*{box-sizing:border-box}body{font-family:Arial,sans-serif;line-height:1.6;color:#333;background-color:#f4f7f9;margin:0;padding:0}.container{max-width:1200px;margin:0 auto;padding:20px}header{background-color:#2c3e50;color:#ecf0f1;text-align:center;padding:1rem}h1,h2{margin:0}.back-to-sandbox,a{text-align:left;color:#ecf0f1;text-decoration:none;background-color:#2c3e50;padding:5px}.sections{display:flex;justify-content:center;flex-wrap:wrap;margin-top:2rem}.section{width:500px;margin:20px;background-color:#fff;border-radius:8px;padding:20px;box-shadow:0 4px 6px #0000001a}textarea,input[type=file]{width:100%;margin-bottom:1rem;padding:10px;border:1px solid #bdc3c7;border-radius:4px}textarea{height:100px;resize:vertical}button{background-color:#3498db;color:#fff;border:none;padding:10px 20px;border-radius:4px;cursor:pointer;transition:background-color .3s ease}button:hover{background-color:#2980b9}.preview{margin-top:1rem;border:1px solid #bdc3c7;border-radius:4px;height:300px;display:flex;align-items:center;justify-content:center;background-color:#ecf0f1;overflow:hidden}#videoPreview video,#imagePreview img{max-width:100%;max-height:100%;object-fit:contain}.input-group{margin-bottom:1rem}label{display:block;margin-bottom:.5rem;font-weight:700}