CSS: Image Fade In, Fade Out

.image-fade-in-out-container {
  position: relative;
}

.image-fade-in-out {
  opacity: 0.0;
  transition: opacity 1s ease-in-out;
}

.image-fade-in-out:hover {
  opacity: 1.0;
  transition: opacity .55s ease-in-out;
}

.image-fade-in-out-mask {
  position: absolute;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.8);
  display: flex;
  justify-content: center;
  align-items: center;
}

<div class="image-fade-in-out-container">
  <a href="[url]" class="image-fade-in-out">
    <div class="image-fade-in-out-mask">
      <!-- hover elements -->
    </div>
    <img src="[path-to-image]" class="width-100">
  </a>
</div>

Passe o mouse por cima das imagens.

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