* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1300px;
    margin: 0 auto;
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.1);
    overflow: hidden;
}

header {
    background: #2c3e50;
    color: white;
    padding: 30px;
    text-align: center;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 10px;
}

.logo i {
    font-size: 48px;
}

.logo h1 {
    font-size: 28px;
}

.subtitle {
    font-size: 16px;
    opacity: 0.9;
}

.alert {
    background: #f39c12;
    color: #2c3e50;
    padding: 10px;
    border-radius: 8px;
    margin-top: 20px;
    font-size: 14px;
}

.upload-section, .files-section {
    padding: 30px;
    border-bottom: 1px solid #e0e0e0;
}

.upload-section h2, .files-section h2 {
    color: #2c3e50;
    margin-bottom: 20px;
    font-size: 22px;
}

.file-input-wrapper {
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 15px;
}

#fileInput {
    display: none;
}

.custom-file-label {
    background: #3498db;
    color: white;
    padding: 10px 20px;
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.3s;
}

.custom-file-label:hover {
    background: #2980b9;
}

#fileName {
    color: #7f8c8d;
}

.btn {
    border: none;
    padding: 12px 30px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 16px;
    transition: all 0.3s;
}

.btn-primary {
    background: #27ae60;
    color: white;
}

.btn-primary:hover {
    background: #229954;
}

.table-responsive {
    overflow-x: auto;
}

.files-table {
    width: 100%;
    border-collapse: collapse;
}

.files-table th {
    background: #ecf0f1;
    padding: 12px;
    text-align: left;
    font-weight: 600;
    color: #2c3e50;
}

.files-table td {
    padding: 12px;
    border-bottom: 1px solid #ecf0f1;
}

.files-table tr:hover {
    background: #f9f9f9;
}

.file-icon {
    margin-right: 8px;
    color: #3498db;
}

.actions a {
    display: inline-block;
    margin-right: 10px;
    padding: 6px 12px;
    text-decoration: none;
    border-radius: 4px;
    font-size: 13px;
    transition: 0.2s;
}

.btn-download {
    background: #3498db;
    color: white;
}

.btn-download:hover {
    background: #2980b9;
}

.btn-open {
    background: #95a5a6;
    color: white;
}

.btn-open:hover {
    background: #7f8c8d;
}

.btn-qrcode {
    background: #e67e22;
    color: white;
}

.btn-qrcode:hover {
    background: #d35400;
}

.qr-exists {
    color: #27ae60;
    margin-left: 5px;
}

.empty-state {
    text-align: center;
    padding: 50px;
    color: #7f8c8d;
}

.empty-state i {
    font-size: 64px;
    margin-bottom: 20px;
}

@media (max-width: 768px) {
    .actions a {
        display: block;
        margin-bottom: 8px;
        text-align: center;
    }
    
    .file-input-wrapper {
        flex-direction: column;
        align-items: flex-start;
    }
}