:root {
        --font-main: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
        --bg-color: #f0f2f5; --bg-secondary-color: #ffffff; --text-color: #1c1e21;
        --text-secondary-color: #606770; --border-color: rgba(0, 0, 0, 0.1);
        --accent-color: #0062ff; --accent-color-hover: #0058e6;
        --shadow-color: rgba(0, 0, 0, 0.05); --glass-bg: rgba(255, 255, 255, 0.7);
    }
    html.dark {
        --bg-color: #18191a; --bg-secondary-color: #242526; --text-color: #e4e6eb;
        --text-secondary-color: #b0b3b8; --border-color: rgba(255, 255, 255, 0.15);
        --accent-color: #2e89ff; --accent-color-hover: #409cff;
        --shadow-color: rgba(0, 0, 0, 0.3); --glass-bg: rgba(36, 37, 38, 0.75);
    }
    *, *::before, *::after { box-sizing: border-box; }
    body { font-family: var(--font-main); margin: 0; background-color: var(--bg-color); color: var(--text-color); line-height: 1.6; font-weight: 400; -webkit-font-smoothing: antialiased; }
    .container { padding: 1rem 1.5rem; max-width: 1280px; margin: 0 auto; }
    .site-header { position: sticky; top: 0; z-index: 1000; background-color: var(--glass-bg); -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px); border-bottom: 1px solid var(--border-color); }
    .site-header nav { display: flex; justify-content: space-between; align-items: center; }
    .site-header .logo { font-weight: 700; font-size: 1.25rem; text-decoration: none; color: var(--text-color); }
    .nav-links { display: flex; align-items: center; gap: 1rem; }
    .nav-links a { text-decoration: none; color: var(--text-secondary-color); font-weight: 500; transition: color 0.2s ease; }
    .nav-links a:hover { color: var(--text-color); }
    .nav-actions { display: flex; align-items: center; gap: 0.5rem; }
    .theme-toggle { background: none; border: none; cursor: pointer; padding: 0.5rem; display: flex; align-items: center; }
    .theme-toggle .icon { stroke: var(--text-secondary-color); }
    .theme-toggle .sun { display: none; } html.dark .theme-toggle .sun { display: block; }
    .theme-toggle .moon { display: block; } html.dark .theme-toggle .moon { display: none; }
    .burger-menu { background: none; border: none; cursor: pointer; padding: 0.5rem; display: none; }
    .burger-menu .icon { stroke: var(--text-secondary-color); }
    .grid, .product-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.5rem; }
    .card, .product-card { background: var(--bg-secondary-color); border: 1px solid var(--border-color); border-radius: 12px; text-decoration: none; color: var(--text-color); transition: transform 0.2s ease, box-shadow 0.2s ease; overflow: hidden; display: flex; flex-direction: column; box-shadow: 0 4px 12px var(--shadow-color); }
    .card:hover, .product-card:hover { transform: translateY(-6px); box-shadow: 0 10px 20px var(--shadow-color); }
    .card-image-container img { width: 100%; height: auto; aspect-ratio: 1/1; object-fit: cover; }
    .card-content { padding: 1rem; flex-grow: 1; display: flex; flex-direction: column; }
    .card h3, .product-card h3 { font-size: 1rem; margin: 0 0 0.5rem 0; font-weight: 500; flex-grow: 1; }
    .price { font-weight: 700; color: var(--accent-color); margin-top: auto; font-size: 1.1rem; }
    .card-link { color: var(--accent-color); font-weight: 500; margin-top: auto; }
    .filters { display: flex; flex-direction: column; gap: 1rem; margin-bottom: 2rem; }
    .filters input, .filters select { padding: 0.75rem 1rem; border: 1px solid var(--border-color); background-color: var(--bg-secondary-color); color: var(--text-color); border-radius: 8px; font-size: 1rem; }
    .product-detail-grid { display: grid; grid-template-columns: 1fr; gap: 2rem; padding-top: 1rem; }
    .main-product-image { width: 100%; border-radius: 12px; }
    .thumbnail-container { display: flex; gap: 0.5rem; margin-top: 1rem; flex-wrap: wrap; }
    .alt-image-thumb { width: 60px; height: 60px; cursor: pointer; border: 2px solid var(--border-color); border-radius: 8px; object-fit: cover; transition: border-color 0.2s ease; }
    .alt-image-thumb:hover, .alt-image-thumb.active { border-color: var(--accent-color); }
    .product-info h1 { font-size: 1.5rem; margin-top: 0; }
    .variant-selector { margin: 1rem 0; }
    .variant-selector label { display: block; margin-bottom: 0.5rem; font-weight: 500; }
