body {
    background-color: #173464;
}

.container {
    background-color: #ffffff;
    padding: 20px 40px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    max-width: 600px;
    width: 100%;
    margin: 20px auto;
}

h1 {
    text-align: center;
    color: #333333;
    margin-bottom: 20px;
}

button {
    background-color: #4CAF50;
    color: white;
    padding: 10px 15px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    width: 100%;
}

button:hover {
    background-color: #45a049;
}

#preview {
    display: none;
    margin-top: 10px;
    max-width: 100%;
    height: auto;
    border: 2px solid #4CAF50;
    border-radius: 4px;
}