@media only screen and (min-width : 768px) {
  :root {
    --width: 750px;
  }

  .main { 
    max-width: var(--width);
  }
  
  .main-header { 
    max-width: var(--width);
  }
  
  .main-footer { 
    max-width: var(--width);
  }
  
  .gallery-list {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
  }

  .image-photo.portrait {
    width: 600px;
    height: auto;
    margin: 0 auto;
    display: block;
  }
}