px));
  min-height: 100vh;
  margin: 0 auto;
  padding: 28px 0 40px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 10px 0 26px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  min-width: 0;
}

.brand img {
  width: 52px;
  height: 52px;
  border-radius: 8px;
  object-fit: cover;
  box-shadow: 0 10px 26px rgba(23, 32, 51, 0.18);
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  font-size: 18px;
  line-height: 1.25;
}

.brand small,
#clock {
  color: var(--muted);
  font-size: 13px;
}

#clock {
  white-space: nowrap;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: end;
  gap: 28px;
  padding: 54px 0 38px;
}

.eyebrow {
  margin: 0 0 14px;
  color: #1d7a6d;
  font-size: 13px;
  font-weight: 700;
}

h1 {
  max-width: 760px;
  margin: 0;
  font-size: clamp(34px, 6vw, 64px);
  line-height: 1.04;
  font-weight: 850;
}

.primary-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 48px;
  padding: 0 18px;
  border: 1px solid #162033;
  border-radius: 8px;
  color: #fff;
  background: #162033;
  box-shadow: 0 16px 36px rgba(22, 32, 51, 0.2);
}

.nav-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.nav-card {
  position: relative;
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr) 28px;
  align-items: center;
  gap: 16px;
  min-height: 124px;
  padding: 24px;
  border: 1px solid rgba(219, 226, 234, 0.95);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease;
}

.nav-card:hover {
  transform: translateY(-3px);
  border-color: rgba(70, 83, 105, 0.34);
  background: #fff;
}

.icon {
  display: inline-grid;
  place-items: center;
  width: 58px;
  height: 58px;
  border-radius: 8px;
  color: #fff;
  font-size: 24px;
}

.image-icon img {
  width: 38px;
  height: 38px;
  object-fit: contain;
}

.accent-topic .image-icon {
  background: transparent;
}

.accent-topic .image-icon img {
  width: 58px;
  height: 58px;
}

.copy {
  min-width: 0;
}

.copy strong,
.copy small {
  display: block;
}

.copy strong {
  overflow-wrap: anywhere;
  font-size: 23px;
  line-height: 1.25;
}

.copy small {
  margin-top: 8px;
  color: var(--muted);
  font-size: 14px;
  overflow-wrap: anywhere;
}

.open-icon {
  color: #7b8798;
  font-size: 16px;
}

.accent-review .icon { background: #176b87; }
.accent-data .icon { background: #6b7d35; }
.accent-ai .icon { background: #6f4aa8; }
.accent-topic .icon { background: #b04f3b; }

@media (max-width: 760px) {
  .shell {
    width: min(100% - 28px, 560px);
    padding-top: 18px;
  }

  .topbar,
  .hero {
    align-items: start;
    grid-template-columns: 1fr;
  }

  .topbar {
    flex-direction: column;
    padding-bottom: 14px;
  }

  .hero {
    padding: 34px 0 28px;
  }

  .primary-link {
    width: 100%;
  }

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

  .nav-card {
    grid-template-columns: 52px minmax(0, 1fr) 22px;
    min-height: 108px;
    padding: 18px;
  }

  .icon {
    width: 52px;
    height: 52px;
  }

  .accent-topic .image-icon img {
    width: 52px;
    height: 52px;
  }

  .copy strong {
    font-size: 19px;
  }
}