/* Material Design 3 规范 - 优化版 */
        :root {
            /* 颜色系统 - 优化 */
            --md-primary: #6750A4;
            --md-primary-dark: #5A4790;
            --md-background: #F5F5F5; /* 浅灰色背景 */
            --md-surface: #FFFFFF;
            --md-title: #1D1B20;
            --md-body: #6B6B6B;
            --md-caption: #8A8A8F;
            --md-border: #E0E0E0;
            
            /* 圆角系统 */
            --md-radius-small: 8px;
            --md-radius-medium: 12px;
            --md-radius-large: 16px;
            --md-radius-extra-large: 20px;
            
            /* 阴影系统 - 优化 */
            --md-elevation-1: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
            --md-elevation-2: 0 2px 6px rgba(0,0,0,0.1), 0 1px 4px rgba(0,0,0,0.08);
            --md-elevation-3: 0 4px 12px rgba(0,0,0,0.12), 0 2px 8px rgba(0,0,0,0.1);
            
            /* 字体系统 */
            --md-font-title: 18px;
            --md-font-subtitle: 16px;
            --md-font-body: 14px;
            --md-font-caption: 12px;
            
            /* 间距系统 */
            --md-spacing-xs: 4px;
            --md-spacing-sm: 8px;
            --md-spacing-md: 12px;
            --md-spacing-lg: 16px;
            --md-spacing-xl: 20px;
            --md-spacing-xxl: 24px;
        }

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

        html, body {
            height: 100%;
            overflow: hidden;
        }

        body {
            font-family: 'Roboto', 'Noto Sans SC', sans-serif;
            background-color: var(--md-background);
            color: var(--md-body);
            line-height: 1.5;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        /* 应用栏 - 优化 */
        .app-bar {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            height: 64px;
            background: var(--md-surface);
            box-shadow: var(--md-elevation-2);
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            z-index: 1000;
            transform: translateZ(0);
        }

        .app-bar__title {
            font-size: var(--md-font-title);
            font-weight: 600;
            color: var(--md-title);
            margin-bottom: var(--md-spacing-xs);
        }

        .app-bar__subtitle {
            font-size: var(--md-font-caption);
            color: var(--md-caption);
            font-weight: 400;
        }

        /* 主内容区域 - 优化 */
        .main-content {
            position: fixed;
            top: 64px;
            left: 0;
            right: 0;
            bottom: 56px;
            padding: var(--md-spacing-lg);
            overflow-y: auto;
            -webkit-overflow-scrolling: touch;
            overscroll-behavior: contain;
            z-index: 1;
            transform: translateZ(0);
        }

        .main-content::-webkit-scrollbar {
            display: none;
        }

        /* 轮播图 - 优化 */
        .banner-section {
            position: relative;
            margin-bottom: var(--md-spacing-xl);
        }

        .banner-container {
            position: relative;
            width: 100%;
            height: 180px;
            border-radius: var(--md-radius-extra-large);
            overflow: hidden;
            box-shadow: var(--md-elevation-2);
            transform: translateZ(0);
        }

        .banner-slide {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            opacity: 0;
            transition: opacity 0.5s ease;
            background-size: cover;
            background-position: center;
            transform: translateZ(0);
        }

        .banner-slide.active {
            opacity: 1;
        }

        .banner-overlay {
            position: absolute;
            bottom: 0;
            left: 0;
            right: 0;
            padding: var(--md-spacing-lg);
            background: linear-gradient(transparent, rgba(0,0,0,0.7));
            color: white;
        }

        .banner-title {
            font-size: var(--md-font-subtitle);
            font-weight: 600;
            margin-bottom: var(--md-spacing-xs);
        }

        .banner-desc {
            font-size: var(--md-font-caption);
            opacity: 0.9;
        }

        .banner-indicators {
            position: absolute;
            bottom: 12px;
            left: 0;
            right: 0;
            display: flex;
            justify-content: center;
            gap: 6px;
        }

        .banner-indicator {
            width: 6px;
            height: 6px;
            border-radius: 50%;
            background-color: rgba(255,255,255,0.5);
            transition: all 0.3s ease;
        }

        .banner-indicator.active {
            background-color: white;
            width: 20px;
            border-radius: 3px;
        }

        /* Banner 分隔线 - 波浪形 */
        .banner-divider {
            position: absolute;
            bottom: -2px;
            left: 0;
            width: 100%;
            height: 12px;
            background: var(--md-background);
            border-radius: 50% 50% 0 0;
            z-index: 2;
        }

        /* 产品网格 - 优化 */
        .section-title {
            font-size: var(--md-font-subtitle);
            font-weight: 600;
            color: var(--md-title);
            margin: var(--md-spacing-xxl) 0 var(--md-spacing-lg);
            padding-left: var(--md-spacing-sm);
            position: relative;
            transform: translateZ(0);
        }

        .section-title::before {
            content: '';
            position: absolute;
            left: 0;
            top: 50%;
            transform: translateY(-50%);
            width: 3px;
            height: 16px;
            background: var(--md-primary);
            border-radius: 2px;
        }

        .products-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: var(--md-spacing-md);
            margin-bottom: var(--md-spacing-xl);
            transform: translateZ(0);
        }

        .product-card {
            background: var(--md-surface);
            border-radius: var(--md-radius-large);
            overflow: hidden;
            box-shadow: var(--md-elevation-1);
            transition: all 0.3s ease;
            height: 220px;
            transform: translateZ(0);
            backface-visibility: hidden;
            border: 1px solid var(--md-border);
        }

