/* Pixel-perfect stack, full-width images, with invisible clickable hotspots.
   Added back-to-top button. */

:root{
  --bg: #ffffff;
}

*{box-sizing:border-box; margin:0; padding:0;}
html,body{height:100%; background:var(--bg); font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial; color:#111; scroll-behavior:smooth;}

.pdf-stack{display:flex; flex-direction:column; align-items:center; gap:0; width:100%;}
.pdf-page{width:100%; display:flex; justify-content:center; background:var(--bg);}
.pdf-page img{width:100%; height:auto; display:block;}

/* Wrap to position hotspots over the image proportionally */
.page-wrap{position:relative; width:100%;}
.hotspots{position:absolute; inset:0;}

/* Invisible clickable areas */
.hotspot{
  position:absolute;
  display:block;
  background:transparent;
  text-decoration:none;
  cursor:pointer;
}

/* Footer */
.site-footer{padding:2rem; text-align:center; color:#666; font-size:0.9rem;}

/* Back to top button */
.back-to-top{
  position:fixed;
  bottom:20px;
  right:20px;
  background:#ff66a3; /* cute pink */
  color:#fff;
  padding:10px 14px;
  border-radius:50px;
  font-size:14px;
  text-decoration:none;
  box-shadow:0 2px 5px rgba(0,0,0,0.2);
  transition:background 0.2s;
}
.back-to-top:hover{
  background:#ff3385;
}