<style>
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            color: #333;
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            line-height: 1.6;
            min-height: 100vh;
        }
        .container {
            max-width: 1000px;
            margin: 0 auto;
            padding: 40px 20px;
            background-color: white;
            box-shadow: 0 10px 40px rgba(0,0,0,0.1);
            border-radius: 8px;
        }
        header {
            text-align: center;
            margin-bottom: 40px;
            border-bottom: 4px solid #2c5aa0;
            padding-bottom: 30px;
        }
        h1 {
            color: #2c5aa0;
            font-size: 2.8em;
            margin-bottom: 10px;
        }
        .description {
            color: #666;
            font-size: 1.1em;
        }
        section {
            margin-bottom: 35px;
        }
        h2 {
            color: #2c5aa0;
            font-size: 1.6em;
            margin-bottom: 20px;
            padding-bottom: 12px;
            border-left: 5px solid #2c5aa0;
            padding-left: 15px;
        }
        .section-content {
            margin-left: 20px;
        }
        ul {
            list-style-position: inside;
        }
        li {
            margin-bottom: 12px;
            padding-left: 10px;
        }
        li ul {
            margin-top: 8px;
            margin-left: 30px;
            list-style-type: circle;
        }
        li ul li {
            margin-bottom: 8px;
        }
        a {
            color: #2c5aa0;
            text-decoration: none;
            font-weight: 500;
            transition: all 0.3s ease;
        }
        a:hover {
            color: #1a3a5c;
            text-decoration: underline;
        }
        .category {
            background-color: #f9f9f9;
            padding: 15px;
            border-radius: 5px;
            margin-bottom: 15px;
        }
        footer {
            margin-top: 40px;
            padding-top: 20px;
            border-top: 2px solid #ddd;
            text-align: center;
            color: #666;
            font-size: 0.9em;
        }
        .back-to-top {
            text-align: center;
            margin-top: 20px;
        }
        .back-to-top a {
            background-color: #2c5aa0;
            color: white;
            padding: 10px 20px;
            border-radius: 5px;
            display: inline-block;
        }
        .back-to-top a:hover {
            background-color: #1a3a5c;
            text-decoration: none;
        }
    </style>