/* Monochrome Gallery — refined masonry, mobile-ready, consistent link styling */
:root{
  --bg:#fff; --fg:#000;
  --gap:16px;
  --container: 1200px; /* site max width */
  --row: 8px;          /* masonry row height */
  --cols: 5;           /* max columns on desktop */
  --tile-b: 1px;       /* tile border width */
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0; background:var(--bg); color:var(--fg);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial;
  line-height:1.45; letter-spacing:.01em;
  -webkit-text-size-adjust: 100%;
}

.container{max-width:var(--container); margin:0 auto; padding:0 20px}

.site-header,.site-footer{
  display:flex; align-items:center; justify-content:space-between;
  padding:20px 0; border-bottom:1px solid #000;
}
.site-footer{ border-top:1px solid #000; border-bottom:none; justify-content:center; gap:1rem; flex-wrap:wrap; }

.site-title{ margin:0; font-weight:800; text-transform:uppercase; letter-spacing:.06em; }

.btn{
  color:#fff; background:#000; text-decoration:none; border:1px solid #000;
  padding:.6rem .9rem; display:inline-block; line-height:1; white-space:nowrap;
  -webkit-tap-highlight-color: transparent;
}
.btn.ghost{ color:#000; background:#fff }
.btn:focus,.btn:hover{ outline:2px solid #000; outline-offset:2px }
.btn:active{ transform: translateY(1px) }

/* Header responsive: stack actions on small screens */
@media (max-width: 520px){
  .site-header{ flex-direction:column; align-items:stretch; gap:.75rem }
  .site-nav{ display:grid; grid-template-columns:1fr 1fr; gap:.5rem }
  .site-nav .btn{ text-align:center; width:100% }
}

main{ padding:24px 0 }

/* Masonry Gallery (pure CSS grid + JS for row spans) */
.gallery{
  display:grid;
  grid-template-columns: repeat(2, 1fr);
  gap:var(--gap);
  align-items:start;
  grid-auto-rows: var(--row); /* base row for masonry */
  margin: 0 auto;
  -webkit-tap-highlight-color: transparent;
}
@media (min-width:640px){ .gallery{ grid-template-columns: repeat(3, 1fr); } }
@media (min-width:900px){ .gallery{ grid-template-columns: repeat(4, 1fr); } }
@media (min-width:1100px){ .gallery{ grid-template-columns: repeat(var(--cols), 1fr); } }

.card{ margin:0; display:block }
.thumb{
  position:relative; display:block; width:100%;
  border:var(--tile-b) solid #000; background:#fff; overflow:hidden;
  transform:translateZ(0);
  -webkit-tap-highlight-color: transparent;
}
.thumb img{
  display:block; width:100%; height:auto; object-fit:contain; background:#fff;
  transform: scale(1); transition: transform .18s linear;
}
/* Dark scrim over thumbnails */
.thumb .scrim{
  content:""; position:absolute; inset:0; background:rgba(0,0,0,.15);
  transition: opacity .18s linear; opacity:1;
}
/* Hover & touch-active zoom */
.thumb:hover img, .thumb:focus img, .thumb.active img{ transform: scale(1.03) }
.thumb:hover .scrim, .thumb:focus .scrim, .thumb.active .scrim{ opacity:.05 }
.thumb:focus{ outline:2px solid #000; outline-offset:2px }

.caption{ display:none } /* purely visual grid; captions hidden in tiles */

/* Lightbox */
.lightbox[hidden]{ display:none }
.lightbox{
  position:fixed; inset:0; background:#000; display:grid; place-items:center;
}
.lb-stage{ max-width:min(96vw,1600px); max-height:90vh; display:grid; gap:.5rem; justify-items:center; padding:0 10px }
#lb-image{ max-width:100%; max-height:80vh; border:1px solid #fff; background:#000 }
.lb-caption{ color:#fff; text-align:center; font-size:.95rem; max-width:90vw; word-break:break-word }

/* Lightbox controls (consistent on mobile) */
.lb-btn{
  position:fixed; background:transparent; color:#fff !important; border:1px solid #fff;
  padding:.35rem .6rem; cursor:pointer; font-size:1.5rem; line-height:1; text-decoration:none;
  -webkit-tap-highlight-color: transparent;
}
.lb-btn.close{ top:1rem; right:1rem }
.lb-btn.prev,.lb-btn.next{
  top:50%; transform:translateY(-50%); width:3rem; height:3rem; display:grid; place-items:center; font-size:2rem;
}
.lb-btn.prev{ left:1rem } .lb-btn.next{ right:1rem }
.lb-btn.download{ bottom:1rem; right:1rem; top:auto; font-size:1.25rem }
.lb-btn:focus,.lb-btn:hover{ outline:2px solid #fff; outline-offset:2px }
.lb-btn:active{ transform: translateY(1px) }

/* Make controls a bit larger on very small phones */
@media (max-width:420px){
  .lb-btn.prev,.lb-btn.next{ width:2.6rem; height:2.6rem; font-size:1.8rem }
  .lb-btn.download{ font-size:1.1rem }
}