* { margin: 0; padding: 0; }
        html, body { max-width: 461px; height: 100%; margin: 0 auto; }
        .img-box { width: 100%; }
        .img-item { 
            position: relative; /* 关键：为绝对定位的子元素提供参照 */
            margin-bottom: 10px;
        }
        .img, .img-ai {
            width: 100%;
            height: auto;
            cursor: pointer;
            transition: opacity 0.5s ease; /* 平滑过渡 */
        }
        .img-ai {
            position: absolute; /* 叠加在原始图片上 */
            top: 0;
            left: 0;
            opacity: 0; /* 初始隐藏 */
        }
        .btn-img {
            width: 50%;
            position: absolute;
            bottom: 50px;
            left: 25%;
        }
        .img-item.active .img { opacity: 0; }
        .img-item.active .img-ai { opacity: 1; }
        .img-item.active .btn-img { opacity: 0; }
        .text-box {
            width: 100%;
            height: auto;
        }
        .title {
            width: 100%;
            line-height: 2;
            font-size: 22px;
            font-weight: bold;
            color: #121212;
        }
        .summary {
            width: 100%;
            height: auto;
            text-align: center;
            line-height: 2;
            font-size: 17px;
            margin-bottom: 20px;
        }
        .summary p {
            color: #254ba2;
            font-weight: bold;
        }