* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: Arial, sans-serif;
        }

        body {
            display: flex;
            flex-direction: column;
            min-height: 100vh;
            background-color: #f4f4f4;
        }

        header {
            background: #333;
            color: #fff;
            padding: 20px;
            text-align: center;
            font-size: 24px;
        }

        nav {
            background: #444;
            padding: 10px;
        }

        nav ul {
            list-style: none;
            display: flex;
            justify-content: center;
        }

        nav ul li {
            margin: 0 15px;
        }

        nav ul li a {
            text-decoration: none;
            color: #fff;
            font-size: 18px;
        }

        .container {
            display: flex;
            flex: 1;
            max-width: 1200px;
            margin: 20px auto;
            gap: 20px;
        }

        .main-content {
            flex: 2;
            background: #fff;
            padding: 20px;
            border-radius: 8px;
            box-shadow: 0px 0px 10px rgba(0, 0, 0, 0.1);
        }

        .sidebar {
            flex: 1;
            background: #ddd;
            padding: 20px;
            border-radius: 8px;
        }

        footer {
            background: #333;
            color: #fff;
            text-align: center;
            padding: 15px;
            margin-top: 20px;
        }

        @media (max-width: 768px) {
            .container {
                flex-direction: column;
                padding: 10px;
            }
        }