:root {
  color-scheme: light;
  --bg: #f6f7f4;
  --surface: #ffffff;
  --surface-soft: #f0f4ee;
  --ink: #17201b;
  --muted: #607067;
  --line: #d9e0d9;
  --accent: #246b4f;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
  padding: 16px clamp(18px, 4vw, 56px);
  background: rgba(246, 247, 244, 0.88);
  border-bottom: 1px solid rgba(217, 224, 217, 0.9);
  backdrop-filter: blur(16px);
}

.brand {
  font-size: 19px;
  font-weight: 720;
  letter-spacing: 0;
}

.shell {
  width: min(980px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 56px;
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
}

.tool-card {
  display: flex;
  align-items: center;
  min-height: 72px;
  padding: 18px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 8px 22px rgba(33, 45, 37, 0.06);
  transition:
    transform 160ms ease,
    border-color 160ms ease,
    box-shadow 160ms ease;
}

.tool-card:hover,
.tool-card:focus-visible {
  transform: translateY(-1px);
  border-color: rgba(36, 107, 79, 0.42);
  box-shadow: 0 12px 28px rgba(33, 45, 37, 0.1);
  outline: none;
}

.tool-card h2 {
  margin: 0;
  font-size: 18px;
  line-height: 1.28;
  letter-spacing: 0;
}

.tool-card h2::after {
  content: "↗";
  margin-left: 8px;
  color: var(--accent);
  font-size: 14px;
  font-weight: 650;
}

@media (max-width: 640px) {
  .topbar {
    align-items: flex-start;
    min-height: auto;
  }

  .subhead {
    max-width: 28rem;
  }

  .shell {
    width: min(100% - 24px, 1120px);
    padding-top: 18px;
  }

  .tool-card {
    min-height: 66px;
    padding: 16px;
  }
}