*{box-sizing:border-box}
html,body{margin:0;min-height:100%;background:#111}
body{display:grid;place-items:center}
.full-image-publication{display:grid;place-items:center;width:100%;min-height:100vh;padding:0}
.full-image-publication img{display:block;width:auto;height:auto;max-width:100vw;max-height:100vh;object-fit:contain;background:#fff}
@page{size:A4 portrait;margin:0}
@media print{
  html,body,.full-image-publication{width:210mm;height:297mm;min-height:297mm;background:#fff}
  .full-image-publication img{width:210mm;height:297mm;max-width:none;max-height:none;object-fit:contain}
}