.lightbox{
  position:fixed; inset:0; background:rgba(0,0,0,.9);
  display:none; align-items:center; justify-content:space-between; padding:20px; z-index:1200
}
.lightbox.show{display:flex}
.lb-stage{flex:1; display:grid; place-items:center; position:relative; margin:0 12px}
.lb-image{max-width:100%; max-height:80vh; border-radius:12px; box-shadow:0 10px 40px rgba(0,0,0,.5); transition:transform .2s ease}
.lb-counter{position:absolute; left:12px; bottom:12px; color:#fff; background:rgba(0,0,0,.4); padding:.