:root {
            --primary-color: #5da5a7;
            --secondary-color: #447278;
            --text-color: #333;
            --light-text: white;
            --container-width: min(1300px, 90%);
            --content-width: min(900px, 90%);
        }

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

        /* 全局重置 - 消除所有边距和空隙 */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        html,
        body {
            width: 100%;
            overflow-x: hidden;
            position: relative;
        }

        body {
            min-height: 100vh;
            display: flex;
            flex-direction: column;
            background-color: white;
            /* 备用背景色 */
        }

        /* 背景图 - 确保完全覆盖 */
        body::before {
            content: "";
            position: fixed;
            top: 0;
            left: 0;
            width: 100vw;
            height: 100vh;
            background-image: url(images/background.webp);
            background-size: cover;
            background-position: center;
            opacity: 0.4;
            z-index: -1;
        }

        /* 顶部横幅 */
        .top-section {
            width: 100vw;
            height: 150px;
            overflow: hidden;
            position: relative;
            left: 50%;
            transform: translateX(-50%);
        }

        .top-section img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        .navbar-1 {
            width: 100%;
            min-height: 60px;
            /* 初始高度 */
            background-color: #5da5a7;
            display: flex;
            justify-content: center;
            padding: 10px 0;
            /* 增加上下内边距 */
            transition: min-height 0.3s ease;
            /* 高度变化动画 */
        }

        .nav-area-1 {
            width: 100%;
            max-width: 800px;
            height: auto;
            display: flex;
            flex-wrap: wrap;
            /* 启用换行 */
            justify-content: center;
            align-items: center;
            gap: 5px;
            /* 项目间距 */
        }

        .nav-item-1 {
            flex: 1;
            /* 弹性伸缩 */
            min-width: 80px;
            /* 最小宽度限制 */
            max-width: 100px;
            /* 最大宽度限制 */
            height: 60px;
            display: flex;
            justify-content: center;
            align-items: center;
            font-size: clamp(12px, 3vw, 22px);
        }

        .nav-item-1 a {
            color: white;
            text-decoration: none;
        }

        .navbar-1 .nav-item-1 a:hover {
            color: #447278;
        }

        /* 智能换行控制 */
        @media (max-width: 700px) {
            .nav-item-1 {
                min-width: calc(25% - 10px);
                /* 四列布局 */
                max-width: calc(25% - 10px);
            }
        }

        /* 超小屏幕优化 */
        @media (max-width: 480px) {
            .nav-item-1 {
                min-width: calc(25% - 10px);
                /* 两列布局 */
                max-width: calc(25% - 10px);
                height: 50px;
                font-size: clamp(10px, 2.5vw, 14px);
            }
        }

        @media (max-width: 480px) {
            .navbar-1 {
                height: 80px;
                padding: 5px 0;
                overflow: hidden;
            }

            .nav-item-1 {
                width: 25%;
                height: 35px;
                font-size: 12px;
                padding: 0 2px;
            }

            .nav-item-1 a {
                white-space: nowrap;
                overflow: hidden;
                text-overflow: ellipsis;
                display: block;
                width: 100%;
                text-align: center;
                font-size: 12px;
            }

            .top-section {
                height: 120px;
            }
        }

                /* 顶部标题栏 - 修复版本 */
        .container-1 {
            width: 100%;
            height: 80px;
            background-color: white;
            display: flex;
            align-items: center;
            justify-content: center; /* 主要内容居中 */
            position: relative;
            border-bottom: 1px solid #e0e0e0;
        }

        /* 返回按钮固定在左侧 */
        .back-icon {
            width: 80px;
            height: 40px;
            background-image: url('images/back.webp');
            background-size: contain;
            background-repeat: no-repeat;
            background-position: center;
            position: absolute;
            left: 20px;
            top: 50%;
            transform: translateY(-50%);
            cursor: pointer;
            z-index: 1;
        }

        /* 标题完美居中 */
        .text {
            font-size: clamp(24px, 6vw, 60px);
            color: #5da5a7;
            text-align: center;
            margin: 0;
            padding: 0;
            width: 100%;
        }

        /* 响应式调整 */
        @media (max-width: 768px) {
               .container-1 {
                height: 70px;
            }
            .back-icon {
                width: 60px;
                height: 30px;
                left: 15px;
            }

}

        @media (max-width: 480px) {
             .container-1 {
                height: 60px;
            }
            .back-icon {
                width: 50px;
                height: 25px;
                left: 10px;
            }
            .text {
                font-size: 24px;
            }
        }

        /* 内容区域 */
        .container-2 {
            width: var(--container-width);
            background-color: var(--primary-color);
            margin: 0 auto;
            padding: 1.5rem 0;
            display: flex;
            flex-direction: column;
            align-items: center;
            box-sizing: border-box;
        }

        .image {
            width: var(--content-width);
            height: auto;
            max-width: 100%;
            object-fit: contain;
            margin-top: 1.5rem;
        }

        .text-area {
            width: var(--content-width);
            margin-top: 1.5rem;
            padding: 1rem;
            font-size: clamp(1rem, 1.2vw, 1.125rem);
            font-weight: bold;
            background-color: white;
            box-sizing: border-box;
            text-align: center;
            color: var(--primary-color);
            border-radius: 4px;
        }

