/* ---------- layout / thumbnails ---------- */
body{
  margin:0;
  font-family:Arial,Helvetica,sans-serif;
  padding:1rem;
}

/* will be “auto-fill” by default or 2-col when forced */
.grid{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(320px,1fr));
  gap:1rem;
}

.item img,
.item video{
  width:100%;
  height:auto;
  border:1px solid #ccc;
  box-sizing:border-box;
  cursor:pointer;
}

.prompt{
  width:100%;
  height:120px;
  margin-top:6px;
  overflow:auto;
  resize:vertical;
  box-sizing:border-box;
}

/* ---------- light-box ---------- */
#overlay{
  display:none;
  position:fixed;
  inset:0;
  background:rgba(0,0,0,.9);
  z-index:9999;
  flex-direction:column;
  align-items:center;
  justify-content:center;
  overflow:auto;
  overscroll-behavior:contain;   /* stop background scrolling */
}

#overlay.scrollY{              /* vertical overflow when zoomed */
  justify-content:flex-start;
}

#overlay img{
  max-width:90vw;
  max-height:90vh;
  cursor:zoom-in;
}

#overlay img.zoomed{
  max-width:none;
  max-height:none;
  cursor:zoom-out;
}

#overlay video{
  max-width:90vw;
  max-height:90vh;
  cursor:default;              /* videos don’t zoom */
}

#caption{
  color:#fff;
  margin:1rem auto 0 auto;
  text-align:center;
  font-size:1rem;
  padding:0 1rem;
  max-width:90vw;
}