body {
    font-family: Arial, sans-serif;
    text-align: center;
    background-color: #f4f4f4;
    padding: 20px;
}

.container {
    background: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0px 0px 10px rgba(0, 0, 0, 0.1);
    width: 300px;
    margin: auto;
}

#ledDisplay {
    width: 100px;
    height: 100px;
    margin: 20px auto;
    border-radius: 50%;
    background-color: red;
    transition: background-color 0.3s, opacity 0.3s;
}