       @media (max-width: 768px) {
            .playground-container {
                grid-template-columns: 1fr;
            }
            
            .controls-panel {
                position: static;
                max-height: none;
            }
        }
    </style>
</head>
<body>
    <h1>Interactive CSS Flexbox Playground</h1>
    
    <div class="playground-container">
        <div class="controls-panel">
            <div class="tabs">
                <button class="tab active" onclick="showTab(