.gallery { display: flex; align-items:center;justify-content: center; max-width: 100% !important; }
.gallery figure { width: 300px; margin: 10px; }
.gallery img { width: 100%;height: auto;box-sizing: border-box; padding: 10px; }

@media (max-width:800px){
  .gallery { display: block; text-align: center; }
  .gallery figure { width: calc( 100% - 20px); }
}