:root {
            --bg: #0f172a;
            --card: #1e293b;
            --text: #f8fafc;
            --accent: #38bdf8;
        }

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background-color: var(--bg);
            color: var(--text);
            margin: 0;
            display: flex;
            flex-direction: column;
            align-items: center;
            min-height: 100vh;
        }

        header { margin: 20px 0; text-align: center; }

        .main-container {
            display: flex;
            gap: 20px;
            padding: 20px;
            flex-wrap: wrap;
            justify-content: center;
        }