/* ===== 全局重置 ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
  color: #1a1a2e;
  background: #f8f9fa;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a { text-decoration: none; color: inherit; }
img { max-width: 100%; }
.container { max-width: 960px; margin: 0 auto; padding: 0 1.5rem; }

/* ===== 导航栏 ===== */
.navbar {
  background: #fff;
  border-bottom: 1px solid #e9ecef;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
  background: rgba(255,255,255,0.9);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 3.5rem;
}

.logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: #4361ee;
}

.nav-links { display: flex; gap: 1.5rem; }
.nav-links a {
  font-size: 0.9rem;
  color: #555;
  transition: color 0.2s;
}
.nav-links a:hover,
.nav-links a.active { color: #4361ee; }

/* ===== Hero ===== */
.hero {
  padding: 4rem 0 3rem;
  text-align: center;
}

.hero h1 {
  font-size: 2.25rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.subtitle {
  font-size: 1.05rem;
  color: #666;
  max-width: 540px;
  margin: 0 auto;
}

/* ===== 子应用卡片 ===== */
.apps { padding: 2rem 0 4rem; }
.apps h2 {
  font-size: 1.4rem;
  margin-bottom: 1.5rem;
  color: #333;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.25rem;
}

.card {
  background: #fff;
  border: 1px solid #e9ecef;
  border-radius: 12px;
  padding: 1.5rem;
  transition: transform 0.2s, box-shadow 0.2s;
  display: flex;
  flex-direction: column;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.08);
  border-color: #4361ee;
}

.card-icon { font-size: 2rem; margin-bottom: 0.75rem; }
.card h3 { font-size: 1.1rem; margin-bottom: 0.4rem; }
.card p { font-size: 0.88rem; color: #666; flex: 1; }

.card-tag {
  display: inline-block;
  margin-top: 0.75rem;
  font-size: 0.78rem;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  background: #eef0ff;
  color: #4361ee;
  align-self: flex-start;
}

/* ===== 页脚 ===== */
.footer {
  margin-top: auto;
  padding: 1.5rem 0;
  text-align: center;
  font-size: 0.85rem;
  color: #999;
  border-top: 1px solid #e9ecef;
}

/* ===== 响应式 ===== */
@media (max-width: 600px) {
  .hero h1 { font-size: 1.6rem; }
  .nav-links { gap: 1rem; }
  .card-grid { grid-template-columns: 1fr; }
}