body{font-family:Arial,sans-serif;background-color:#f4f4f9;margin:0;padding:0}.demo-container{text-align:center;padding:2rem}header{margin-bottom:2rem}header h1{font-size:2.5rem;color:#333}header p{font-size:1.2rem;color:#555}.links a{margin:0 1rem;font-size:1.1rem;color:#007acc;text-decoration:none}.links a:hover{text-decoration:underline}.open-modal-btn{padding:.8rem 1.5rem;font-size:1.2rem;background-color:#007acc;color:#fff;border:none;border-radius:5px;cursor:pointer;transition:background-color .3s ease}.open-modal-btn:hover{background-color:#005f99}footer{margin-top:3rem;font-size:.9rem;color:#555}