.product-page-container {
  max-width: 1200px;
  margin: 40px auto;
  padding: 0 20px;
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 60px;
  font-family: 'Instrument Sans', sans-serif;
}
.product-gallery {
  position: relative;
}
.main-image {
  width: 100%;
  background-color: #f9f9f9;
  border-radius: 4px;
  overflow: hidden;
  position: relative;
}
.main-image img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
}
.badge-offer {
  position: absolute;
  top: 20px;
  left: 20px;
  background: black;
  color: white;
  padding: 5px 10px;
  font-size: 12px;
  font-weight: bold;
  letter-spacing: 1px;
}
.product-info {
  position: sticky;
  top: 100px; 
  height: fit-content;
}
.breadcrumbs {
  font-size: 12px;
  color: #888;
  margin-bottom: 20px;
  text-transform: uppercase;
  letter-spacing: 1px;
}
.breadcrumbs a { color: #888; text-decoration: none; }
.breadcrumbs span { color: black; font-weight: bold; }
.product-title {
  font-size: 32px;
  font-weight: 600;
  margin-bottom: 15px;
  line-height: 1.2;
}
.product-price {
  font-size: 24px;
  margin-bottom: 30px;
  display: flex;
  gap: 15px;
  align-items: center;
}
.price-regular, .price-new { font-weight: 500; color: #000; }
.price-old { text-decoration: line-through; color: #999; font-size: 18px; }
.divider { height: 1px; background: #eee; margin: 20px 0; }
.label-title {
  display: block;
  font-size: 14px;
  font-weight: bold;
  margin-bottom: 10px;
  text-transform: uppercase;
}
.sizes-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 30px;
}
.size-option input[type="radio"] { display: none; }
.size-option label {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 130px;
  height: 40px;
  border: 1px solid #ddd;
  cursor: pointer;
  font-size: 14px;
  transition: all 0.2s;
  background: white;
}
.size-option label:hover { border-color: black; }
.size-option input:checked + label {
  background-color: black;
  color: white;
  border-color: black;
}
.size-option label.disabled {
  background-color: #f5f5f5;
  color: #ccc;
  border-color: #eee;
  cursor: not-allowed;
  text-decoration: line-through;
}
.btn-add-cart {
  width: 100%;
  background-color: black;
  color: white;
  border: none;
  padding: 18px;
  font-size: 14px;
  font-weight: bold;
  letter-spacing: 1px;
  cursor: pointer;
  text-transform: uppercase;
  transition: background 0.3s;
}
.btn-add-cart:hover {
  background-color: #333;
}
.accordion-container {
  margin-top: 40px;
  border-top: 1px solid #eee;
}
details {
  border-bottom: 1px solid #eee;
  padding: 20px 0;
}
summary {
  cursor: pointer;
  font-weight: bold;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
summary::after { content: "+"; font-size: 20px; font-weight: normal; }
details[open] summary::after { content: "-"; }
.details-content {
  margin-top: 15px;
  color: #666;
  line-height: 1.6;
  font-size: 14px;
}
@media (max-width: 768px) {
  .product-page-container {
    grid-template-columns: 1fr;
    gap: 30px;
    margin-top: 20px;
  }
  .product-info {
    position: static;
  }
  .product-title { font-size: 24px; }
}
@keyframes shake {
  0% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  50% { transform: translateX(5px); }
  75% { transform: translateX(-5px); }
  100% { transform: translateX(0); }
}
.shake { animation: shake 0.3s; border: 1px solid red; padding: 5px; }