效果：
HTML代码：
XML/HTML Code复制内容到剪贴板 <div class="box shadow"></div>CSS代码：
CSS Code复制内容到剪贴板 .box { width: 300px; height: 100px; background: #ccc; border-radius: 10px; margin: 10px; } .shadow { position: relative; max-width: 270px; box-shadow: 0px 1px 4px rgba(0,0,0,0.3),/* 外阴影*/ 0px 0px 20px rgba(0,0,0,0.1) inset;/*内阴影*/ } .shadow::before, .shadow::after { content:""; position:absolute; z-index:-1; } .shadow::before, .shadow::after { content:""; position:absolute; z-index:-1; bottombottom:15px; left:10px; width:50%; height:20%; } .shadow::before, .shadow::after { content:""; position:absolute; z-index:-1; bottombottom:15px; left:10px; width:50%; height:20%; box-shadow:0 15px 10px rgba(0, 0, 0, 0.7); transform:rotate(-3deg); } .shadow::after{ rightright:10px; left:auto; transform:rotate(3deg); }伪元素before和after意思是在被选元素的内容前或后 插入内容
