<div class="image"><img src="https://cdn.brcgames.ru/posts/2013/8/f0b9811c-2574-463e-a266-d8815931a6a7.jpg" alt=""></div>

body {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}
.image {
  position: relative;
  display: inline-flex;
  border-top-left-radius: 8px;
  border-top-right-radius: 8px;
  overflow: hidden;
  &:before {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    opacity: 0;
    background: linear-gradient(to bottom, rgba(0,0,0,0) 0%, rgba(0,0,0,0.4) 70%, rgba(0,0,0,1) 100%);
    transition: opacity .3s;
    will-change: opacity;
  }
  &:hover {
    &:before {
      opacity: 1;
    }
  }
}