Why does the background-color of .a does not change when I hover? .b?
CSS
.a {
color: red;
}
.b {
color: orange;
}
.b:hover .a {
background-color: blue;
}
HTML
<div id="wrap">
<div class="a">AAAA
<div class ="b">BBBB</div>
</div>
</div>