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

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --secondary-hover: #475569;
    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --border-color: #e2e8f0;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    color: var(--text-primary);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

header {
    text-align: center;
    color: white;
    margin-bottom: 20px;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Navigation Tabs */
.tabs {
    display: flex;
    gap: 5px;
    margin-bottom: 20px;
    background: rgba(255, 255, 255, 0.2);
    padding: 5px;
    border-radius: 12px;
}

.tab-btn {
    flex: 1;
    padding: 12px 20px;
    border: none;
    background: transparent;
    color: white;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: 8px;
    transition: all 0.2s;
}

.tab-btn:hover {
    background: rgba(255, 255, 255, 0.2);
}

.tab-btn.active {
    background: white;
    color: var(--primary-color);
    box-shadow: var(--shadow);
}

/* Tab Content */
.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

main section {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 30px;
    box-shadow: var(--shadow-lg);
}

section h2 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: var(--text-primary);
}

.section-description {
    color: var(--text-secondary);
    margin-bottom: 20px;
    font-size: 0.95rem;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
    margin-bottom: 10px;
}

.header-actions {
    display: flex;
    gap: 10px;
}

/* Buttons */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow);
}

.btn-secondary {
    background: var(--secondary-color);
    color: white;
}

.btn-secondary:hover:not(:disabled) {
    background: var(--secondary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow);
}

.btn-danger {
    background: var(--error-color);
    color: white;
}

.btn-danger:hover:not(:disabled) {
    background: #dc2626;
}

.btn-small {
    padding: 6px 12px;
    font-size: 0.85rem;
}

.btn-large {
    padding: 16px 32px;
    font-size: 1.1rem;
}

.upload-controls {
    display: flex;
    gap: 15px;
    margin-top: 20px;
    justify-content: center;
}

/* Drop Zone */
.drop-zone {
    border: 3px dashed var(--border-color);
    border-radius: 12px;
    padding: 60px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    background: var(--bg-color);
}

.drop-zone:hover {
    border-color: var(--primary-color);
    background: #f1f5f9;
}

.drop-zone.dragover {
    border-color: var(--primary-color);
    background: #eff6ff;
    transform: scale(1.02);
}

.drop-zone-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

.drop-zone-content svg {
    color: var(--primary-color);
}

.drop-zone-text {
    font-size: 1.2rem;
    font-weight: 500;
    color: var(--text-primary);
}

.drop-zone-hint {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* File List */
.file-list {
    margin-top: 20px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
    background: var(--bg-color);
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.file-item-info {
    display: flex;
    align-items: center;
    gap: 12px;
    flex: 1;
}

.file-item-name {
    font-weight: 500;
    color: var(--text-primary);
}

.file-item-size {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.file-item-remove {
    background: var(--error-color);
    color: white;
    border: none;
    border-radius: 6px;
    padding: 6px 12px;
    cursor: pointer;
    font-size: 0.85rem;
    transition: background 0.2s;
}

.file-item-remove:hover {
    background: #dc2626;
}

/* Password Manager */
.password-controls {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

#passwordTextarea {
    width: 100%;
    padding: 12px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    resize: vertical;
    transition: border-color 0.2s;
}

#passwordTextarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.button-group {
    display: flex;
    gap: 10px;
}

/* Status Messages */
.status-message {
    padding: 12px;
    border-radius: 8px;
    font-size: 0.9rem;
    display: none;
    margin-bottom: 15px;
}

.status-message.show {
    display: block;
}

.status-message.success {
    background: #d1fae5;
    color: #065f46;
    border: 1px solid #10b981;
}

.status-message.error {
    background: #fee2e2;
    color: #991b1b;
    border: 1px solid #ef4444;
}

.status-message.info {
    background: #dbeafe;
    color: #1e40af;
    border: 1px solid #3b82f6;
}

/* Results */
.results-section {
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}

.results-section h3 {
    margin-bottom: 15px;
}

.results-container {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.result-item {
    padding: 20px;
    border-radius: 8px;
    border: 2px solid var(--border-color);
    background: var(--bg-color);
}

.result-item.success {
    border-color: var(--success-color);
    background: #d1fae5;
}

.result-item.error {
    border-color: var(--error-color);
    background: #fee2e2;
}

.result-item.warning {
    border-color: var(--warning-color);
    background: #fef3c7;
}

.result-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 10px;
}

.result-filename {
    font-weight: 600;
    font-size: 1.1rem;
}

.result-status {
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    text-transform: uppercase;
}

.result-status.success {
    background: var(--success-color);
    color: white;
}

