:root {
  --bg: #f0f2f5;
  --card-bg: #fff;
  --text: #1a1a2e;
  --text-secondary: #6b7280;
  --primary: #4f46e5;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.08);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.hero {
  text-align: center;
  margin-bottom: 40px;
}

.hero h1 {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 8px;
}

.hero p {
  color: var(--text-secondary);
  font-size: 16px;
}

.nav-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  max-width: 700px;
  width: 90%;
}

.nav-card {
  background: var(--card-bg);
  border-radius: 12px;
  padding: 28px 24px;
  box-shadow: var(--shadow);
  text-decoration: none;
  color: var(--text);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  transition:
    transform 0.2s,
    box-shadow 0.2s;
  cursor: pointer;
  border: 2px solid transparent;
}

.nav-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary);
}

.nav-card .icon {
  font-size: 36px;
}

.nav-card .title {
  font-size: 16px;
  font-weight: 600;
}

.nav-card .desc {
  font-size: 13px;
  color: var(--text-secondary);
  text-align: center;
}

.footer {
  margin-top: 48px;
  font-size: 12px;
  color: var(--text-secondary);
}