/* ══════════════════════════════════════════════�?   Product Detail Page - Hongbo Gas Equipment (v2)
   ══════════════════════════════════════════════�?*/

/* ── Breadcrumb ── */
.breadcrumb-section {
    background: #f8fafc;
    border-bottom: 1px solid #e2e8f0;
}

.breadcrumb {
    padding: 14px 0;
    font-size: 13px;
    color: #94a3b8;
}

.breadcrumb a {
    color: #2563eb;
    text-decoration: none;
}

.breadcrumb a:hover { text-decoration: underline; }

.breadcrumb-sep {
    margin: 0 8px;
    color: #cbd5e1;
}

.breadcrumb-current { color: #475569; font-weight: 500; }

/* ── Product Hero ── */
.product-hero-section {
    padding: 40px 0;
    background: #fff;
}

.product-hero-wrapper {
    display: flex;
    gap: 40px;
    align-items: flex-start;
}

.product-hero-image {
    flex: 0 0 420px;
    position: relative;
}

.hero-badge {
    position: absolute;
    top: 12px;
    left: 12px;
    z-index: 20;
    background: linear-gradient(135deg, #f97316, #ef4444);
    color: #fff;
    padding: 6px 14px;
    border-radius: 6px;
    font-size: 13px;
    font-weight: 700;
    box-shadow: 0 2px 8px rgba(239,68,68,0.3);
}

/* ════════════════════════════════════════
   Image Carousel
   ════════════════════════════════════════ */
.carousel-container {
    width: 100%;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0,0,0,0.06);
    border: 1px solid #e2e8f0;
    background: #f8fafc;
}

.carousel-main {
    position: relative;
    width: 100%;
    aspect-ratio: 4/3;
    overflow: hidden;
    background: #f1f5f9;
}

.carousel-track {
    position: relative;
    width: 100%;
    height: 100%;
}

.carousel-slide {
    position: absolute;
    top: 0; left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 0.5s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.carousel-slide.active {
    opacity: 1;
    z-index: 1;
}

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

.img-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #f1f5f9;
    color: #94a3b8;
    font-size: 32px;
    font-weight: 700;
}

/* Carousel Buttons */
.carousel-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    z-index: 10;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(255,255,255,0.85);
    border: none;
    cursor: pointer;
    font-size: 22px;
    font-weight: 700;
    color: #1e293b;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
    box-shadow: 0 2px 8px rgba(0,0,0,0.12);
    opacity: 0;
}

.carousel-container:hover .carousel-btn {
    opacity: 1;
}

.carousel-btn:hover {
    background: #fff;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
    transform: translateY(-50%) scale(1.1);
}

.carousel-prev { left: 12px; }
.carousel-next { right: 12px; }

/* Dots */
.carousel-indicators {
    position: absolute;
    bottom: 12px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 6px;
    z-index: 10;
}

.carousel-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: rgba(255,255,255,0.5);
    cursor: pointer;
    transition: all 0.3s;
}

.carousel-dot.active {
    background: #fff;
    width: 24px;
    border-radius: 4px;
    box-shadow: 0 0 6px rgba(0,0,0,0.3);
}

/* Counter */
.carousel-counter {
    position: absolute;
    bottom: 12px;
    right: 12px;
    z-index: 10;
    background: rgba(0,0,0,0.5);
    color: #fff;
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
    backdrop-filter: blur(4px);
}

/* Thumbnails */
.carousel-thumbs {
    display: flex;
    gap: 6px;
    padding: 10px 12px;
    overflow-x: auto;
    background: #fff;
    border-top: 1px solid #e2e8f0;
    scrollbar-width: thin;
}

.carousel-thumb {
    flex: 0 0 64px;
    height: 48px;
    border-radius: 6px;
    overflow: hidden;
    cursor: pointer;
    border: 2px solid transparent;
    transition: all 0.2s;
    opacity: 0.6;
}

.carousel-thumb:hover {
    opacity: 0.9;
    border-color: #94a3b8;
}

.carousel-thumb.active {
    opacity: 1;
    border-color: #2563eb;
    box-shadow: 0 0 0 2px rgba(37,99,235,0.2);
}

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

/* Info Side */
.product-hero-info {
    flex: 1;
    min-width: 280px;
}

.hero-meta {
    display: flex;
    gap: 8px;
    margin-bottom: 12px;
}

.hero-category {
    display: inline-block;
    background: #eef4ff;
    color: #2563eb;
    font-size: 12px;
    font-weight: 700;
    padding: 4px 14px;
    border-radius: 20px;
    letter-spacing: 0.5px;
}

.hero-series {
    display: inline-block;
    background: #eef2ff;
    color: #6366f1;
    font-size: 12px;
    font-weight: 600;
    padding: 4px 14px;
    border-radius: 20px;
}

