css里的id选择器在es6里为啥不生效，只能用标签选择和类选择

<!--右侧生活区-->

<div class="live-center">

<a href="#" class="menu1" id="live">

<i class="glyphicon glyphicon-plus"></i>

<span class="span-live">Live</span>

</a>

<a href="#" class="menu1" id="book-store">

<i class="glyphicon glyphicon-pencil"></i>

<span class="span-book">书店</span>

</a>

<a href="#" class="menu1" id="yuanzhuo">

<i class="glyphicon glyphicon-ok"></i>

<span class="span-yuanzhuo">圆桌</span>

</a>

<a href="#" class="menu1" id="zhuanlan">

<i class="glyphicon glyphicon-play-circle"></i>

<span class="span-zhuanlan">专栏</span>

</a>

<a href="#" class="menu1" id="fee">

<i class="glyphicon glyphicon-adjust"></i>

<span class="span-fee">付费咨询</span>

</a>

<a href="#" class="menu1" id="baike">

<i class="glyphicon glyphicon-file"></i>

<span class="span-baike">百科</span>

</a>  

</div>

<!--右侧生活区-->

css里的id选择器在es6里为啥不生效，

#live{

text-decoration: none;

}