body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f4f7f9;
    color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

.container {
    background-color: #fff;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 600px;
}

h1 {
    color: #007bff;
    text-align: center;
    margin-bottom: 10px;
}

p {
    text-align: center;
    margin-bottom: 30px;
    color: #666;
}

input[type="file"] {
    display: block;
    width: 100%;
    padding: 10px;
    margin-bottom: 20px;
    border: 2px dashed #ccc;
    border-radius: 6px;
    cursor: pointer;
}

button {
    width: 100%;
    padding: 12px;
    background-color: #28a745;
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 1.1em;
    cursor: pointer;
    transition: background-color 0.3s;
}

button:hover:not(:disabled) {
    background-color: #218838;
}

button:disabled {
    background-color: #90c69e;
    cursor: not-allowed;
}

#fileList {
    margin-bottom: 20px;
    padding: 10px;
    border: 1px solid #eee;
    background-color: #f9f9f9;
    border-radius: 4px;
}

#fileList ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

#fileList li {
    padding: 5px 0;
    border-bottom: 1px dotted #ddd;
    font-size: 0.9em;
}

#fileList li:last-child {
    border-bottom: none;
}

#statusMessage {
    margin-top: 20px;
    padding: 10px;
    border-radius: 4px;
    font-weight: bold;
    text-align: center;
}

.success {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.error {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.info {
    background-color: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}