/* Mobile-first design */
body {
    font-family: Arial, sans-serif;
    background-color: #f9f9f9;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 400px;
    background-color: #ffffff;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    padding: 20px;
    box-sizing: border-box;
    text-align: center;
    margin: 15px;
}

header {
    background-color: #007bff;
    color: #fff;
    padding: 15px;
    border-radius: 8px 8px 0 0;
    font-size: 22px;
}

footer {
    background-color: #007bff;
    color: #fff;
    padding: 10px;
    border-radius: 0 0 8px 8px;
    margin-top: 20px;
    font-size: 14px;
}

form {
    margin-top: 20px;
}

label {
    font-weight: bold;
    font-size: 16px;
    margin-bottom: 10px;
    display: block;
}

textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
    margin-bottom: 20px;
    box-sizing: border-box;
    resize: vertical;
}

button {
    width: 100%;
    padding: 12px;
    background-color: #28a745;
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    transition: background-color 0.3s, transform 0.2s;
}

button:hover {
    background-color: #218838;
    transform: scale(1.05);
}

.qr-result {
    margin-top: 30px;
    background-color: #f9f9f9;
    border: 1px solid #ddd;
    border-radius: 4px;
    padding: 20px;
}

.qr-result img {
    max-width: 100%;
    height: auto;
    margin-top: 10px;
}

.download-button {
    display: block;
    padding: 12px;
    background-color: #28a745;
    color: white;
    border-radius: 4px;
    text-decoration: none;
    font-size: 16px;
    margin-top: 10px;
    transition: background-color 0.3s;
}

.download-button:hover {
    background-color: #218838;
}

/* Larger screen adjustments */
@media (min-width: 769px) {
    .container {
        max-width: 600px;
        padding: 30px;
    }

    header {
        font-size: 26px;
    }

    button, label, textarea {
        font-size: 18px;
    }

    .download-button {
        font-size: 18px;
    }
}