/* ==========================================================
   FEATURED BOOK — PREMIUM INTERACTIVE PRESENTATION
   ========================================================== */

.enhanced-book-cover {
  position: relative !important;
  perspective: 1500px !important;
  isolation: isolate !important;
}

.book-glow {
  position: absolute;
  z-index: 0;
  top: 12%;
  left: 50%;
  width: 78%;
  height: 72%;
  transform: translateX(-50%);
  border-radius: 50%;
  pointer-events: none;
  background:
    radial-gradient(circle,
      rgba(69, 210, 255, 0.34) 0,
      rgba(62, 145, 218, 0.18) 34%,
      rgba(188, 126, 255, 0.10) 54%,
      transparent 72%);
  filter: blur(26px);
  opacity: 0.58;
  animation: featured-book-glow 4.5s ease-in-out infinite;
}

.book-flip-shell {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: 430px;
  aspect-ratio: 0.78;
  margin: 0 auto;
  perspective: 1500px;
  cursor: pointer;
  outline: none;
}

.book-flip-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 850ms cubic-bezier(.2,.75,.2,1);
  will-change: transform;
}

.book-flip-shell.is-flipped .book-flip-inner {
  transform: rotateY(180deg);
}

.book-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.book-face--front {
  transform: rotateY(0);
}

.book-face--back {
  transform: rotateY(180deg);
}

.interactive-cover {
  width: 100%;
  height: 100%;
  box-sizing: border-box;
  transition: filter 300ms ease;
  transform-style: preserve-3d;
  will-change: transform;
  box-shadow:
    0 30px 65px rgba(0,0,0,.44),
    0 0 28px rgba(57,190,255,.13);
}

.interactive-cover .cover-art,
.interactive-cover .cover-image {
  width: 100%;
  height: 100%;
}

.interactive-cover .cover-image {
  display: block;
  object-fit: contain;
  object-position: center;
}

.Out-Now-ribbon {
  position: absolute;
  z-index: 10;
  top: 24px;
  right: -12px;
  padding: 10px 20px;
  background: linear-gradient(135deg, #c49a4f, #8e6225);
  color: #10151b;
  font-family: "Space Mono", monospace;
  font-size: .68rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
  box-shadow: 0 8px 22px rgba(0,0,0,.35);
}

.Out-Now-ribbon::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: -10px;
  border-top: 10px solid #5b3a13;
  border-right: 12px solid transparent;
}

.book-back-panel {
  width: 100%;
  height: 100%;
  box-sizing: border-box;
  padding: clamp(34px, 6vw, 60px);
  display: flex;
  flex-direction: column;
  justify-content: center;
  text-align: center;
  color: #ebe2ce;
  border: 1px solid rgba(211, 171, 96, .58);
  background:
    radial-gradient(circle at 50% 34%, rgba(55,174,225,.15), transparent 34%),
    linear-gradient(160deg, #111a23, #090e14 65%, #12100d);
  box-shadow:
    inset 0 0 0 8px rgba(196,154,79,.05),
    0 30px 65px rgba(0,0,0,.44),
    0 0 34px rgba(57,190,255,.12);
}

.book-back-kicker,
.book-back-author {
  font-family: "Space Mono", monospace;
  font-size: .7rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: #c49a4f;
}

.book-back-panel h4 {
  margin: 20px 0;
  font-family: "Cormorant Garamond", serif;
  font-size: clamp(2rem, 4vw, 3.3rem);
  line-height: 1.04;
  font-weight: 500;
}

.book-back-panel p:not(.book-back-kicker):not(.book-back-author) {
  max-width: 330px;
  margin: 0 auto;
  font-size: 1rem;
  line-height: 1.75;
  opacity: .84;
}

.book-back-mark {
  margin: 28px 0 20px;
  font-size: 2rem;
  color: #62cce9;
  text-shadow: 0 0 18px rgba(98,204,233,.72);
  animation: book-back-star 2.4s ease-in-out infinite;
}

.book-flip-button {
  position: relative;
  z-index: 4;
  display: block;
  margin: 20px auto 0;
  padding: 10px 16px;
  border: 1px solid rgba(196,154,79,.52);
  background: transparent;
  color: inherit;
  font-family: "Space Mono", monospace;
  font-size: .67rem;
  letter-spacing: .12em;
  text-transform: uppercase;
  cursor: pointer;
  transition: background 220ms ease, color 220ms ease, transform 220ms ease;
}

.book-flip-button:hover {
  background: #c49a4f;
  color: #11151a;
  transform: translateY(-2px);
}

.premium-book-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.launch-button {
  cursor: default;
  opacity: .72;
  font-size: .72rem;
  white-space: nowrap;
}

@keyframes featured-book-glow {
  0%, 100% {
    opacity: .38;
    transform: translateX(-50%) scale(.96);
    filter: blur(25px);
  }
  50% {
    opacity: .78;
    transform: translateX(-50%) scale(1.07);
    filter: blur(33px);
  }
}

@keyframes book-back-star {
  0%, 100% {
    transform: scale(.9) rotate(0);
    opacity: .65;
  }
  50% {
    transform: scale(1.18) rotate(20deg);
    opacity: 1;
  }
}

@media (max-width: 700px) {
  .book-flip-shell {
    max-width: 340px;
  }

  .premium-book-actions {
    justify-content: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  .book-glow,
  .book-back-mark {
    animation: none !important;
  }

  .book-flip-inner,
  .interactive-cover {
    transition: none !important;
  }
}