/* 全局样式增强 */
body { font-size: 16px; }
.container { padding: 20px 15px; }

/* 响应式优化 */
@media (max-width: 768px) {
  h1 { font-size: 1.5em; }
  .section h2 { font-size: 1.3em; }
  .card-grid { grid-template-columns: 1fr; }
}

/* 按钮样式 */
.btn {
  display: inline-block;
  padding: 10px 20px;
  background: #333;
  color: #fff;
  border-radius: 4px;
  transition: background 0.3s;
}
.btn:hover {
  background: #555;
}

/* 导航增强 */
.main-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
}

@media (max-width: 768px) {
  .main-nav {
    flex-direction: column;
  }
  .main-nav .nav-logo {
    width: 100%;
    text-align: center;
  }
  .main-nav .nav-menu {
    width: 100%;
    flex-wrap: nowrap !important;
    overflow: visible;
  }
}

/* UI Style Variants */
.ui-style-0 { --primary-color: #2c3e50; }
.ui-style-1 { --primary-color: #34495e; }
.ui-style-2 { --primary-color: #16a085; }
.ui-style-3 { --primary-color: #27ae60; }
.ui-style-4 { --primary-color: #2980b9; }
.ui-style-5 { --primary-color: #8e44ad; }
.ui-style-6 { --primary-color: #2c3e50; }
.ui-style-7 { --primary-color: #c0392b; }
.ui-style-8 { --primary-color: #d35400; }
.ui-style-9 { --primary-color: #7f8c8d; }
.ui-style-10 { --primary-color: #1abc9c; }
.ui-style-11 { --primary-color: #3498db; }
.ui-style-12 { --primary-color: #9b59b6; }
.ui-style-13 { --primary-color: #e74c3c; }
.ui-style-14 { --primary-color: #e67e22; }
.ui-style-15 { --primary-color: #95a5a6; }