body{font-family:Arial,sans-serif;background-color:#f0f0f0}body,h1,h2,h3,h4,h5,h6{margin:0;padding:0}a{text-decoration:none;color:inherit}.container{max-width:1200px;margin:0 auto;padding:20px}.notification{position:relative;padding:20px;border-radius:5px;background-color:#fff;box-shadow:0 2px 10px rgba(0,0,0,.1)}.sound-control{display:flex;align-items:center;margin-top:20px}.button{padding:10px 15px;border:none;border-radius:5px;background-color:#0070f3;color:#fff;cursor:pointer;transition:background-color .3s}.button:hover{background-color:#005bb5}