我有一个带有一些div的容器，该容器使3个框水平显示。
我正在尝试使div在手机和平板电脑上垂直（居中）堆叠。我遇到的问题是我使用的媒体查询和样式似乎无法正常工作。
<div class="container-2">
<div class="box">
<div class="icon"><i class="fa fa-compact-disc" aria-hidden="true"></i>
</div>
<div class="content">
<h3>Artists</h3>
<p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Odit, nam quae quasi enim, praesentium, deserunt voluptatibus dolores laboriosam ex odio quod aperiam ipsa aspernatur soluta suscipit et iusto quas impedit.</p>
</div>
</div>
<div class="box">
<div class="icon"><i class="fa fa-calendar-alt" aria-hidden="true"></i>
</div>
<div class="content">
<h3>Calendar</h3>
<p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Odit, nam quae quasi enim, praesentium, deserunt voluptatibus dolores laboriosam ex odio quod aperiam …