<div class="box">
  <img src="https://images.unsplash.com/photo-1518489913881-199b7c7a081d?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1774&q=80" alt="">
  <img src="https://images.unsplash.com/photo-1484446991649-77f7fbd73f1f?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1770&q=80" alt="">
  <img src="https://images.unsplash.com/photo-1512005286309-e5b890ca36b6?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=2064&q=80" alt="">
</div>

*{
  margin: 0;
  padding: 0;
}

body {
  width: 100vw;
  height: 100vh;
  overflow: hidden;
}
.box{
  // Key CSS
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  display: flex;
  overflow-x: scroll;
}
.box img{
  height: 100vh;
  min-width: 100vw;
  // Key CSS
  scroll-snap-align: start;
}