interface/styles.css

body {
    background: #000;
    color: #fff;
    font-family: Arial;
    padding: 40px;
}

textarea {
    width: 100%;
    height: 120px;
    margin-top: 20px;
}

button {
    margin-top: 20px;
    padding: 12px 24px;
    background: red;
    color: white;
    border: none;
}

#output {
    margin-top: 30px;
}