如何将一个div覆盖在另一个div上

I need assistance with overlaying one individual div over another individual div.

My code looks like this:

<div class="navi"></div>
<div id="infoi">
    <img src="info_icon2.png" height="20" width="32"/>
</div>

Unfortunately I cannot nest the div#infoi or the img, inside the first div.navi.

It has to be two separate divs as shown, but I need to know how I could place the div#infoi over the div.navi and to the right most side and centered on top of the div.navi.

解决方案

#container {
  width: 100px;
  height: 100px;
  position: relative;
}
#navi,
#infoi {
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
}
#infoi {
  z-index: 10;
}

<div id="container">
  <div id="navi">a</div>
  <div id="infoi">
    <img src="https://appharbor.com/assets/images/stackoverflow-logo.png" height="20" width="32" />b
  </div>
</div>

I would suggest learning about position: relative and child elements with position: absolute.