.case .case_con .case_txt{
padding: 40px;
float: left;
width: 494px;
height: 402px;
background-color: #f2f2f2;
align-items: center;
justify-content: center;
display: flex;
}
<div class="case_txt" style="">
<div>
<p class="title">达标排放，异味净化</p>
<p class="txt"><span>达标排放：</span>按照环保要求设计方案，实现废气达标排放</p>
<p class="txt"><span>异味净化：</span>净化废气中的刺激性异味</p>
<p class="txt"><span>节能降耗：</span>风机选型精确按需匹配、静电模块单位功率<br> 低，平均节能20%</p>
</div>
</div>
