<section class="porto">
  <div class="content-container flex-wrapper">
    <div class="vertical-scroll-container">
      <img src="https://marianabeldi.github.io/scroll-driven-sardinas/img/porto1.svg" alt="sardinas bajo en sodio">
      <img src="https://marianabeldi.github.io/scroll-driven-sardinas/img/porto2.svg" alt="sardinas sin piel">
      <img src="https://marianabeldi.github.io/scroll-driven-sardinas/img/porto3.svg" alt="sardinas en agua">
      <img src="https://marianabeldi.github.io/scroll-driven-sardinas/img/porto4.svg" alt="sardinas al limon">
    </div>
  </div>
</section>

*, *::before, *::after { box-sizing: border-box; }
body {
  background-color: #3848a0;
  font-family: "Open Sans", arial, sans-serif, system-ui;
  margin: 0 auto;
}
.porto {
  color: #f5dbc8;
  padding: 32px;
  text-align: center;
}
h2 {
    line-height: 1;
    text-transform: uppercase;
}
.porto p {
    font-size: 1.1rem;
    font-weight: 500;
    letter-spacing: 0.03em;
    max-width: 40ch;
}
.flex-wrapper {
    align-items: center;
    display: flex;
    gap: 2rem;
}
.content-container {
    margin-inline: auto;
    width: 90vw;
}

.vertical-scroll-container {
  align-items: center;
  display: flex;
  flex-direction: column;
  flex: 1 1 50%;
  gap: 6rem 0;
  min-width: 400px;
  overflow-y: scroll;
  scrollbar-color: #3848a0 #1b2767;
  scroll-snap-type: y mandatory;  
  padding: 200px 20px;
  height: 400px;
}
.vertical-scroll-container img {
  scroll-snap-align: center;
  width: 400px;

  animation: slideInOut;
  animation-timeline: view();
}
/* old keyframes 
@keyframes slideIn {
  from {
    transform: scale(.8) translateY(100px); 
    opacity: 0;
  }
  to { 
    transform: scale(1) translateY(0); 
    opacity: 1;
  }
}
@keyframes slideOut {
  from {
    transform: scale(1) translateY(0); 
    opacity: 1;    
  }
  to { 
    transform: scale(.8) translateY(-100px); 
    opacity: 0 
  }
} */

/* NEW target range in keyframes */
@keyframes slideInOut {
  entry 0% {
    transform: scale(.8) translateY(100px); 
    opacity: 0;
  }
  entry 100% { 
    transform: scale(1) translateY(0); 
    opacity: 1;
  }
  exit 0% {
    transform: scale(1) translateY(0); 
    opacity: 1;    
  }
  exit 100% { 
    transform: scale(.8) translateY(-100px); 
    opacity: 0 
  }
}

@media screen and (max-width: 40em) {
  .vertical-scroll-container img {
    padding: 0;
    width: 300px;
  }
}