apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', sans-serif;
            background-color: var(--bg-color);
            color: var(--text-color);
            margin: 0;
            padding: 0;
            line-height: 1.6;
            transition: background-color 0.3s, color 0.3s;
        }

        .theme-toggle {
            position: fixed;
            top: 20px;
            right: 20px;
            background: var(--primary-color);
            color: white;
            border: none;
            b