<div class="container">

  <div class="gallery-wrap">
    <div class="item item-1"></div>
    <div class="item item-2"></div>
    <div class="item item-3"></div>
  </div>
 </div>
  </a>
html,body{
  width: 100%;
  height: 100%;
}

.container{
  padding-top: 45px;
  margin: auto;
  width: 850px;
}


.gallery-wrap {
  display: flex;
  flex-direction: row;
  width: 100%;
  height: 70vh;
}

.item {
  flex: 1;
  height: 100%;
  background-position: center;
  background-size: cover;
  background-repeat: none;
  transition: flex 0.8s ease;
  
  &:hover{
    flex: 7;
  }
}

.item-1 { 
  background-image: url('https://static.tildacdn.com/tild6365-3436-4530-a665-313331306634/3.jpg');
}

.item-2 { 
  background-image: url('https://static.tildacdn.com/tild3230-3965-4866-b433-613939623832/5.jpg');
}

.item-3 { 
  background-image: url('https://static.tildacdn.com/tild3737-6533-4165-b835-383636663337/4.jpg');
}



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