header {
            background-color: #007bff;
            color: white;
            padding: 20px;
            text-align: center;
            box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
        }
        header img {
            max-width: 270px; /* Logo 最大宽度 */
            height: auto;
            margin-bottom: 10px;
        }
        main {
            padding: 20px;
            max-width: 1200px;
            margin: auto;
        }
        .speed-test-links a {
            display: block;
            margin: 5px 0;
            color: #007bff;
            text-decoration: none;
        }
        .advertisement {
            text-align: center;
            margin: 10px 0;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
        }
        .advertisement img {
            width: 100%;
            height: auto;
            transition: transform 0.3s;
            loading: lazy; /* 懒加载 */
        }
        .advertisement img:hover {
            transform: scale(1.05);
        }
        .side-advertisements {
            display: flex;
            justify-content: space-between;
            margin: 10px 0;
            flex-wrap: wrap;
        }
        .side-ad {
            flex: 1 1 300px;
            margin: 10px;
            text-align: center;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
        }
        .side-ad img {
            width: 100%;
            height: auto;
            transition: transform 0.3s;
            loading: lazy; /* 懒加载 */
        }
        .side-ad img:hover {
            transform: scale(1.05);
        }
        .text-ads {
            display: flex;
            justify-content: space-between;
            margin: 20px 0;
            flex-wrap: wrap;
        }
        .text-ad {
            flex: 1 1 calc(25% - 20px); /* 四列布局 */
            margin: 10px;
            padding: 15px;
            background-color: #e7e7e7;
            border-radius: 10px;
            text-align: center;
            box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
            transition: background-color 0.3s;
        }
        .text-ad a {
            color: #007bff;
            text-decoration: none;
            font-weight: bold;
        }
        .text-ad a:hover {
            text-decoration: underline;
            color: #0056b3;
        }
        .speed-test-container {
            display: flex;
            justify-content: space-between;
            margin: 20px 0;
            flex-wrap: wrap;
        }
        .speed-test-links {
            flex: 1 1 300px;
            margin: 10px;
            padding: 15px;
            background-color: #e7e7e7;
            border-radius: 10px;
            box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
        }
        .ad-stats {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            margin: 20px auto;
            padding: 15px;
            background-color: #e7e7e7;
            border-radius: 10px;
            box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
            text-align: center;
        }
        .stat-item {
            flex: 1 1 150px;
            margin: 10px;
        }
        .contact-info {
            text-align: center;
            margin: 20px 0;
            font-size: 16px;
        }
        footer {
            text-align: center;
            padding: 15px;
            background-color: #007bff;
            color: white;
            position: relative;
            bottom: 0;
            width: 100%;
            box-shadow: 0 -2px 5px rgba(0, 0, 0, 0.2);
        }
        @media (max-width: 600px) {
            header, footer {
                padding: 10px;
            }
            main {
                padding: 10px;
            }
            .advertisement, .side-ad, .speed-test-links, .text-ad, .ad-stats {
                font-size: 14px;
                flex: 1 0 100%;
                margin: 5px 0;
            }
            .text-ads {
                flex-direction: column;
            }
            .side-advertisements {
                flex-direction: column;
            }
        }