.hero-title {
    font-size: 32px;
    font-weight: 800;
    color: #0f172a;
    margin: 0 0 8px 0;
    line-height: 1.25;
    letter-spacing: -0.5px;
}

.hero-subtitle {
    font-size: 16px;
    color: #2563eb;
    font-weight: 500;
    margin-bottom: 12px;
    border-left: 3px solid #2563eb;
    padding-left: 14px;
}

.hero-desc {
    font-size: 15px;
    color: #475569;
    line-height: 1.7;
    margin-bottom: 24px;
    background: #f8fafc;
    padding: 16px 20px;
    border-radius: 10px;
    border: 1px solid #e2e8f0;
}

/* Key Specs */
.hero-specs {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 20px;
}

.spec-item {
    display: flex;
    align-items: center;
    gap: 6px;
    background: #f8fafc;
    padding: 10px 16px;
    border-radius: 10px;
    border: 1px solid #e2e8f0;
    transition: border-color 0.2s;
}

.spec-item:hover { border-color: #2563eb; }

.spec-icon { font-size: 16px; }

.spec-label {
    font-size: 11px;
    color: #94a3b8;
    font-weight: 500;
}

.spec-value {
    font-size: 14px;
    color: #0f172a;
    font-weight: 600;
}

/* Tags */
.hero-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 24px;
}

.hero-tag {
    font-size: 11px;
    color: #64748b;
    background: #f1f5f9;
    padding: 4px 12px;
    border-radius: 6px;
    border: 1px solid #e2e8f0;
}

/* Buttons */
.hero-actions {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.btn {
    padding: 13px 28px;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.25s;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    border: none;
    font-size: 15px;
}

.btn-primary {
    background: linear-gradient(135deg, #2563eb, #3b82f6);
    color: #fff;
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
    background: linear-gradient(135deg, #1d4ed8, #2563eb);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}

.btn-outline {
    background: transparent;
    border: 2px solid #e2e8f0;
    color: #475569;
}

.btn-outline:hover {
    border-color: #2563eb;
    color: #2563eb;
    background: #f0f7ff;
}

.btn-icon { font-size: 18px; }

.btn-sm {
    padding: 10px 20px;
    font-size: 13px;
}

/* ── Content Tabs ── */
.product-content-section {
    padding: 40px 0 20px;
    background: #f8fafc;
}

.content-tabs-wrapper {
    background: #fff;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 2px 12px rgba(0,0,0,0.04);
    border: 1px solid #e2e8f0;
}

.content-tabs-nav {
    display: flex;
    gap: 0;
    border-bottom: 1px solid #e2e8f0;
    background: #fafbfc;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.tab-btn {
    padding: 14px 22px;
    background: none;
    border: none;
    border-bottom: 3px solid transparent;
    cursor: pointer;
    font-weight: 600;
    font-size: 14px;
    color: #94a3b8;
    white-space: nowrap;
    transition: all 0.2s;
}

.tab-btn:hover {
    color: #2563eb;
    background: #f0f7ff;
}

.tab-btn.active {
    color: #2563eb;
    border-bottom-color: #2563eb;
    background: #f0f7ff;
}

.content-tabs-body {
    padding: 30px 40px;
    min-height: 300px;
}

.tab-panel {
    display: none;
}

.tab-panel.active {
    display: block;
}

/* ── Section Heading ── */
.section-heading {
    font-size: 24px;
    font-weight: 700;
    color: #0f172a;
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.heading-icon { font-size: 22px; }

/* ── Rich Text ── */
.rich-text {
    line-height: 1.85;
    color: #334155;
    font-size: 15px;
}

.rich-text h2 {
    font-size: 22px;
    color: #0f172a;
    margin: 28px 0 14px;
    font-weight: 700;
}

.rich-text h3 {
    font-size: 18px;
    color: #0f172a;
    margin: 24px 0 10px;
    font-weight: 600;
}

.rich-text h4 {
    font-size: 16px;
    color: #1e293b;
    margin: 18px 0 8px;
    font-weight: 600;
}

.rich-text p { margin: 8px 0; }

.rich-text ul, .rich-text ol {
    margin: 10px 0;
    padding-left: 24px;
}

.rich-text li { margin: 4px 0; }

.rich-text table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    font-size: 14px;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 1px 4px rgba(0,0,0,0.04);
}

.rich-text thead th {
    background: #1e40af;
    color: #fff;
    padding: 12px 16px;
    text-align: left;
    font-weight: 600;
    font-size: 13px;
}

.rich-text tbody td {
    padding: 11px 16px;
    border-bottom: 1px solid #f1f5f9;
}

