/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

/* Utility Classes */
.hidden {
    display: none !important;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Screens */
.screen {
    display: none;
}

.screen.active {
    display: block;
}

/* Login Screen */
.login-container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.login-form {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 400px;
}

.login-form h1 {
    text-align: center;
    margin-bottom: 1.5rem;
    color: #333;
}

/* Change Password Screen */
.change-password-form {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    max-width: 500px;
    margin: 2rem auto;
}

.warning {
    background: #fff3cd;
    color: #856404;
    padding: 0.75rem;
    border: 1px solid #ffeaa7;
    border-radius: 5px;
    margin-bottom: 1rem;
}

/* Form Styles */
.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #555;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 2px rgba(102, 126, 234, 0.25);
}

/* Button Styles */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background: #667eea;
    color: white;
}

.btn-primary:hover {
    background: #5a6fd8;
    transform: translateY(-1px);
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
}

.btn-success {
    background: #28a745;
    color: white;
}

.btn-danger {
    background: #dc3545;
    color: white;
}

.btn-warning {
    background: #ffc107;
    color: #212529;
}

/* Navigation */
.navbar {
    background: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-brand h1 {
    font-size: 1.5rem;
    color: #333;
}

.nav-menu {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: #666;
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    transition: all 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: #667eea;
    background: rgba(102, 126, 234, 0.1);
}

.nav-user {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.nav-user span {
    font-weight: 500;
    color: #333;
}

/* Main Content */
.main-content {
    padding: 2rem 0;
}

.tab-content {
    display: none;
}

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

.tab-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.tab-header h2 {
    color: #333;
    font-size: 2rem;
}

/* Dashboard Stats */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    text-align: center;
}

.stat-card h3 {
    color: #666;
    font-size: 1rem;
    margin-bottom: 1rem;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: bold;
    color: #667eea;
}

.stat-number.overdue {
    color: #dc3545;
}

/* Filters */
.filters {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.filters select {
    padding: 0.5rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    background: white;
}

.admin-filter {
    display: block;
}

.admin-filter.hidden {
    display: none;
}

/* Tables */
.table-container {
    background: white;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    overflow: hidden;
}

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

.data-table thead {
    background: #f8f9fa;
}

.data-table th {
    padding: 1rem;
    text-align: left;
    font-weight: 600;
    color: #333;
    border-bottom: 1px solid #dee2e6;
}

.data-table tbody tr {
    border-bottom: 1px solid #f1f3f4;
}

.data-table tbody tr:hover {
    background: #f8f9fa;
}

.data-table tbody tr:last-child {
    border-bottom: none;
}

.data-table td {
    padding: 1rem;
    vertical-align: middle;
}

/* Status and Priority Badges */
.status-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
}

.status-pending { background: #fff3cd; color: #856404; }
.status-in_progress { background: #d1ecf1; color: #0c5460; }
.status-completed { background: #d4edda; color: #155724; }
.status-cancelled { background: #f8d7da; color: #721c24; }

.priority-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
}

.priority-low { background: #e8f5e8; color: #2d5a2d; }
.priority-medium { background: #fff3cd; color: #856404; }
.priority-high { background: #f8d7da; color: #721c24; }
.priority-urgent { background: #f8d7da; color: #721c24; font-weight: bold; }

/* Table Actions */
.table-actions {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.table-actions .btn {
    padding: 0.25rem 0.75rem;
    font-size: 0.875rem;
}

/* Pagination */
.pagination {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background: #f8f9fa;
    border-top: 1px solid #dee2e6;
}

.pagination-info {
    color: #666;
    font-size: 0.875rem;
}

.pagination-controls {
    display: flex;
    gap: 0.5rem;
}

.pagination-btn {
    padding: 0.5rem 1rem;
    border: 1px solid #dee2e6;
    background: white;
    color: #333;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.pagination-btn:hover:not(:disabled) {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

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

.pagination-btn.active {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

/* Modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: white;
    border-radius: 10px;
    max-width: 90vw;
    max-height: 90vh;
    overflow-y: auto;
    transform: scale(0.9);
    transition: transform 0.3s ease;
}

.modal-overlay.active .modal-content {
    transform: scale(1);
}

.modal-header {
    padding: 1.5rem;
    border-bottom: 1px solid #dee2e6;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: #666;
}

/* Messages */
.error-message {
    background: #f8d7da;
    color: #721c24;
    padding: 0.75rem;
    border: 1px solid #f5c6cb;
    border-radius: 5px;
    margin-bottom: 1rem;
    display: none;
}

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

.success-message {
    background: #d4edda;
    color: #155724;
    padding: 0.75rem;
    border: 1px solid #c3e6cb;
    border-radius: 5px;
    margin-bottom: 1rem;
    display: none;
}

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

/* Loading */
.loading {
    text-align: center;
    padding: 2rem;
    color: #666;
}

/* Statistics */
.statistics-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.statistics-controls {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.statistics-controls .form-control {
    padding: 0.5rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    background: white;
}

.statistics-section {
    margin-bottom: 2rem;
}

.stats-overview-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.stats-card {
    background: white;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    overflow: hidden;
}

.stats-card-header {
    background: #f8f9fa;
    padding: 1rem 1.5rem;
    border-bottom: 1px solid #dee2e6;
}

.stats-card-header h3 {
    margin: 0;
    color: #333;
}

.stats-card-content {
    padding: 1.5rem;
}

.stats-metrics {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.stat-metric {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.metric-label {
    font-size: 0.875rem;
    color: #666;
    margin-bottom: 0.5rem;
}