        /* 下载列表 */
        .download-list {
            width: var(--content-width);
            margin: 1.5rem auto;
        }

        .download-item {
            background-color: white;
            padding: 1.25rem;
            margin-bottom: 1rem;
            display: flex;
            flex-direction: column;
            gap: 1rem;
            border-radius: 4px;
        }

        .download-description {
            width: 100%;
        }

        .download-description h3 {
            margin: 0 0 0.5rem 0;
            color: var(--primary-color);
            font-size: 1.25rem;
        }

        .download-description p {
            margin: 0;
            color: var(--text-color);
        }

        .download-buttons {
            display: flex;
            gap: 1rem;
            justify-content: flex-end;
            flex-wrap: wrap;
        }

        .preview-btn,
        .download-btn {
            padding: 0.625rem 1.25rem;
            border: none;
            border-radius: 4px;
            cursor: pointer;
            font-size: 1rem;
            transition: all 0.3s;
            min-width: 100px;
        }

        .preview-btn {
            background-color: var(--primary-color);
            color: white;
        }

        .download-btn {
            background-color: var(--secondary-color);
            color: white;
        }

        .preview-btn:hover,
        .download-btn:hover {
            opacity: 0.8;
            transform: translateY(-2px);
        }

        /* 模态框基础样式 */
        .modal {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0, 0, 0, 0.8);
            z-index: 1000;
            overflow: auto;
            touch-action: none;
        }

        .modal-content {
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            transition: transform 0.3s ease;
            max-width: 90%;
            max-height: 90%;
        }

        .modal-img {
            display: block;
            max-width: 100%;
            max-height: 90vh;
            cursor: move;
            user-select: none;
            -webkit-user-drag: none;
        }

        .close-modal {
            position: absolute;
            top: 15px;
            right: 35px;
            color: #fff;
            font-size: 40px;
            font-weight: bold;
            cursor: pointer;
            z-index: 1001;
        }

        .zoom-controls {
            position: fixed;
            bottom: 20px;
            left: 50%;
            transform: translateX(-50%);
            display: flex;
            gap: 10px;
            z-index: 1001;
        }

        .zoom-btn {
            background-color: rgba(255, 255, 255, 0.7);
            border: none;
            color: #333;
            font-size: 20px;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .reset-btn {
            background-color: rgba(255, 255, 255, 0.7);
            border: none;
            color: #333;
            font-size: 16px;
            padding: 0 15px;
            height: 40px;
            border-radius: 20px;
            cursor: pointer;
        }

        /* 响应式调整 */
        @media (max-width: 1024px) {

            .back-icon {
                width: 50px;
                height: 40px;
            }
        }

        @media (max-width: 768px) {
            .text {
                font-size: 2rem;
            }

            .download-item {
                padding: 1rem;
            }

            .download-buttons {
                justify-content: center;
            }

            .preview-btn,
            .download-btn {
                width: 100%;
            }
        }

        @media (max-width: 480px) {

            .back-icon {
                width: 40px;
                height: 30px;
            }

            .text {
                font-size: 1.5rem;
            }

            .text-area {
                padding: 0.75rem;
                font-size: 0.9rem;
            }

            .download-description h3 {
                font-size: 1.1rem;
            }

            .close-modal {
                font-size: 2rem;
                top: 0.5rem;
                right: 1rem;
            }
        }

        .download-description a {
            color: #5da5a7;
            /* 和导航栏同色系但不同颜色 */
            font-weight: bold;
            /* 可选：加粗 */
        }

        .download-description a:hover {
            color: #447278;
            /* 悬停颜色 */
        }

        .text-area a {
            color: #5da5a7;
            /* 和导航栏同色系但不同颜色 */
            font-weight: bolder;
            /* 可选：加粗 */
        }

        .text-area a:hover {
            color: #447278;
            /* 悬停颜色 */
        }

        /* 修改后的頁腳樣式 */
        footer {
            width: 100%;
            height: auto;
            /* 改为自动高度 */
            padding: 10px 0;
            /* 增加上下内边距 */
            background-color: #5da5a7;
            display: flex;
            flex-direction: column;
            /* 改为垂直排列 */
            justify-content: center;
            align-items: center;
            font-size: 14px;
            color: white;
            position: relative;
            bottom: 0;
            z-index: 1;
        }

        .footer-line {
            margin: 2px 0;
            /* 行间距 */
            text-align: center;
            width: 100%;
        }

        #back-to-top {
    display: none;
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 99;
    border: none;
    outline: none;
    background-color: transparent;
    cursor: pointer;
    padding: 0;
    width: 50px;
    height: 50px;
    filter: drop-shadow(0 2px 5px rgba(0, 0, 0, 0.3)); /* 添加阴影效果 */
    transition: all 0.3s ease; /* 添加过渡效果使交互更平滑 */
}

#back-to-top:hover {
    transform: scale(1.1);
    filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.4)); /* 悬浮时阴影更深更扩散 */
}

#back-to-top img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 50%;
    background-color: white; /* 只在图片区域添加白色背景 */
}

        /* 移除媒体查询中的 max-width 限制 */
        @media (max-width: 480px) {
            #back-to-top {
                width: 50px;
                /* 保持相同大小 */
                height: 50px;
            }
        }