/* ==========================================================================
   BOOK-FLIP & 3D HARDCOVER SIMULATION STYLES
   ========================================================================== */

/* Realistic 3D Tilt container */
.book-stage-3d {
  perspective: 1500px;
}

.book-3d-wrapper {
  position: relative;
  width: 320px;
  height: 480px;
  transform-style: preserve-3d;
  transition: transform 0.1s ease-out;
}

/* Front Cover */
.book-cover-front {
  position: absolute;
  inset: 0;
  border-radius: 4px 16px 16px 4px;
  overflow: hidden;
  box-shadow: 
    inset 4px 0 10px rgba(0, 0, 0, 0.4),
    inset -2px 0 6px rgba(255, 255, 255, 0.25),
    -15px 20px 40px rgba(0, 0, 0, 0.85);
  background: #0d0e12;
  transform: translateZ(20px);
}

.book-cover-front img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* Spine */
.book-spine-3d {
  position: absolute;
  top: 0;
  left: 0;
  width: 40px;
  height: 100%;
  transform-origin: left;
  transform: rotateY(-90deg) translateZ(0px);
  background: linear-gradient(90deg, #181512 0%, #30261f 50%, #151310 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.8);
  border-left: 1px solid rgba(255, 255, 255, 0.15);
}

.spine-text {
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  font-family: 'Playfair Display', Georgia, serif;
  font-size: 0.85rem;
  font-weight: 700;
  color: #edd79d;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

/* Thick Paper block */
.book-pages-3d {
  position: absolute;
  top: 6px;
  right: -24px;
  width: 24px;
  height: calc(100% - 12px);
  transform-origin: left;
  transform: rotateY(90deg);
  background: repeating-linear-gradient(
    90deg,
    #f7f0e3 0px,
    #eee3cb 1px,
    #e5d9bf 2px,
    #f7f0e3 3px
  );
  box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.35);
  border-radius: 0 4px 4px 0;
}

/* Gloss reflection on cover */
.book-cover-front::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.2) 0%,
    rgba(255, 255, 255, 0.05) 30%,
    transparent 60%
  );
  pointer-events: none;
}

/* Page flip transition styles */
.flip-animating {
  animation: pageTurnCurl 0.45s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes pageTurnCurl {
  0% {
    transform: perspective(1000px) rotateY(0deg);
    opacity: 1;
  }
  50% {
    transform: perspective(1000px) rotateY(-8deg) scale(0.98);
    opacity: 0.6;
    filter: brightness(0.9);
  }
  100% {
    transform: perspective(1000px) rotateY(0deg) scale(1);
    opacity: 1;
    filter: brightness(1);
  }
}

/* Tactile paper texture on reader container */
.reader-book-container::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle at 50% 50%, transparent 60%, rgba(0, 0, 0, 0.03) 100%);
  pointer-events: none;
}

/* Book reader gutter shadow (center crease) */
.reader-book-container::after {
  content: '';
  position: absolute;
  top: 0;
  left: 28px;
  bottom: 0;
  width: 18px;
  background: linear-gradient(90deg, rgba(0, 0, 0, 0.08) 0%, transparent 100%);
  pointer-events: none;
}