body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    text-align: center;
    background-color: #e9ecef;
    padding: 30px;
    margin: 0;
}
.container {
    max-width: 600px;
    margin: 0 auto;
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 10px 15px rgba(0,0,0,0.1);
}
input[type="file"] {
    margin: 20px 0;
}
button {
    background-color: #007bff;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
}
button:disabled {
    background-color: #ccc;
    cursor: not-allowed;
}
canvas {
    max-width: 100%;
    margin-top: 20px;
    border: 1px dashed #aaa;
    border-radius: 8px;
}