.containera{
    max-width:1400px;margin:0 auto;

}
      

        /* 单条内容模块 */
        .content-item {
            background: #fff;
            border-radius: 12px;
            padding: 40px;
            margin-bottom: 50px;
            box-shadow:0 4px 20px rgba(180,0,0,0.08); /* 同步调整阴影色值 */
            transition: all 0.3s ease;
        }

        .content-item:hover {
            transform: translateY(-5px);
           box-shadow:0 4px 20px rgba(180,0,0,0.08); /* 同步调整阴影色值 */
        }

        /* 序号标题 */
        .item-title {
            font-size: 22px;
            color: #b40000;
            font-weight: bold;
            margin-bottom: 25px;
            display: flex;
            align-items: center;
        }

        .item-title span {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 32px;
            height: 32px;
            background-color: #b40000;
            color: #fff;
            border-radius: 50%;
            margin-right: 12px;
            font-size: 16px;
        }

        /* 文案内容 */
        .item-desc {
            font-size: 16px;
            color: #444;
            margin-bottom: 30px;
            text-align: justify;
        }

        /* 多图布局 */
        .image-group {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 20px;
            margin-top: 20px;
        }

        .image-group img {
            width: 100%;
            height: 290px;
            object-fit: cover;
            border-radius: 8px;
            box-shadow: 0 3px 10px rgba(0,0,0,0.1);
            transition: 0.3s;
        }

        .image-group img:hover {
            transform: scale(1.03);
        }

        /* 底部 */
        .footer {
            text-align: center;
            padding: 30px;
            color: #666;
            background: #fff;
            margin-top: 30px;
        }

        /* 响应式适配 */
        @media (max-width: 768px) {
            .containera{
                margin: 0 10px;
            }
            .main-title {
                font-size: 26px;
            }
            .content-item {
                padding: 25px;
            }
            .item-title {
                font-size: 19px;
            }
        }