/* --- Reset & Base Styles --- */
        *, *::before, *::after {
            box-sizing: border-box;
        }
        
        body {
            margin: 0;
            padding: 0;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            color: #2c3e50;
            line-height: 1.7;
            background-color: #f8f9fa;
        }

        /* --- Container & Layout --- */
        .container {
            max-width: 800px;
            margin: 40px auto;
            background-color: #ffffff;
            padding: 40px 50px;
            border-radius: 8px;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
        }

        /* --- Header --- */
        header {
            border-bottom: 2px solid #3498db;
            padding-bottom: 20px;
            margin-bottom: 35px;
        }

        header h1 {
            color: #2c3e50;
            font-size: 28px;
            margin: 0 0 10px 0;
            font-weight: 700;
            letter-spacing: -0.5px;
        }

        header .updated {
            color: #7f8c8d;
            font-size: 14px;
            margin: 0;
            font-style: italic;
        }

        /* --- Content Sections --- */
        section {
            margin-bottom: 30px;
        }

        h2 {
            color: #2980b9;
            font-size: 18px;
            margin-top: 0;
            margin-bottom: 15px;
            padding-left: 12px;
            border-left: 4px solid #3498db;
            font-weight: 600;
        }

        p {
            margin: 0 0 15px 0;
            text-align: justify;
        }

        /* --- Lists Styling --- */
        ol {
            margin: 0 0 20px 0;
            padding-left: 20px;
        }

        ol > li {
            margin-bottom: 12px;
            font-weight: 500;
            color: #2c3e50;
        }

        ol > li::marker {
            color: #2980b9;
            font-weight: bold;
        }

        ul {
            margin: 8px 0 12px 0;
            padding-left: 20px;
            list-style-type: square;
        }

        ul li {
            margin-bottom: 6px;
            font-weight: normal;
            color: #4f5f6f;
        }

        /* --- Components --- */
        .alert-box {
            background-color: #fff5f5;
            border-left: 4px solid #e74c3c;
            padding: 15px 20px;
            margin: 20px 0;
            border-radius: 0 6px 6px 0;
        }

        .alert-box p {
            margin: 0;
            color: #c0392b;
        }

        .contact-info {
            background-color: #f8f9fa;
            border: 1px solid #e9ecef;
            border-radius: 6px;
            padding: 20px;
            margin-top: 20px;
        }

        .contact-info p {
            margin-bottom: 8px;
        }
        
        .contact-info p:last-child {
            margin-bottom: 0;
        }

        .contact-info strong {
            color: #34495e;
        }

        /* --- Responsive Media Queries --- */
        @media (max-width: 768px) {
            body {
                background-color: #ffffff;
            }
            .container {
                margin: 0;
                padding: 20px 20px;
                box-shadow: none;
            }
            header h1 {
                font-size: 24px;
            }
            h2 {
                font-size: 16px;
            }
        }

        /* --- Print Styles --- */
        @media print {
            body {
                background-color: #fff;
                font-size: 12pt;
            }
            .container {
                margin: 0;
                padding: 0;
                box-shadow: none;
                max-width: 100%;
            }
            .alert-box {
                background-color: #fff5f5 !important;
                border-left: 4px solid #000 !important;
            }
            .contact-info {
                background-color: #f8f9fa !important;
                border: 1px solid #ccc !important;
            }
        }
        /* --- THANH ĐIỀU HƯỚNG --- */
.navigation-header {
    display: flex;
    align-items: center;
    gap: 8px;
    background: #ffffff;
    padding: 12px 20px;
    border-radius: 8px;
    border: 1px solid #e2e8f0;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.02);
    margin-bottom: 5px;
}

.nav-home-link {
    font-size: 14.5px;
    font-weight: 600;
    color: #0056b3;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    transition: color 0.2s ease, transform 0.2s ease;
}

.nav-home-link:hover {
    color: #0042cc;
    transform: translateY(-1px);
}

.nav-separator {
    color: #94a3b8;
    font-size: 14px;
    user-select: none;
}

.nav-current {
    font-size: 14.5px;
    color: #64748b;
    font-weight: 500;
}

@media (max-width: 576px) {
    .navigation-header {
        padding: 10px 15px;
        font-size: 13.5px;
    }
}