Hover Another

by Tanbi

HTML

<div id="a" class="box">1</div>
<div id="b" class="box">2</div>
<div id="c" class="box">3</div>
<div id="d" class="box">4</div>

CSS

.box{
  width: 50px;
  height: 50px;
  background-color:#aaa;
  display: inline-block;
}
#a:hover ~ #c {
    background: red;
}