html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  background: #edd4bd;
  font-family: Georgia, "Times New Roman", serif;
}
.viewer-shell {
  width: min(80vw, 1638px);
  margin: 0 auto;
  padding: 0;
  box-sizing: border-box;
}
.book-wrap {
  position: relative;
  width: 100%;
  line-height: 0;
}
.slide {
  width: 100%;
  height: auto;
  display: block;
  border: 0;
  user-select: none;
  -webkit-user-drag: none;
}
.nav {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 5;
  width: clamp(34px, 4vw, 54px);
  height: clamp(54px, 8vw, 88px);
  border: 0;
  border-radius: 999px;
  background: rgba(255,255,255,0.72);
  color: rgba(80,35,45,0.78);
  font-size: clamp(22px, 3vw, 42px);
  cursor: pointer;
  box-shadow: 0 2px 10px rgba(0,0,0,0.15);
}
.nav:hover { background: rgba(255,255,255,0.92); }
.prev { left: 1.2%; }
.next { right: 1.2%; }
.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  align-items: center;
  margin: 10px 0 12px;
  color: #6b4a4a;
  font-size: 15px;
}
.controls button {
  border: 1px solid rgba(90,60,60,0.25);
  border-radius: 999px;
  background: rgba(255,255,255,0.75);
  color: #5a3d3d;
  padding: 7px 14px;
  font-family: inherit;
  cursor: pointer;
}
.controls button:hover { background: rgba(255,255,255,0.95); }
@media (max-width: 700px) {
  .viewer-shell { padding: 0; }
  .controls { font-size: 13px; }
  .controls button { padding: 6px 10px; }
}