        .product-card:active {
            box-shadow: var(--md-elevation-3);
            transform: translateY(-2px);
        }

        .product-image {
            width: 100%;
            height: 120px; /* 固定图片高度 */
            background-size: cover;
            background-position: center;
            background-repeat: no-repeat;
            position: relative;
            transform: translateZ(0);
        }

        .product-image::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            right: 0;
            height: 1px;
            background: linear-gradient(90deg, transparent, var(--md-border), transparent);
        }

        .product-content {
            padding: var(--md-spacing-md);
            height: 100px;
            display: flex;
            flex-direction: column;
            justify-content: space-between;
            transform: translateZ(0);
        }

        .product-text {
            flex: 1;
            display: flex;
            flex-direction: column;
            justify-content: flex-start;
        }

        .product-title {
            font-size: var(--md-font-body);
            font-weight: 600;
            color: var(--md-title);
            margin-bottom: var(--md-spacing-xs);
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
            line-height: 1.3;
            min-height: 36px;
        }

        .product-desc {
            font-size: var(--md-font-caption);
            color: var(--md-caption);
            display: -webkit-box;
            -webkit-line-clamp: 1;
            -webkit-box-orient: vertical;
            overflow: hidden;
            line-height: 1.2;
            margin-top: -10px; 
        }

        .order-button {
            background: var(--md-primary);
            color: white;
            border: none;
            border-radius: var(--md-radius-small);
            height: 32px;
            width: 100%;
            font-size: var(--md-font-body);
            font-weight: 500;
            cursor: pointer;
            transition: all 0.2s ease;
            text-decoration: none !important;
            display: flex;
            align-items: center;
            justify-content: center;
            transform: translateZ(0);
        }

        .order-button:active {
            background: var(--md-primary-dark);
            transform: scale(0.98);
        }

        /* 底部导航 - 优化 */
        .bottom-nav {
            position: fixed;
            bottom: 0;
            left: 0;
            right: 0;
            height: 56px;
            background: var(--md-surface);
            box-shadow: 0 -2px 8px rgba(0,0,0,0.08);
            display: flex;
            z-index: 1000;
            transform: translateZ(0);
            border-top: 1px solid var(--md-border);
        }

        .nav-item {
            flex: 1;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            text-decoration: none !important;
            color: var(--md-caption);
            position: relative;
            transition: all 0.2s ease;
        }

        .nav-item.active {
            color: var(--md-primary);
        }

        .nav-item.active::after {
            content: '';
            position: absolute;
            bottom: 0;
            width: 24px;
            height: 3px;
            background-color: var(--md-primary);
            border-radius: 2px;
        }

        .nav-icon {
            font-size: 22px;
            margin-bottom: var(--md-spacing-xs);
            transition: all 0.2s ease;
        }

        .nav-item.active .nav-icon {
            transform: scale(1.1);
        }

        .nav-label {
            font-size: var(--md-font-caption);
            font-weight: 500;
        }

        /* 公告弹窗 - 优化 */
        .popup-overlay {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(0,0,0,0.6);
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 2000;
            padding: var(--md-spacing-lg);
            transform: translateZ(0);
        }

        .popup-container {
            background: var(--md-surface);
            border-radius: var(--md-radius-extra-large);
            box-shadow: var(--md-elevation-3);
            width: 85%;
            max-width: 400px;
            overflow: hidden;
            transform: translateZ(0);
        }

        .popup-header {
            padding: var(--md-spacing-lg);
            display: flex;
            justify-content: space-between;
            align-items: center;
            border-bottom: 1px solid var(--md-border);
        }

        .popup-title {
            font-size: var(--md-font-subtitle);
            font-weight: 600;
            color: var(--md-title);
        }

        .popup-close {
            background: none;
            border: none;
            color: var(--md-caption);
            cursor: pointer;
            font-size: 20px;
            width: 32px;
            height: 32px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: background-color 0.2s ease;
        }

        .popup-close:active {
            background-color: var(--md-background);
        }

        .popup-content {
            padding: var(--md-spacing-lg);
            max-height: 200px;
            overflow-y: auto;
        }

        .popup-text {
            font-size: var(--md-font-body);
            color: var(--md-title);
            line-height: 1.5;
        }

        .popup-footer {
            padding: var(--md-spacing-lg);
            border-top: 1px solid var(--md-border);
        }

        .popup-button {
            background: var(--md-primary);
            color: white;
            border: none;
            border-radius: var(--md-radius-small);
            height: 40px;
            width: 100%;
            font-size: var(--md-font-body);
            font-weight: 500;
            cursor: pointer;
            text-decoration: none !important;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all 0.2s ease;
        }

        .popup-button:active {
            background: var(--md-primary-dark);
            transform: scale(0.98);
        }

        /* 链接样式 */
        a {
            text-decoration: none !important;
        }

        /* 响应式优化 */
        @media (max-width: 480px) {
            .main-content {
                padding: var(--md-spacing-md);
            }
            
            .products-grid {
                gap: var(--md-spacing-sm);
            }
            
            .product-card {
                height: 200px;
            }
            
            .product-image {
                height: 100px;
            }
            
            .product-content {
                padding: var(--md-spacing-sm);
                height: 100px;
            }
        }

        @media (max-width: 360px) {
            .products-grid {
                grid-template-columns: 1fr;
            }
        }