:root {
      --brand-red: #FF1744;
      --brand-red-active: #E60E39;
      --brand-red-bg: #FFF5F7;
      --text-primary: #333;
      --text-secondary: #666;
      --text-tertiary: #999;
      --bg-page: #F5F5F5;
      --bg-card: #FFF;
      --border-light: #EAEAEA;
    }
    * { margin: 0; padding: 0; box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue", sans-serif;
      background: var(--bg-page);
      color: var(--text-primary);
      padding-bottom: 80px;
      font-size: 14px;
      line-height: 1.5;
    }
    
    /* 导航栏 */
    .nav {
      background: var(--brand-red);
      height: 44px;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
      color: #FFF;
      font-size: 17px;
      font-weight: 500;
    }
    .nav-back {
      position: absolute;
      left: 12px;
      font-size: 18px;
      padding: 8px;
    }
    .nav-more {
      position: absolute;
      right: 12px;
      font-size: 20px;
      letter-spacing: 2px;
    }
    
    /* 卡片 */
    .card {
      background: var(--bg-card);
      margin: 12px 12px 0;
      border-radius: 8px;
      padding: 16px;
    }
    .card-title {
      font-size: 15px;
      font-weight: 600;
      margin-bottom: 12px;
      color: var(--text-primary);
    }
    
    /* 面积网格 */
    .area-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 8px;
    }
    .area-item {
      border: 1px solid var(--border-light);
      border-radius: 4px;
      padding: 10px 6px;
      text-align: center;
      font-size: 13px;
      cursor: pointer;
      position: relative;
    }
    .area-item.selected {
      border-color: var(--brand-red);
      background: var(--brand-red-bg);
      color: var(--brand-red);
    }
    
    /* 摄像头滑块 */
    .camera-slider {
      margin: 12px 0;
    }
    .slider-header {
      display: flex;
      justify-content: space-between;
      margin-bottom: 8px;
      font-size: 13px;
    }
    .slider-header .count {
      font-weight: 600;
      color: var(--brand-red);
    }
    .slider-wrapper {
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .slider {
      flex: 1;
      height: 4px;
      border-radius: 2px;
      background: #E0E0E0;
      position: relative;
    }
    .slider-track {
      height: 100%;
      background: var(--brand-red);
      border-radius: 2px;
      width: 40%;
    }
    .slider-thumb {
      position: absolute;
      left: 40%;
      top: 50%;
      transform: translate(-50%, -50%);
      width: 20px;
      height: 20px;
      background: #FFF;
      border: 2px solid var(--brand-red);
      border-radius: 50%;
      box-shadow: 0 1px 3px rgba(0,0,0,0.2);
    }
    .slider-label {
      font-size: 12px;
      color: var(--text-tertiary);
    }
    
    /* 商品行 */
    .product-row {
      display: flex;
      align-items: center;
      gap: 12px;
      padding: 12px 0;
      border-top: 1px solid var(--border-light);
    }
    .product-row:first-child {
      border-top: none;
    }
    .product-img {
      width: 50px;
      height: 50px;
      background: #F5F5F5;
      border-radius: 4px;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
      font-size: 24px;
    }
    .product-info {
      flex: 1;
    }
    .product-name {
      font-size: 14px;
      font-weight: 500;
      margin-bottom: 4px;
    }
    .product-price {
      font-size: 12px;
      color: var(--text-tertiary);
    }
    .qty-control {
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .qty-btn {
      width: 24px;
      height: 24px;
      border: 1px solid var(--border-light);
      border-radius: 4px;
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      font-size: 16px;
      color: var(--text-secondary);
    }
    .qty-num {
      min-width: 20px;
      text-align: center;
      font-size: 14px;
      font-weight: 500;
    }
    
    /* 存储选项 */
    .storage-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 10px;
    }
    .storage-item {
      border: 1px solid var(--border-light);
      border-radius: 6px;
      padding: 12px;
      cursor: pointer;
      position: relative;
    }
    .storage-item.selected {
      border-color: var(--brand-red);
      background: var(--brand-red-bg);
    }
    .storage-label {
      font-size: 14px;
      font-weight: 600;
      margin-bottom: 4px;
    }
    .storage-item.selected .storage-label {
      color: var(--brand-red);
    }
    .storage-desc {
      font-size: 12px;
      color: var(--text-tertiary);
    }
    .storage-price {
      font-size: 12px;
      color: var(--text-secondary);
      margin-top: 4px;
    }
    