.metric-value {
    font-size: 1.5rem;
    font-weight: bold;
    color: #333;
}

.metric-value.overdue {
    color: #dc3545;
}

.stats-progress {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.progress-item {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.progress-label {
    min-width: 120px;
    font-size: 0.875rem;
    color: #666;
}

.progress-bar {
    flex: 1;
    height: 8px;
    background: #e9ecef;
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: #667eea;
    transition: width 0.3s ease;
}

.progress-value {
    min-width: 50px;
    text-align: right;
    font-size: 0.875rem;
    font-weight: 600;
    color: #333;
}

/* Admin Tabs */
.admin-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    border-bottom: 1px solid #dee2e6;
    overflow-x: auto;
}

.admin-tab-btn {
    padding: 0.75rem 1.5rem;
    border: none;
    background: none;
    color: #666;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.admin-tab-btn:hover {
    color: #667eea;
}

.admin-tab-btn.active {
    color: #667eea;
    border-bottom-color: #667eea;
}

.admin-tab-content {
    display: none;
}

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

.admin-section {
    background: white;
    border-radius: 10px;
    padding: 2rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin-bottom: 2rem;
}

.admin-section:last-child {
    margin-bottom: 0;
}

/* Mobile Menu */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background: #333;
    margin: 3px 0;
    transition: 0.3s;
}

/* Mobile Bottom Navigation */
.mobile-bottom-nav {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: white;
    border-top: 1px solid #dee2e6;
    padding: 0.5rem 0;
    z-index: 1000;
}

.bottom-nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-decoration: none;
    color: #666;
    font-size: 0.75rem;
    padding: 0.5rem;
    flex: 1;
    transition: color 0.3s ease;
}

.bottom-nav-item:hover {
    color: #667eea;
}

.bottom-nav-item.active {
    color: #667eea;
}

.nav-icon {
    font-size: 1.5rem;
    margin-bottom: 0.25rem;
}

.nav-label {
    font-size: 0.75rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-container {
        padding: 0 1rem;
    }
    
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 1rem;
        box-shadow: 0 2px 10px rgba(0,0,0,0.1);
        transform: translateY(-100%);
        transition: transform 0.3s ease;
        z-index: 999;
    }
    
    .nav-menu.active {
        transform: translateY(0);
    }
    
    .nav-link {
        padding: 0.75rem 1rem;
        border-radius: 5px;
    }
    
    .nav-user {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .nav-container {
        padding: 0 1rem;
    }
    
    .nav-brand h1 {
        font-size: 1.25rem;
    }
    
    .admin-tabs {
        flex-direction: column;
        gap: 0;
    }
    
    .admin-tab-btn {
        border-bottom: 1px solid #dee2e6;
        border-radius: 0;
    }
    
    .mobile-bottom-nav {
        display: flex;
    }
    
    .main-content {
        padding-bottom: 80px;
    }
    
    .container {
        padding: 0 1rem;
    }
    
    .table-container {
        overflow-x: auto;
    }
    
    .data-table {
        min-width: 600px;
    }
    
    .dashboard-tables {
        grid-template-columns: 1fr;
    }
    
    .section-header {
        flex-direction: column;
        gap: 1rem;
        align-items: flex-start;
    }
    
    .section-header h3 {
        margin: 0;
    }
    
    .dashboard-section .data-table {
        min-width: 500px;
    }
}

@media (max-width: 480px) {
    .bottom-nav-item {
        padding: 0.25rem;
    }
    
    .nav-icon {
        font-size: 1.25rem;
    }
    
    .nav-label {
        font-size: 0.625rem;
    }
    
    .container {
        padding: 0 0.5rem;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .stat-card {
        padding: 1rem;
    }
    
    .stat-card h3 {
        font-size: 0.875rem;
    }
    
    .stat-number {
        font-size: 2rem;
    }
}

/* Loading Spinner */
.loading-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 3rem;
    color: #666;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #f3f3f3;
    border-top: 4px solid #667eea;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 3rem;
    color: #666;
}

.empty-state i {
    font-size: 3rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state h3 {
    margin-bottom: 0.5rem;
    color: #333;
}

.empty-state p {
    color: #666;
}

/* Webhook and Zalo Settings */
.webhook-settings,
.zalo-settings {
    max-width: 600px;
}

.webhook-settings .form-group,
.zalo-settings .form-group {
    margin-bottom: 1.5rem;
}

.webhook-settings label,
.zalo-settings label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #333;
}

.webhook-settings input[type="url"],
.webhook-settings input[type="text"],
.zalo-settings input[type="text"],
.zalo-settings input[type="password"] {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1rem;
}

.webhook-settings .checkbox-label,
.zalo-settings .checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
}

.webhook-settings .checkbox-label input[type="checkbox"],
.zalo-settings .checkbox-label input[type="checkbox"] {
    width: auto;
}

/* Users and Departments Lists */
.users-list,
.departments-list {
    display: grid;
    gap: 1rem;
}

.user-item,
.department-item {
    background: white;
    border: 1px solid #dee2e6;
    border-radius: 8px;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.3s ease;
}

.user-item:hover,
.department-item:hover {
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.user-header,
.department-header {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.user-name,
.department-name {
    font-weight: 600;
    color: #333;
}

.user-meta,
.department-meta {
    display: flex;
    gap: 1rem;
    font-size: 0.875rem;
    color: #666;
}

.user-meta span,
.department-meta span {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.user-actions,
.department-actions {
    display: flex;
    gap: 0.5rem;
}

.user-actions .btn,
.department-actions .btn {
    padding: 0.25rem 0.75rem;
    font-size: 0.875rem;
}