body{
  margin:0;
  font-family: Arial, sans-serif;
  background:white;
  overflow-x:hidden;
}

.navbar-premium{
  background:rgba(0,0,0,.45);
  backdrop-filter:blur(10px);
  z-index:20;
}

.navbar-premium .nav-link,
.navbar-premium .navbar-brand{
  color:#fff !important;
}

.navbar-premium .nav-link:hover{
  color:#d4af37 !important;
}

.book-section{
  min-height:100vh;
  display:flex;
  flex-direction:column;
  justify-content:center;
  align-items:center;
  padding:110px 20px 60px;
  background:linear-gradient(180deg, #111827, #000);
}

.book-frame{
  width:min(92vw, 1100px);
  height:min(72vh, 720px);
  position:relative;
  perspective:1800px;
  transform-style:preserve-3d;
}

.book-page{
  position:absolute;
  inset:0;
  opacity:0;
  transform:translateX(100%) rotateY(-90deg) scale(.96);
  transition:all .8s ease;
  border-radius:18px;
  overflow:hidden;
  background:#fff;
}

.book-page.active{
  opacity:1;
  transform:translateX(0) rotateY(0deg) scale(1);
  z-index:3;
}

.book-page.prev{
  opacity:0;
  transform:translateX(-100%) rotateY(90deg) scale(.96);
  z-index:1;
}

.book-page.next{
  opacity:0;
  transform:translateX(100%) rotateY(-90deg) scale(.96);
  z-index:1;
}

.book-image{
  width:100%;
  height:100%;
  object-fit:contain;
  display:block;
  background:#f3f3f3;
}

.btn-gold{
  background:linear-gradient(135deg, #d4af37, #f3dc88);
  color:#111827;
  font-weight:700;
  border:none;
}

.nav-item:hover{
  color:#111827;
background: linear-gradient(135deg, #8b0000, #ff4d4d);
}

.footer-premium{
  background:#111827;
  color:#e5e7eb;
  border-top:4px solid #d4af37;
}

@media (max-width: 768px){
  .book-frame{
    height:60vh;
  }
}