css-按钮中有图片和文字，怎么才能让文字和图片都中？？

<div class="btn1 trans" >

<img src="../../images/img/add.png"/>

<div class="tip">回答问题</div>

</div>

 

css:(less写法，可以写成css的也行)

.btn1{

width:105px;

height:36px;

background:#FB452F;

border-radius:2px;

display: inline-block;

margin-right: 14px;

color:#fff;

cursor: pointer;

img{

vertical-align: top;

margin-top: 12px;

margin-left: 10px;

margin-right: 5px;

width: 12px;

height: 12px;

 

}

.tip{

display: inline-block;

padding-top: 8px;

}

&:hover{

background:#FF5844;

color:#fff;

}

}