:hover style on div with an image that doesnt trigger

Question

I've been trying to make a overlay hover effect on a website with pure css

                       <div class="col-md-4 port-show">
                            <img class="img-responsive" alt="" src="">
                            <h2 class=""></h2>
                            <ul>
                                <li></li>
                                <li></li>
                            </ul>
                        </div>

But I've run into the problem when I hover over the img that the overlay will not trigger. I know I have to do it differently, but just don't now how. CSS:

:hover:after{
        content: "";
        z-index: 10;
        display: block;
        position: absolute;
        height: 100%;
        top: 0;
        left: 0;
        right: 0;
        background: red;
        border-radius: 6px;
        border-color: transparent;
    }

Answer 1

You can look here. Maybe this solution will be helpfull for you.

http://codepen.io/anon/pen/VKmxZw

.img-holder {
  position: relative;
  z-index: 1;
  display: block;
  width: 350px;
}
.img-holder img {
  display: block;
  width: 100%;
}
.img-holder:after {
  content: " ";
  width: 100%;
  height: 100%;
  background-color: red;
  z-index: 2;
  left: 0;
  top: 0;
  position: absolute;
  opacity: 0;
}
.img-holder:hover:after {
  opacity: 1;
}

<div class="col-md-4 port-show">
  <span class="img-holder">
    <img src="http://placehold.it/350x150" />
  </span>
  <h2 class=""></h2>
  <ul>
    <li></li>
    <li></li>
  </ul>
</div>