body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    margin: 0;
    padding: 30px 16px;
    color: #333;
}

.card {
    background-color: #fff;
    max-width: 640px;
    margin: 0 auto;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

.card h1 {
    margin-top: 0;
    text-align: center;
}

.lead {
    color: #555;
    text-align: center;
    margin-bottom: 30px;
}

.demo {
    border-top: 1px solid #eee;
    padding-top: 16px;
    margin-bottom: 16px;
}

.demo h2 {
    font-size: 17px;
    margin: 0 0 4px;
}

.demo p {
    color: #666;
    font-size: 14px;
    margin: 0 0 12px;
}

code {
    background-color: #f0f0f0;
    border-radius: 3px;
    padding: 1px 4px;
    font-size: 13px;
}

.button-row {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

button {
    padding: 10px 16px;
    background-color: #007bff;
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
}

button:hover {
    background-color: #0056b3;
}

button.danger {
    background-color: #dc3545;
}

button.danger:hover {
    background-color: #b02a37;
}

.result {
    display: block;
    margin-top: 24px;
    padding: 12px;
    background-color: #f8f9fa;
    border-left: 4px solid #007bff;
    border-radius: 4px;
    font-size: 14px;
    color: #555;
}