CCS设置第一个li的元素与其他li样式不同

 <div class="ly-content-list">
             <ul>
                 <li>
                     <div class="title">
                         <p>HBTMNO1234567890</p>
                         <span></span>
                     </div>
                     <div class="content">
                         <p>账号：22</p>
                         <p>姓名：测试22</p>
                         <p>领用时间：2019-3-24 19:32:45</p>
                         <p>领用统计</p>
                         <p>GS3202:20000台</p>
                         <p>G-140W-MD:20000台</p>
                         <p>G-140W-MD:20000台</p>

                         <div class="scan-btn">
                             <button class="detail-btn">查看设备详情</button>
                             <button >确认</button>
                         </div>
                     </div>
                 </li>
                 <li>
                     <div class="title">
                         <p>HBTMNO1234567890</p>
                         <span></span>
                     </div>
                     <div class="content">
                         <p>账号：ceshi</p>
                         <p>姓名：测试</p>
                         <p>领用时间：2019-3-24 19:32:45</p>
                         <p>领用统计</p>
                         <p>GS3202:20000台</p>
                         <p>G-140W-MD:20000台</p>
                         <p>G-140W-MD:20000台</p>

                         <div class="scan-btn">
                             <button class="detail-btn">查看设备详情</button>
                             <button >确认</button>
                         </div>
                     </div>
                 </li>

             </ul>
         </div>

CSS代码：

 .ly-content-list ul li:first-child .content {
             position: relative;
             color: #999999;
             font-size: .2rem;
             line-height: .4rem;
             min-height: 1rem;
             overflow: hidden;
             padding: 0 .1rem;
             display: "";
 }
 .ly-content-list ul li:not(:first-child) .content {
     position: relative;
     color: #999999;
     font-size: .2rem;
     line-height: .4rem;
     min-height: 1rem;
     overflow: hidden;
     padding: 0 .1rem;
     display: none;
 }

li:first-child：第一个li元素

li:not(:first-child)：除了第一个li的其他元素