body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: #f4f4f9;
    color: #333;
    display: flex;
    justify-content: center;
    padding: 20px;
}

.container {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 600px;
}

h1 {
    text-align: center;
    margin-bottom: 0.5rem;
}

p {
    text-align: center;
    color: #666;
    margin-bottom: 2rem;
}

.upload-section {
    text-align: center;
    margin-bottom: 20px;
}

input[type="file"] {
    display: none;
}

.btn {
    display: inline-block;
    padding: 10px 20px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    text-decoration: none;
    transition: background 0.3s;
}

.btn:hover {
    background-color: #0056b3;
}

.btn:disabled {
    background-color: #ccc;
    cursor: not-allowed;
}

.btn-primary {
    width: 100%;
    font-weight: bold;
    font-size: 1.1rem;
}

.file-list {
    margin-bottom: 20px;
    border: 1px solid #ddd;
    border-radius: 4px;
    max-height: 300px;
    overflow-y: auto;
}

.file-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px;
    border-bottom: 1px solid #eee;
    background: #fff;
}

.file-item:last-child {
    border-bottom: none;
}

.file-name {
    flex-grow: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-right: 10px;
}

.controls button {
    background: none;
    border: 1px solid #ddd;
    border-radius: 4px;
    cursor: pointer;
    padding: 2px 8px;
    margin-left: 2px;
}

.controls button:hover {
    background: #eee;
}

.message {
    margin-top: 15px;
    text-align: center;
    font-weight: bold;
    white-space: pre-wrap;
}