.result-status.error {
    background: var(--error-color);
    color: white;
}

.result-status.warning {
    background: var(--warning-color);
    color: white;
}

.result-message {
    margin: 8px 0;
    color: var(--text-primary);
}

.result-details {
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--border-color);
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.result-details strong {
    color: var(--text-primary);
}

/* Clients Table */
.clients-table-container {
    overflow-x: auto;
}

.clients-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 15px;
}

.clients-table th,
.clients-table td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.clients-table th {
    background: var(--bg-color);
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    font-size: 0.85rem;
}

.clients-table tbody tr:hover {
    background: var(--bg-color);
}

.color-swatch {
    width: 24px;
    height: 24px;
    border-radius: 4px;
    border: 1px solid var(--border-color);
    display: inline-block;
}

.synced-badge {
    padding: 4px 8px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 500;
}

.synced-badge.yes {
    background: #d1fae5;
    color: #065f46;
}

.synced-badge.no {
    background: #fee2e2;
    color: #991b1b;
}

.action-buttons {
    display: flex;
    gap: 8px;
}

.no-clients {
    text-align: center;
    padding: 40px;
    color: var(--text-secondary);
    display: none;
}

.no-clients.show {
    display: block;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    justify-content: center;
    align-items: center;
}

.modal.show {
    display: flex;
}

.modal-content {
    background: white;
    border-radius: 12px;
    width: 100%;
    max-width: 500px;
    margin: 20px;
    box-shadow: var(--shadow-lg);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h3 {
    margin: 0;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-secondary);
    transition: color 0.2s;
}

.modal-close:hover {
    color: var(--text-primary);
}

#clientForm {
    padding: 20px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-primary);
}

.form-group input[type="text"] {
    width: 100%;
    padding: 12px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s;
}

.form-group input[type="text"]:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group small {
    display: block;
    margin-top: 5px;
    color: var(--text-secondary);
    font-size: 0.85rem;
}

.color-input-group {
    display: flex;
    gap: 10px;
    align-items: center;
}

.color-input-group input[type="color"] {
    width: 50px;
    height: 40px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
}

.color-input-group input[type="text"] {
    flex: 1;
}

.modal-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
    padding-top: 10px;
    border-top: 1px solid var(--border-color);
    margin-top: 10px;
}

/* Loading Spinner */
.spinner {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* User Guide */
.guide-content {
    max-width: 800px;
}

.guide-section {
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
}

.guide-section:last-child {
    border-bottom: none;
}

.guide-section h3 {
    color: var(--primary-color);
    margin-bottom: 15px;
    font-size: 1.2rem;
}

.guide-section p {
    color: var(--text-primary);
    line-height: 1.6;
    margin-bottom: 10px;
}

.guide-section ol,
.guide-section ul {
    padding-left: 25px;
    margin-bottom: 15px;
}

.guide-section li {
    margin-bottom: 8px;
    line-height: 1.5;
    color: var(--text-primary);
}

.guide-tip {
    background: #dbeafe;
    border-left: 4px solid var(--primary-color);
    padding: 12px 15px;
    border-radius: 0 8px 8px 0;
    margin-top: 15px;
}

.code-block {
    display: block;
    background: var(--bg-color);
    padding: 12px 15px;
    border-radius: 8px;
    font-family: 'Courier New', monospace;
    margin: 10px 0;
    border: 1px solid var(--border-color);
}

.guide-section code:not(.code-block) {
    background: var(--bg-color);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
}

.guide-faq {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.faq-item {
    background: var(--bg-color);
    padding: 15px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.faq-item strong {
    display: block;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.faq-item p {
    margin: 0;
    color: var(--text-secondary);
}

/* Footer */
footer {
    text-align: center;
    color: white;
    margin-top: 40px;
}

footer p {
    margin: 5px 0;
}

footer .signature {
    font-size: 0.85rem;
    opacity: 0.9;
}

footer a {
    color: #fbbf24;
    text-decoration: none;
    transition: color 0.2s;
}

footer a:hover {
    color: #fcd34d;
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }

    .tabs {
        flex-direction: column;
    }

    main section {
        padding: 20px;
    }

    .section-header {
        flex-direction: column;
        align-items: stretch;
    }

    .header-actions {
        justify-content: stretch;
    }

    .header-actions .btn {
        flex: 1;
    }

    .button-group {
        flex-direction: column;
    }

    .upload-controls {
        flex-direction: column;
    }

    .file-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }

    .clients-table th,
    .clients-table td {
        padding: 8px 10px;
        font-size: 0.85rem;
    }

    .action-buttons {
        flex-direction: column;
    }
}