Darkening an image with :hover

by Sreekesh S K

HTML

<div class="plsRotate">
<ul>
  <li class="firstUnda"></li>
  <li  class="secondUnda"></li>
</ul> 
</div>

CSS

.plsRotate {
    -ms-transform: rotate(-90deg); /* IE 9 */
    -webkit-transform: rotate(-90deg); /* Chrome, Safari, Opera */
    transform: rotate(-90deg);
        position: absolute;
    top: 40px;
    left: -30px;
  
}
li {
  width: .8em;
  height: .8em;
  text-align: center;
  line-height: 1em;
  border-radius: 1em;
  background: dodgerblue;
  margin: 0 1em;
  display: inline-block;
  color: white;
  position: relative;

}

li::before{
  content: '';
  position: absolute;
  top: .3em;
  left: -2.5em;
  width: 3em;
  height: .2em;
  background: #BDBDBD;
  z-index: -1;
}


li:first-child::before {
  display: none;
}

.firstUnda {
  background: black;
  border:.2em solid #BDBDBD ;
  
}
.secondUnda {
  background: black;
  border:.2em solid #BDBDBD ;
}