body {
    font-family: Arial, Helvetica, sans-serif;
    background: #f4f6f9;
    margin: 0;
}
header, footer {
    background: #003366;
    color: white;
    padding: 20px;
}
main {
    max-width: 900px;
    margin: 30px auto;
    background: white;
    padding: 30px;
    border-radius: 8px;
}
button {
    padding: 10px 20px;
    background: #0059b3;
    color: white;
    border: none;
    cursor: pointer;
}
button:hover {
    background: #003f80;
}
pre {
    background: #eef5ff;
    padding: 20px;
    white-space: pre-wrap;
    border-left: 5px solid #0059b3;
}
#loading {
    display: none;
    margin-top: 15px;
    font-weight: bold;
}