/* Base Reset and Typography */
        :root {
            --primary-blue: #0056b3; /* Darker blue for headers */
            --secondary-blue: #e3f2fd; /* Light blue for backgrounds */
            --accent-orange: #ff9800; /* Orange for highlights/buttons */
            --text-dark: #333333;
            --text-light: #555555;
            --white: #ffffff;
            --border-color: #dee2e6;
        }

        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        body {
            font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
            font-size: 16px;
            line-height: 1.6;
            color: var(--text-dark);
            background-color: #f9f9f9;
        }

        /* Layout Utility */
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }

        /* Header */
        header {
            background-color: var(--primary-blue);
            color: var(--white);
            padding: 40px 0;
            text-align: center;
            box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        }

        header h1 {
            font-size: 2.5rem;
            margin-bottom: 10px;
            font-weight: 700;
        }

        /* 修改了这里的颜色，使用橙色 */
        header p {
            font-size: 1.2rem;
            color: var(--accent-orange); /* Changed to Orange */
            font-weight: 600; /* Added weight for better visibility */
            letter-spacing: 0.5px;
            opacity: 1; /* Removed opacity */
        }

        /* Navigation */
        nav {
            background-color: #004494;
            padding: 10px 0;
            position: sticky;
            top: 0;
            z-index: 100;
        }

        nav ul {
            list-style: none;
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
            gap: 20px;
        }

        nav a {
            color: var(--white);
            text-decoration: none;
            font-weight: 500;
            font-size: 0.95rem;
            padding: 5px 10px;
            transition: color 0.3s;
        }

        nav a:hover {
            color: var(--accent-orange);
        }

        /* Main Content Styling */
        main {
            padding: 40px 0;
        }

        section {
            background: var(--white);
            border-radius: 8px;
            padding: 30px;
            margin-bottom: 30px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.05);
            border-top: 4px solid var(--accent-orange);
        }

        h2 {
            color: var(--primary-blue);
            font-size: 1.8rem;
            margin-bottom: 20px;
            border-bottom: 2px solid var(--secondary-blue);
            padding-bottom: 10px;
        }

        h3 {
            color: #003d80;
            font-size: 1.4rem;
            margin-top: 25px;
            margin-bottom: 15px;
        }

        h4 {
            color: var(--text-dark);
            font-size: 1.1rem;
            margin-top: 15px;
            margin-bottom: 10px;
            font-weight: 700;
        }

        p {
            margin-bottom: 15px;
            color: var(--text-light);
            text-align: justify;
        }

        ul, ol {
            margin-left: 20px;
            margin-bottom: 20px;
            color: var(--text-light);
        }

        li {
            margin-bottom: 8px;
        }

        /* Highlight Boxes */
        .highlight-box {
            background-color: var(--secondary-blue);
            border-left: 5px solid var(--primary-blue);
            padding: 20px;
            margin: 20px 0;
            border-radius: 4px;
        }

        .warning-box {
            background-color: #fff3e0;
            border-left: 5px solid var(--accent-orange);
            padding: 20px;
            margin: 20px 0;
            border-radius: 4px;
        }

        .quote {
            font-size: 1.25rem;
            font-weight: bold;
            color: var(--accent-orange);
            text-align: center;
            font-style: italic;
            margin: 10px 0;
        }

        /* Tables */
        .table-responsive {
            overflow-x: auto;
            margin: 20px 0;
        }

        table {
            width: 100%;
            border-collapse: collapse;
            font-size: 0.95rem;
        }

        th, td {
            padding: 12px 15px;
            border: 1px solid var(--border-color);
            text-align: left;
        }

        th {
            background-color: var(--primary-blue);
            color: var(--white);
            font-weight: 600;
        }

        tr:nth-child(even) {
            background-color: #f8f9fa;
        }

        tr:hover {
            background-color: #e9ecef;
        }

        /* Step List Styling */
        .step-list {
            counter-reset: step;
            list-style: none;
            margin-left: 0;
        }

        .step-list li {
            position: relative;
            padding-left: 50px;
            margin-bottom: 20px;
        }

        .step-list li::before {
            counter-increment: step;
            content: counter(step);
            position: absolute;
            left: 0;
            top: 0;
            width: 35px;
            height: 35px;
            background-color: var(--accent-orange);
            color: var(--white);
            border-radius: 50%;
            text-align: center;
            line-height: 35px;
            font-weight: bold;
        }

        /* Grid for cards */
        .card-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 20px;
            margin-top: 20px;
        }

        .card {
            background: #fff;
            border: 1px solid var(--border-color);
            border-radius: 6px;
            padding: 20px;
            transition: transform 0.2s;
        }

        .card:hover {
            transform: translateY(-5px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            border-color: var(--accent-orange);
        }

        .card h4 {
            color: var(--primary-blue);
            margin-top: 0;
        }

        /* Footer */
        footer {
            background-color: #333;
            color: #ccc;
            text-align: center;
            padding: 30px 0;
            margin-top: 40px;
            font-size: 0.9rem;
        }

        footer p {
            color: #ccc;
            text-align: center;
            margin-bottom: 5px;
        }

        /* Responsive Tweaks */
        @media (max-width: 768px) {
            header h1 { font-size: 2rem; }
            section { padding: 20px; }
            .card-grid { grid-template-columns: 1fr; }
            nav ul { flex-direction: column; align-items: center; gap: 10px; }
        }