css 判断浏览器的方法：

@media screen and (-webkit-min-device-pixel-ratio:0) {
.fileinput {
margin-left: -30%;
}
}

@-moz-document url-prefix() {
.fileinput {
margin-left: -26%;
}
}

<div class="input input-w1">
<div class="inputFileBox">
<form id="importform" action="/microMaster/channelcompany/channelCompany/onlineAdditionUploadTemplet" method="post" enctype="multipart/form-data">
<label class="label label-w6" for="importexcels">浏览</label>
<input class="fileinput" cursor: pointer;width:252px;" name="importexcel" type="file" id="importexcels"/>
</form>
</div>
</div>