一个外层div内嵌2个div,左边div宽度定死，右边自适应宽度，右边的宽度要填充满
<li class="law-case-detail">
<div style="70px;">案情简介</div>
<textarea class="comment" placeholder="描述信息..."></textarea>
</li>
.law-case-detail{display: box!important;display:-moz-box!important;display: -webkit-box!important; 100%;box-sizing:border-box;}
.comment {background: #f8f8f8;padding: 5px;border: 1px solid #EBEBEB;border-radius: 3px;height:140px;display:block;box-flex:1.0;-moz-box-flex:1.0;-webkit-box-flex:1.0;}
要点：display:box; box-sizing:border-box; box-flex:1.0; display:block;