body {
    font-family: sans-serif;
    background-color: #f0f0f0;
    color: #000;
    margin: 30px;
}

h1 {
    color: #000;
}

.container {
    background: #fff;
    padding: 20px;
    border: 1px solid #ccc;
}

textarea {
    width: 100%;
    height: 100px;
    margin-bottom: 10px;
}

button {
    padding: 10px;
    cursor: pointer;
}

button:hover {
    background-color: #000;
    color: #fff;
}

#res {
    margin-top: 20px;
    background: #eee;
    color: #000;
    padding: 10px;
    border: 1px solid #000;
    white-space: pre-wrap;
}

.error-text {
    color: red;
    margin-top: 5px;
}