body {
    font-family: sans-serif;
    max-width: 400px;
    margin: 2rem auto;
    padding: 1rem;
}

input {
    width: 100%;
    padding: 8px;
    margin-top: 5px;
    margin-bottom: 10px;
}

button {
    width: 100%;
    padding: 10px;
    background: #28a745;
    color: white;
    border: none;
    cursor: pointer;
}

.error {
    color: red;
    display: none;
}