/* ============================================
   上海大和格栅板 - 内页专用样式补充
   ============================================ */

/* --- About Page --- */
.about-advantages {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.advantage-item {
  text-align: center;
  padding: 36px 24px;
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
  transition: var(--transition);
}

.advantage-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent);
}

.advantage-item .num {
  font-size: 48px;
  font-weight: 800;
  color: var(--primary);
  opacity: 0.15;
  line-height: 1;
  margin-bottom: 8px;
}

.advantage-item h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--text-dark);
  margin-bottom: 8px;
}

.advantage-item p {
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.7;
}

.advantage-item .advantage-img {
  width: 100%;
  height: 180px;
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 16px;
}

.advantage-item .advantage-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.5s ease;
}

.advantage-item:hover .advantage-img img {
  transform: scale(1.05);
}

/* --- Certifications --- */
.certs-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.cert-card {
  text-align: center;
  padding: 32px 20px;
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
  transition: var(--transition);
}

.cert-card:hover {
  box-shadow: var(--shadow-md);
}

.cert-card .cert-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 16px;
  background: var(--bg-light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.cert-card .cert-icon svg {
  width: 28px;
  height: 28px;
  fill: var(--accent);
}

.cert-card h4 {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-dark);
  margin-bottom: 4px;
}

.cert-card p {
  font-size: 12px;
  color: var(--text-light);
}

/* --- Product Page Specifics --- */
.product-detail-section {
  padding: 80px 0;
  background: var(--bg-light);
}

.product-detail-card {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
  overflow: hidden;
  margin-bottom: 40px;
}

.product-detail-card:last-child {
  margin-bottom: 0;
}

.product-detail-card.reverse .img {
  order: 2;
}

.product-detail-card.reverse .detail {
  order: 1;
}

.product-detail-card .img {
  height: 384px;
  background: var(--bg-gray);
  display: flex;
  align-items: center;
  justify-content: center;
}

.product-detail-card .img svg {
  width: 200px;
  height: 160px;
  opacity: 0.2;
}

.product-detail-card .detail {
  padding: 48px;
}

.product-detail-card .detail h3 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 16px;
}

.product-detail-card .detail p {
  font-size: 15px;
  color: var(--text-body);
  line-height: 1.8;
  margin-bottom: 16px;
}

.product-detail-card .detail .spec-table {
  margin-top: 20px;
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

.product-detail-card .detail .spec-table th,
.product-detail-card .detail .spec-table td {
  padding: 10px 16px;
  border: 1px solid var(--border-light);
  text-align: left;
}

.product-detail-card .detail .spec-table th {
  background: var(--bg-light);
  color: var(--text-dark);
  font-weight: 600;
  width: 35%;
}

.product-detail-card .detail .spec-table td {
  color: var(--text-body);
}

/* 沟盖板数据表格优化 */
.cover-data-table {
  width: 100%;
  border-collapse: collapse;
  table-layout: fixed;
  font-size: 11px !important;
}

.cover-data-table thead th,
.cover-data-table tbody td {
  padding: 6px 3px;
  text-align: center;
  border: 1px solid var(--border-light);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.cover-data-table thead th {
  background: var(--bg-light);
  color: var(--text-dark);
  font-weight: 600;
  font-size: 11px;
  width: auto !important;
}

.cover-data-table tbody tr:nth-child(even) {
  background: #f8f9fb;
}

@media (max-width: 768px) {
  .about-advantages {
    grid-template-columns: 1fr;
  }

  .certs-grid {
    grid-template-columns: 1fr 1fr;
  }

  .product-detail-card {
    grid-template-columns: 1fr;
  }

  .product-detail-card.reverse .img,
  .product-detail-card.reverse .detail {
    order: unset;
  }

  .product-detail-card .detail {
    padding: 24px;
  }

  .cover-data-table {
    font-size: 10px !important;
  }

  .cover-data-table thead th,
  .cover-data-table tbody td {
    padding: 5px 2px;
  }
}

/* --- Tread Section --- */
.tread-intro {
  margin-bottom: 40px;
}

.tread-intro h3 {
  font-size: 28px;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 16px;
}

.tread-desc {
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

.tread-desc-en {
  font-size: 14px;
  line-height: 1.7;
  color: #888;
  font-style: italic;
  margin-bottom: 24px;
}

.tread-diagram {
  width: 100%;
  max-width: 800px;
  height: auto;
  display: block;
  margin: 0 auto 32px;
  border-radius: 8px;
  border: 1px solid var(--border-light);
}

.section-subtitle {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-dark);
  margin: 32px 0 20px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--primary);
  display: inline-block;
}

.tread-type-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 40px;
}

.tread-type-card {
  background: var(--bg-white);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 24px 20px;
  text-align: center;
  transition: var(--transition);
}

.tread-type-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-light);
}

.tread-type-card .type-code {
  font-size: 32px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 8px;
}

.tread-type-card .tread-type-img {
  width: 100%;
  height: auto;
  max-height: 140px;
  object-fit: contain;
  border-radius: 8px;
  margin-bottom: 12px;
}

.tread-type-card .type-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-dark);
  margin-bottom: 4px;
}

.tread-type-card .type-name-en {
  font-size: 12px;
  color: #999;
  line-height: 1.5;
}

.tread-spec-section {
  margin-bottom: 24px;
}

.tread-table th,
.tread-table td {
  background: #fff;
  color: #222;
  text-align: center;
  vertical-align: middle;
  border: 1px solid #333;
  font-weight: 500;
}

.tread-table thead th:first-child,
.tread-table tbody th:first-child {
  background: #f5f5f5;
  min-width: 140px;
}

.tread-table thead th:nth-child(2),
.tread-table tbody th:nth-child(2) {
  min-width: 80px;
}

.tread-table .en {
  font-size: 11px;
  opacity: 0.85;
  font-weight: 400;
}

.tread-spec-img {
  width: 60%;
  max-width: 480px;
  height: auto;
  display: block;
  margin: 0;
  border-radius: 4px;
  mix-blend-mode: multiply;
}

.tread-note {
  font-size: 13px;
  color: #888;
  margin-top: 12px;
  font-style: italic;
}

@media (max-width: 768px) {
  .tread-type-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .tread-type-card {
    padding: 16px 12px;
  }

  .tread-type-card .type-code {
    font-size: 24px;
  }

  .tread-table td,
  .tread-table th {
    font-size: 12px;
    padding: 8px 4px;
    min-width: auto;
  }
}

/* --- Cover Carousel --- */
.cover-carousel {
  position: relative;
  width: 100%;
  max-width: 900px;
  margin: 0 auto 28px;
  border-radius: 12px;
  overflow: hidden;
  background: #f0f0f0;
  aspect-ratio: 16 / 9;
}

.cover-carousel .carousel-track {
  display: flex;
  transition: transform 0.6s ease-in-out;
  height: 100%;
}

.cover-carousel .carousel-slide {
  min-width: 100%;
  height: 100%;
  flex-shrink: 0;
}

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

.cover-carousel .carousel-dots {
  position: absolute;
  bottom: 14px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 8px;
  z-index: 2;
}

.cover-carousel .carousel-dots button {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: none;
  background: rgba(255,255,255,0.5);
  cursor: pointer;
  transition: background 0.3s;
  padding: 0;
}

.cover-carousel .carousel-dots button.active {
  background: #fff;
}