.rich-text tbody tr:nth-child(even) td {
    background: #f8fafc;
}

.rich-text tbody tr:hover td {
    background: #eef4ff;
}

.rich-text pre {
    background: #0f172a;
    color: #e2e8f0;
    padding: 16px 20px;
    border-radius: 10px;
    overflow-x: auto;
    border: 1px solid #1e293b;
    font-size: 13px;
}

.rich-text code {
    font-family: 'Consolas', 'Monaco', 'Fira Code', monospace;
    font-size: 13px;
}

.rich-text hr {
    border: none;
    border-top: 1px solid #e2e8f0;
    margin: 28px 0;
}

.rich-text strong {
    color: #0f172a;
}

.rich-text blockquote {
    border-left: 4px solid #2563eb;
    padding: 12px 20px;
    margin: 16px 0;
    background: #f0f7ff;
    border-radius: 0 8px 8px 0;
    color: #475569;
}

/* ── Image Gallery ── */
.product-gallery-section {
    padding: 40px 0;
    background: #fff;
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 12px;
}

.gallery-item {
    border-radius: 10px;
    overflow: hidden;
    border: 1px solid #e2e8f0;
    background: #f8fafc;
    aspect-ratio: 4/3;
}

.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s;
}

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

/* ── Related Products ── */
.related-products-section {
    padding: 40px 0 50px;
    background: #f8fafc;
}

.related-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 20px;
}

.related-card {
    display: flex;
    flex-direction: column;
    background: #fff;
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid #e2e8f0;
    text-decoration: none;
    color: inherit;
    transition: all 0.25s;
}

.related-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.08);
    border-color: #2563eb;
}

.related-card-img {
    height: 160px;
    overflow: hidden;
    background: #f1f5f9;
}

.related-card-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s;
}

.related-card:hover .related-card-img img {
    transform: scale(1.06);
}

.related-card-body {
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.related-category {
    font-size: 10px;
    color: #2563eb;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.related-card-body h4 {
    margin: 0;
    font-size: 16px;
    color: #0f172a;
    font-weight: 600;
    line-height: 1.3;
}

.related-card-body p {
    margin: 0;
    font-size: 12px;
    color: #64748b;
    line-height: 1.4;
}

.related-model {
    font-size: 11px;
    color: #6366f1;
    font-weight: 600;
    background: #eef2ff;
    padding: 2px 8px;
    border-radius: 4px;
    display: inline-block;
    align-self: flex-start;
}

/* ── Sticky Action Bar ── */
.sticky-action-bar {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(12px);
    border-top: 1px solid #e2e8f0;
    padding: 12px 0;
    z-index: 1000;
    transform: translateY(100%);
    transition: transform 0.3s ease;
    box-shadow: 0 -4px 16px rgba(0,0,0,0.06);
}

.sticky-action-bar.visible {
    transform: translateY(0);
}

.sticky-action-bar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.sticky-product-name {
    font-size: 15px;
    font-weight: 600;
    color: #0f172a;
}

.sticky-buttons {
    display: flex;
    gap: 10px;
}

/* ── Container ── */


/* ── Back to Top Button ── */
.back-to-top {
    position: fixed;
    bottom: 80px;
    right: 30px;
    z-index: 999;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: linear-gradient(135deg, #2563eb, #3b82f6);
    color: #fff;
    border: none;
    font-size: 22px;
    font-weight: 700;
    cursor: pointer;
    box-shadow: 0 4px 16px rgba(37, 99, 235, 0.3);
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    line-height: 1;
}

.back-to-top.visible {
    opacity: 1;
    transform: translateY(0);
}

.back-to-top:hover {
    background: linear-gradient(135deg, #1d4ed8, #2563eb);
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}

/* ── Mobile ── */
@media (max-width: 768px) {
    .product-hero-wrapper { flex-direction: column; }
    .product-hero-image { flex: none; width: 100%; max-width: 100%; }
    .hero-title { font-size: 24px; }
    .carousel-main { aspect-ratio: 4/3; }
    .carousel-btn { width: 32px; height: 32px; font-size: 18px; opacity: 0.8; }
    .carousel-thumbs { padding: 8px; gap: 4px; }
    .carousel-thumb { flex: 0 0 52px; height: 40px; }
    .back-to-top { width: 40px; height: 40px; font-size: 18px; bottom: 20px; right: 16px; }
    .content-tabs-body { padding: 20px; }
    .content-tabs-nav { overflow-x: auto; }
    .tab-btn { font-size: 13px; padding: 12px 16px; }
    .related-grid { grid-template-columns: 1fr 1fr; }
    .sticky-action-bar .container { flex-direction: column; gap: 8px; }
    .sticky-product-name { font-size: 13px; }
}