.book-single {
    padding: 120px 6vw 160px;
}

/* ===============================
   HERO
================================ */

.book-hero {
    margin-bottom: 140px;
}

.book-hero-layout {
    display: grid;
    grid-template-columns: 1fr 420px;
    gap: 80px;
    align-items: start;
}

.book-tier {
    font-size: 12px;
    letter-spacing: 0.3em;
    text-transform: uppercase;
    color: var(--gold);
    opacity: 0.85;
}

.book-title {
    font-size: 42px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    margin: 20px 0;
}

.book-author {
    font-size: 15px;
    opacity: 0.75;
}

.book-short {
    max-width: 620px;
    line-height: 1.9;
    opacity: 0.9;
}

.book-hero-image {
    position: relative;
}

.book-hero-image img {
    width: 100%;
    aspect-ratio: 1 / 1;
    object-fit: cover;
    border-radius: 26px;
    box-shadow: 0 40px 90px rgba(0,0,0,0.65);
}

.book-hero-image.soldout img {
    filter: grayscale(100%) blur(1.5px);
    opacity: 0.7;
}

.book-hero-image.soldout::after {
    content: "Sold Out";
    position: absolute;
    top: 18px;
    left: 18px;
    background: var(--color-sandstone-grey);
    color: #111;
    font-size: 13px;
    font-weight: 600;
    padding: 6px 14px;
    border-radius: 999px;
}

/* ===============================
   PURCHASE PANEL
================================ */
.book-info{
    display:flex;
    flex-direction:row;
    gap:25px;
}
.book-purchase {
    margin-bottom: 140px;
    display: flex;
    justify-content: center;
}

.book-purchase-info {
    width: 100%;
    max-width: 720px;
    display: flex;
    flex-direction: column;
    gap: 18px;
    padding: 42px 56px;
    border-radius: 22px;
    background: rgba(0,0,0,0.45);
    backdrop-filter: blur(14px);
    border: 1px solid rgba(255,255,255,0.08);
}

.price-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.price-label {
    font-size: 13px;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    opacity: 0.65;
}

.price-old {
    text-decoration: line-through;
    opacity: 0.5;
}

.price-new {
    font-size: 26px;
    font-weight: 600;
    color: var(--gold);
}

/* ===============================
   DETAILS
================================ */

.book-details {
    margin-bottom: 140px;
}

.book-details-flex {
    display: flex;
    flex-wrap: wrap;
    gap: 28px 60px;
}

.book-detail-item {
    min-width: 220px;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.book-detail-item .label {
    font-size: 12px;
    opacity: 0.6;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.book-detail-item .value {
    font-size: 15px;
}

/* ===============================
   RELATED BOOKS GRID
================================ */

.collection-items-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 22px;
}

/* ===============================
   PRODUCT CARD (AS REQUESTED)
================================ */
.related-books{
    margin-top:60px;
}

.product-card {
  position: relative;
  display: block;
  border-radius: 22px;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: 0 14px 44px rgba(0, 0, 0, 0.55);
  transition: transform 0.35s ease, box-shadow 0.35s ease;
}

.product-card::before {
  content: "";
  position: absolute;
  top: -40%;
  left: -120%;
  width: 60%;
  height: 200%;
  background: linear-gradient(
    120deg,
    transparent 0%,
    rgba(255, 255, 255, 0.08) 40%,
    rgba(255, 255, 255, 0.22) 50%,
    rgba(255, 255, 255, 0.08) 60%,
    transparent 100%
  );
  transform: rotate(12deg);
  opacity: 0;
  transition: left 0.9s ease, opacity 0.3s ease;
  pointer-events: none;
}

.product-card:hover::before {
  left: 140%;
  opacity: 1;
}

.product-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 24px 72px rgba(0, 0, 0, 0.72);
}

.product-title {
    text-align: center;
    padding: 14px;
}

.product-image {
  aspect-ratio: 1 / 1;
  overflow: hidden;
}

.product-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.product-card.soldout .product-image img {
  filter: grayscale(100%) blur(2px);
  opacity: 0.7;
}

.product-card.soldout::after {
  content: "Sold Out";
  position: absolute;
  top: 12px;
  left: 12px;
  background: var(--color-sandstone-grey);
  color: #111;
  font-size: 12px;
  font-weight: 600;
  padding: 6px 10px;
  border-radius: 999px;
}

/* ===============================
   BUTTON
================================ */

.btn {
    padding: 12px 18px;
    border-radius: 10px;
    font-size: 17px;
    font-weight: 500;
    background: linear-gradient(135deg, #c7a652, #e8d08c);
    color: #020617;
    cursor: pointer;
    transition: 0.3s ease;
    text-decoration: none;
}

.btn:hover {
    background: linear-gradient(135deg, #dabf73, #f3e2ae);
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(255, 215, 130, 0.2);
}

/* ===============================
   RESPONSIVE
================================ */

@media (max-width: 1200px) {
    .collection-items-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 820px) {
    .collection-items-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 520px) {
    .collection-items-grid {
        grid-template-columns: 1fr;
    }
}