/* 通用样式 */
body {
  margin: 0;
  font-family: "Segoe UI", Arial, sans-serif;
  background-color: #f9f9f9;
  color: #222;
}

/* 顶部导航栏 */
.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: #111;
  color: #fff;
  padding: 15px 40px;
}

.nav-links a {
  color: #ddd;
  text-decoration: none;
  margin: 0 12px;
  font-weight: 500;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: #00d4ff;
}

/* 主体内容 */
.main-content {
  text-align: center;
  padding: 80px 20px;
}

.features {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  margin-top: 60px;
  gap: 20px;
}

.feature-card {
  background: white;
  border-radius: 12px;
  padding: 30px;
  width: 260px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  transition: transform 0.2s, box-shadow 0.2s;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 4px 14px rgba(0,0,0,0.15);
}

/* 页脚 */
.site-footer {
  background-color: #111;
  color: #ccc;
  text-align: center;
  padding: 20px;
  font-size: 0.9em;
}