<a class="c-preview">
  <div class="c-preview__img"></div>
  <h2 class="c-preview__title">foo bar</h2>
</a>

body {
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

.c-preview {
  background: #000;
  background: linear-gradient(135deg, rgba(0,0,0,1) 0%, rgba(0,0,0,1) 13%, rgba(0,0,0,1) 32%, rgba(116,132,190,1) 47%, rgba(208,133,109,1) 80%, rgba(69,252,212,1) 94%);
  background-size: 400% 400%;
  background-repeat: no-repeat;
  display: flex;
  width: 500px;
  height: 500px;
  max-width: 100vw;
  max-height: 100vh;
  justify-content: center;
  align-items: center;
  color: #fff;
  position: relative;
  cursor: pointer;
  transition: .5s all;
}
.c-preview__img {
  position: absolute;
  left: 0;
  top: 0;
  background: #000 url(https://picsum.photos/600/400) no-repeat center center;
  background-size: cover;
  width: 100%;
  height: 100%;
  z-index: 1;
  opacity: .5;
  
}
.c-preview__title {
  position: relative;
  z-index: 10;
  text-transform: uppercase;
  letter-spacing: .05em;
}
.c-preview:hover {
  background-position: 100% 100%;
}