Banner in front of iframe demo

HTML

<div class="relative-wrapper">
  <!-- simulating iframe -->
  <div class="iframe"></div>
  
  <div class="banner">
    <!-- simulatin image -->
    <img class="some-image" />
  </div>
</div>

CSS

.relative-wrapper {
  position: relative;
}

.iframe {
  /* simulating iframe */
  width: 500px;
  height: 300px;
  background-color: black;
}

.banner {
  /* banner positioning */
  position: absolute;
  top: 50%;
  left: 40%;
}

.some-image {
  /* simulating image size */
  width: 200px;
  height: 50px;
  background-color: red;
}