    /* 产品配送清单 */
    .delivery-list {
      font-size: 13px;
    }
    .delivery-item {
      display: flex;
      justify-content: space-between;
      padding: 8px 0;
      border-bottom: 1px solid var(--border-light);
    }
    .delivery-item:last-child {
      border-bottom: none;
    }
    .delivery-name {
      color: var(--text-secondary);
    }
    .delivery-qty {
      color: var(--text-primary);
      font-weight: 500;
    }
    
    /* 推荐商品 */
    .recommend-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 10px;
      margin-top: 12px;
    }
    .recommend-item {
      text-align: center;
    }
    .recommend-img {
      width: 100%;
      aspect-ratio: 1;
      background: #F5F5F5;
      border-radius: 6px;
      margin-bottom: 6px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 32px;
    }
    .recommend-name {
      font-size: 13px;
      margin-bottom: 4px;
    }
    .recommend-price {
      font-size: 14px;
      font-weight: 600;
      color: var(--brand-red);
    }
    
    /* 投保选项 */
    .insurance-list {
      font-size: 13px;
    }
    .insurance-item {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 10px 0;
    }
    .insurance-check {
      width: 18px;
      height: 18px;
      border: 2px solid #4CAF50;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: #4CAF50;
      font-size: 12px;
    }
    
    /* 底部栏 */
    .bottom-bar {
      position: fixed;
      left: 0;
      right: 0;
      bottom: 0;
      background: #FFF;
      border-top: 1px solid var(--border-light);
      padding: 10px 12px;
      padding-bottom: calc(10px + env(safe-area-inset-bottom));
      display: flex;
      align-items: center;
      justify-content: space-between;
      z-index: 100;
    }
    .bottom-price {
      display: flex;
      align-items: baseline;
      gap: 4px;
    }
    .price-label {
      font-size: 13px;
      color: var(--text-tertiary);
    }
    .price-value {
      font-size: 22px;
      font-weight: 700;
      color: var(--brand-red);
    }
    .price-detail {
      font-size: 12px;
      color: var(--text-tertiary);
      margin-top: 2px;
    }
    .pay-btn {
      height: 44px;
      padding: 0 32px;
      background: var(--brand-red);
      color: #FFF;
      border: none;
      border-radius: 22px;
      font-size: 16px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      min-width: 100px;
    }
    .pay-btn:active {
      background: var(--brand-red-active);
    }
    .pay-btn.loading {
      opacity: 0.7;
      pointer-events: none;
    }
    
    /* 缺货弹窗 */
    .modal-overlay {
      display: none;
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.5);
      z-index: 1000;
      align-items: flex-end;
    }
    .modal-overlay.show {
      display: flex;
    }
    .modal {
      background: #FFF;
      border-radius: 16px 16px 0 0;
      width: 100%;
      max-height: 70vh;
      animation: slideUp 0.3s cubic-bezier(0.32, 0.72, 0, 1);
    }
    @keyframes slideUp {
      from { transform: translateY(100%); }
      to { transform: translateY(0); }
    }
    .modal-body {
      padding: 20px;
      max-height: calc(70vh - 80px);
      overflow-y: auto;
      -webkit-overflow-scrolling: touch;
    }
    .modal-title {
      font-size: 17px;
      font-weight: 600;
      text-align: center;
      margin-bottom: 8px;
    }
    .modal-desc {
      font-size: 13px;
      color: var(--text-tertiary);
      line-height: 1.6;
      margin-bottom: 16px;
    }
    .modal-list {
      border-top: 1px solid var(--border-light);
    }
    .modal-item {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 12px 0;
      border-bottom: 1px solid var(--border-light);
    }
    .modal-item:last-child {
      border-bottom: none;
    }
    .modal-item-name {
      font-size: 14px;
    }
    .modal-item-spec {
      font-size: 12px;
      color: var(--text-tertiary);
      margin-top: 2px;
    }
    .stock-tag {
      color: var(--brand-red);
      font-size: 14px;
      font-weight: 500;
    }
    .modal-footer {
      padding: 16px 20px;
      padding-bottom: calc(20px + env(safe-area-inset-bottom));
    }
    .modal-btn {
      width: 100%;
      height: 46px;
      background: var(--brand-red);
      color: #FFF;
      border: none;
      border-radius: 23px;
      font-size: 16px;
      font-weight: 600;
      cursor: pointer;
    }
    
    /* loading */
    .spinner {
      display: inline-block;
      width: 16px;
      height: 16px;
      border: 2px solid rgba(255,255,255,0.3);
      border-top-color: #FFF;
      border-radius: 50%;
      animation: spin 0.6s linear infinite;
      margin-right: 6px;
    }
    @keyframes spin {
      to { transform: rotate(360deg); }
    }