    .variant-selector select { width: 100%; padding: 0.75rem; border: 1px solid var(--border-color); border-radius: 8px; background-color: var(--bg-secondary-color); color: var(--text-color); -webkit-appearance: none; appearance: none; background-image: url('data:image/svg+xml;charset=US-ASCII,%3Csvg%20xmlns%3D%22http%3A//www.w3.org/2000/svg%22%20width%3D%22292.4%22%20height%3D%22292.4%22%3E%3Cpath%20fill%3D%22%23606770%22%20d%3D%22M287%2069.4a17.6%2017.6%200%200%200-13-5.4H18.4c-5%200-9.3%201.8-12.9%205.4A17.6%2017.6%200%200%200%200%2082.2c0%205%201.8%209.3%205.4%2012.9l128%20127.9c3.6%203.6%207.8%205.4%2012.8%205.4s9.2-1.8%2012.8-5.4L287%2095c3.5-3.5%205.4-7.8%205.4-12.8%200-5-1.9-9.2-5.5-12.8z%22/%3E%3C/svg%3E'); background-repeat: no-repeat; background-position: right .7em top 50%; background-size: .65em auto; font-size: 1rem; }
    .buy-now-btn { display: inline-block; background: var(--accent-color); color: white !important; padding: 0.8rem 2rem; border-radius: 8px; text-decoration: none; margin-top: 1.5rem; text-align: center; font-weight: 500; border: none; transition: transform 0.2s ease, box-shadow 0.2s ease; }
    .buy-now-btn:hover { transform: scale(1.05); box-shadow: 0 4px 15px rgba(0, 123, 255, 0.4); }
    .social-share { margin-top: 1.5rem; display: flex; align-items: center; gap: 1rem; }
    .social-share a { color: var(--text-secondary-color); font-size: 1.2rem; transition: color 0.2s ease; }
    .social-share a:hover { color: var(--accent-color); }
    .faq-section { max-width: 900px; margin: 2rem auto 0; }
    .faq-item { background: var(--bg-secondary-color); border: 1px solid var(--border-color); border-radius: 8px; margin-bottom: 1rem; }
    .faq-item summary { font-weight: 500; cursor: pointer; padding: 1rem; }
    .faq-item p { padding: 0 1rem 1rem; margin: 0; color: var(--text-secondary-color); }
    .internal-links ul { list-style: none; padding: 0; columns: 2; }
    .internal-links a { text-decoration: none; color: var(--text-secondary-color); } .internal-links a:hover { color: var(--accent-color); }
    .section-title { font-size: 1.5rem; margin: 3rem 0 1.5rem; border-bottom: 3px solid var(--accent-color); padding-bottom: 0.5rem; display: inline-block; }
    .site-footer { padding: 3rem 0; margin-top: 3rem; background-color: var(--bg-secondary-color); border-top: 1px solid var(--border-color); }
    .footer-grid { display: grid; grid-template-columns: 1fr; gap: 2rem; margin-bottom: 2rem; }
    .footer-column h4 { margin-top: 0; }
    .footer-column ul { list-style: none; padding: 0; margin: 0; }
    .footer-column li { display: flex; align-items: center; gap: 0.5rem; margin-bottom: 0.5rem; }
    .footer-column a { text-decoration: none; color: var(--text-secondary-color); } .footer-column a:hover { color: var(--accent-color); }
    .footer-bottom { text-align: center; border-top: 1px solid var(--border-color); padding-top: 1.5rem; font-size: 0.9rem; color: var(--text-secondary-color); }
    .breadcrumbs { margin-bottom: 1rem; font-size: 0.9em; } .breadcrumbs a { color: var(--accent-color); text-decoration: none; }
    #pagination { display: flex; justify-content: center; align-items: center; padding: 2rem 0; }
    #pagination button { padding: 0.5rem 1rem; margin: 0 0.25rem; border: 1px solid var(--border-color); background: var(--bg-secondary-color); color: var(--text-color); cursor: pointer; border-radius: 4px; }
    #pagination button:disabled { background: var(--accent-color); color: #fff; cursor: not-allowed; }
    #pagination span.ellipsis { padding: 0 0.5rem; }
    @media (max-width: 767px) {
        .nav-links { display: none; position: absolute; top: 100%; left: 0; right: 0; background-color: var(--bg-secondary-color); flex-direction: column; align-items: stretch; padding: 1rem; border-bottom: 1px solid var(--border-color); }
        #mainNav.nav-active .nav-links { display: flex; }
        .burger-menu { display: block; }
    }
    @media (min-width: 640px) { .footer-grid { grid-template-columns: repeat(3, 1fr); } }
    @media (min-width: 768px) { .filters { flex-direction: row; } .product-info h1 { font-size: 1.8rem; } }
    @media (min-width: 1024px) { .product-detail-grid { grid-template-columns: 1.2fr 1fr; gap: 3rem; } .product-info h1 { font-size: 2.2rem; } }