/* --- MODERN INDUSTRIAL THEME --- */
    :root {
        --brand-primary: #1A365D; /* Deep Slate Blue */
        --brand-accent: #FF6B00;  /* Vibrant Safety Orange */
        --text-main: #2D3748;
        --text-muted: #718096;
        --bg-page: #F7FAFC;
        --bg-card: #FFFFFF;
        --border-color: #E2E8F0;
        --radius-md: 10px;
        --radius-lg: 16px;
        --shadow-sm: 0 2px 4px rgba(0,0,0,0.02);
        --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
        --shadow-hover: 0 8px 24px rgba(0,0,0,0.12);
    }

    /* 全局字体与字号设定 */
    body {
        font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
        font-size: 16px;
        color: var(--text-main);
        line-height: 1.6;
        margin: 0;
        padding: 20px;
        background-color: var(--bg-page);
    }

    .product-container {
        max-width: 1200px;
        margin: 0 auto;
    }

    /* --- 1. HERO SECTION --- */
    .hero-section {
        background: var(--bg-card);
        padding: 40px;
        border-radius: var(--radius-lg);
        box-shadow: var(--shadow-sm);
        margin-bottom: 30px;
        border-top: 5px solid var(--brand-primary);
        text-align: center;
    }

    .hero-title {
        font-size: 36px;
        color: var(--brand-primary);
        margin: 0 0 10px 0;
        font-weight: 800;
        letter-spacing: -0.5px;
    }
    
    .hero-subtitle {
        font-size: 18px;
        color: var(--text-muted);
        font-weight: 600;
        margin-bottom: 25px;
    }

    .hero-desc {
        font-size: 16px;
        color: var(--text-main);
        max-width: 900px;
        margin: 0 auto;
        text-align: left;
    }

    /* --- 2. MATRIX NAVIGATION (Product Categories) --- */
    .matrix-title {
        text-align: center;
        font-size: 24px;
        color: var(--brand-primary);
        margin-top: 40px;
        margin-bottom: 20px;
        font-weight: 700;
    }

    .matrix-grid {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
        gap: 20px;
        margin-bottom: 50px;
    }

    .matrix-card {
        background: var(--bg-card);
        border: 1px solid var(--border-color);
        border-radius: var(--radius-md);
        padding: 30px 20px;
        text-align: center;
        box-shadow: var(--shadow-sm);
        transition: transform 0.2s, box-shadow 0.2s;
    }

    .matrix-card:hover {
        transform: translateY(-5px);
        box-shadow: var(--shadow-hover);
        border-color: var(--brand-primary);
    }

    .matrix-icon {
        font-size: 40px;
        margin-bottom: 15px;
        display: block;
    }

    .matrix-header {
        font-size: 20px;
        color: var(--brand-primary);
        margin: 0 0 10px 0;
        font-weight: 700;
    }

    .matrix-desc {
        font-size: 14px;
        color: var(--text-muted);
        margin-bottom: 25px;
    }

    .btn-link {
        display: block;
        background: var(--bg-page);
        color: var(--brand-primary);
        text-decoration: none;
        padding: 10px 15px;
        border-radius: 6px;
        border: 1px solid var(--border-color);
        font-weight: 600;
        font-size: 14px;
        margin-bottom: 10px;
        transition: all 0.2s ease;
    }

    .btn-link:last-child { margin-bottom: 0; }
    
    .btn-link:hover {
        background: var(--brand-primary);
        color: #ffffff;
        border-color: var(--brand-primary);
    }

    /* --- 3. TWO-COLUMN LAYOUT (Types & Advantages) --- */
    .split-layout {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 30px;
        margin-bottom: 40px;
    }

    @media (max-width: 800px) {
        .split-layout { grid-template-columns: 1fr; }
    }

    .section-heading {
        font-size: 22px;
        color: var(--brand-primary);
        margin-bottom: 20px;
        display: flex;
        align-items: center;
        gap: 10px;
    }

    .section-heading::before {
        content: "";
        width: 6px;
        height: 24px;
        background: var(--brand-accent);
        border-radius: 4px;
    }

    /* Types List */
    .types-container {
        display: flex;
        flex-direction: column;
        gap: 15px;
    }

    .type-card {
        background: var(--bg-card);
        border-left: 4px solid var(--brand-primary);
        padding: 20px;
        border-radius: var(--radius-md);
        box-shadow: var(--shadow-sm);
        border-top: 1px solid var(--border-color);
        border-right: 1px solid var(--border-color);
        border-bottom: 1px solid var(--border-color);
    }

    .type-card strong {
        color: var(--brand-primary);
        font-size: 16px;
        display: block;
        margin-bottom: 5px;
    }

    .type-card p { margin: 0; font-size: 14px; color: var(--text-main); }

    /* Advantages Grid */
    .advantages-grid {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 15px;
    }

    @media (max-width: 500px) {
        .advantages-grid { grid-template-columns: 1fr; }
    }

    .adv-card {
        background: var(--bg-card);
        padding: 20px;
        border-radius: var(--radius-md);
        box-shadow: var(--shadow-sm);
        border: 1px solid var(--border-color);
    }

    .adv-title {
        color: var(--brand-primary);
        font-weight: 700;
        font-size: 15px;
        margin-bottom: 8px;
        display: flex;
        align-items: center;
        gap: 8px;
    }

    .adv-desc { margin: 0; font-size: 13px; color: var(--text-muted); }

    /* --- 4. SAFETY & VISUALS --- */
    .safety-banner {
        background-color: #EBF8FF;
        border-left: 5px solid #3182CE;
        padding: 25px;
        border-radius: var(--radius-md);
        margin-bottom: 40px;
    }

    .safety-banner h3 {
        color: #2B6CB0;
        margin: 0 0 10px 0;
        font-size: 18px;
    }

    .safety-banner p { margin: 0; color: var(--text-main); font-size: 15px;}

    .visual-footer {
        text-align: center;
        background: var(--bg-card);
        padding: 20px;
        border-radius: var(--radius-lg);
        box-shadow: var(--shadow-md);
    }

    .visual-footer img {
        max-width: 100%;
        height: auto;
        border-radius: 8px;
    }