mui-checkbox为什么来来去去都是圆的啊？

<li class="mui-table-view-cell">
<div class="mui-checkbox mui-left mui-pull-left">
<label>全选</label>
<input name="checkbox1" type="checkbox" />
</div>
<div class="mui-pull-right">
<button class="mui-btn mui-btn-primary" type="button" onclick="return false;">上传</button>&nbsp;&nbsp;
</div>
</li>

------------------ css
.mui-checkbox input[type=checkbox]:before {
content: '\e413';
}
.mui-checkbox input[type=checkbox]:checked:before {
content: '\e443';
}
.mui-checkbox.mui-left input[type=checkbox]{
left: 0px;
}
.mui-checkbox.mui-left label, .mui-radio.mui-left label {
margin-top: 10px;
padding-right: 15px;
padding-left: 30px;
}
.mui-table-view-cell {
position: relative;
overflow: hidden;
padding: 11px 15px;
-webkit-touch-callout: none;
}

有没有正方形的？

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