/* ============================================================
   TKB Theme & Responsive Styles (2026)
   Modern UI with Dark Mode and Mobile Support
   ============================================================ */

:root {
    --primary-color: #3b82f6;
    --primary-light: #60a5fa;
    --primary-dark: #1d4ed8;
    --danger-color: #ef4444;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --info-color: #06b6d4;

    --bg-light: #f8fafc;
    --bg-white: #ffffff;
    --text-dark: #0f172a;
    --text-gray: #64748b;
    --border-light: #e2e8f0;

    --bg-dark: #0f172a;
    --bg-dark-secondary: #1e293b;
    --bg-dark-tertiary: #334155;
    --text-light: #f1f5f9;
    --text-light-gray: #cbd5e1;
}

/* ============================================================
   Light Mode (Default)
   ============================================================ */

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg-light);
    color: var(--text-dark);
    font-family: 'Noto Sans', 'Noto Sans Vietnamese', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--primary-dark);
}

/* Cards */
.card {
    border: none;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    border-radius: 12px;
    transition: all 0.3s ease;
    background: white;
    overflow: hidden;
}

.card:hover {
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.12);
    transform: translateY(-4px);
}

.card-header {
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    border-bottom: 1px solid var(--border-light);
    border-radius: 12px 12px 0 0;
    padding: 1.25rem;
    font-weight: 600;
    color: var(--text-dark);
}

.card-body {
    padding: 1.5rem;
}

.card-footer {
    background-color: #f8fafc;
    border-top: 1px solid var(--border-light);
    padding: 1rem 1.5rem;
}

/* Tables */
.table {
    margin-bottom: 0;
    border-collapse: separate;
    border-spacing: 0;
}

.table thead th {
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    border-bottom: 2px solid var(--border-light);
    border-color: var(--border-light);
    font-weight: 700;
    color: var(--text-dark);
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.8px;
    padding: 1rem 0.75rem;
}

.table tbody tr {
    transition: all 0.2s ease;
    border-bottom: 1px solid var(--border-light);
}

.table tbody tr:hover {
    background-color: #f8fafc;
}

.table-striped tbody tr:nth-of-type(odd) {
    background-color: rgba(59, 130, 246, 0.02);
}

.table td {
    padding: 0.875rem 0.75rem;
    vertical-align: middle;
}

/* Forms */
.form-control,
.form-select {
    border: 2px solid var(--border-light);
    border-radius: 8px;
    padding: 0.75rem 1rem;
    transition: all 0.3s ease;
    font-size: 0.95rem;
    background-color: #f8fafc;
}

.form-control:focus,
.form-select:focus {
    border-color: var(--primary-color);
    background-color: white;
    box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.1);
    outline: none;
}

.form-control::placeholder {
    color: #94a3b8;
}

.form-control:disabled,
.form-select:disabled {
    background-color: #f1f5f9;
    color: #cbd5e1;
    cursor: not-allowed;
}

.form-label {
    font-weight: 500;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.form-group {
    margin-bottom: 1rem;
}

/* Buttons */
.btn {
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s ease;
    padding: 0.625rem 1.25rem;
    font-size: 0.95rem;
    border: none;
    cursor: pointer;
    letter-spacing: 0.3px;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:active::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.3);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary-color) 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(59, 130, 246, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background: linear-gradient(135deg, #64748b 0%, #475569 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(100, 116, 139, 0.2);
}

.btn-secondary:hover {
    background: linear-gradient(135deg, #475569 0%, #334155 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(100, 116, 139, 0.3);
}

.btn-danger {
    background: linear-gradient(135deg, var(--danger-color) 0%, #f87171 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(239, 68, 68, 0.3);
}

.btn-danger:hover {
    background: linear-gradient(135deg, #dc2626 0%, var(--danger-color) 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(239, 68, 68, 0.4);
}

.btn-success {
    background: linear-gradient(135deg, var(--success-color) 0%, #34d399 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3);
}

.btn-success:hover {
    background: linear-gradient(135deg, #059669 0%, var(--success-color) 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(16, 185, 129, 0.4);
}

.btn-warning {
    background: linear-gradient(135deg, var(--warning-color) 0%, #fbbf24 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(245, 158, 11, 0.3);
}

.btn-warning:hover {
    background: linear-gradient(135deg, #d97706 0%, var(--warning-color) 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(245, 158, 11, 0.4);
}

.btn-info {
    background: linear-gradient(135deg, var(--info-color) 0%, #22d3ee 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(6, 182, 212, 0.3);
}

.btn-info:hover {
    background: linear-gradient(135deg, #0891b2 0%, var(--info-color) 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(6, 182, 212, 0.4);
}

.btn-link {
    color: var(--primary-color);
    text-decoration: none;
    background: transparent;
    box-shadow: none;
    font-weight: 500;
}

.btn-link:hover {
    color: var(--primary-dark);
    background: transparent;
}

.btn-outline-primary {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    box-shadow: none;
}

.btn-outline-primary:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(59, 130, 246, 0.3);
}

.btn-block {
    width: 100%;
    display: block;
}

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: 0.85rem;
}

.btn-lg {
    padding: 0.75rem 1.5rem;
    font-size: 1.1rem;
}

/* Alerts */
.alert {
    border-radius: 8px;
    border: 1px solid;
    padding: 1rem;
    margin-bottom: 1rem;
}

.alert-primary {
    background-color: #dbeafe;
    border-color: #93c5fd;
    color: #1e40af;
}

.alert-success {
    background-color: #d1fae5;
    border-color: #6ee7b7;
    color: #065f46;
}

.alert-warning {
    background-color: #fef3c7;
    border-color: #fcd34d;
    color: #92400e;
}

.alert-danger {
    background-color: #fee2e2;
    border-color: #fca5a5;
    color: #7f1d1d;
}

/* Badges */
.badge {
    padding: 0.35rem 0.65rem;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 500;
}

.badge-primary {
    background-color: #dbeafe;
    color: #1e40af;
}

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

.badge-warning {
    background-color: #fef3c7;
    color: #92400e;
}

.badge-danger {
    background-color: #fee2e2;
    color: #7f1d1d;
}

/* Modals */
.modal-content {
    border: none;
    border-radius: 16px;
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.15);
    overflow: hidden;
}

.modal-header {
    border-bottom: 1px solid var(--border-light);
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    padding: 1.5rem;
}

.modal-title {
    font-weight: 600;
    color: var(--text-dark);
    font-size: 1.25rem;
}

.modal-body {
    padding: 1.5rem;
    background-color: white;
}

.modal-footer {
    border-top: 1px solid var(--border-light);
    background-color: #f8fafc;
    padding: 1rem 1.5rem;
}

/* Pagination */
.pagination {
    margin: 1rem 0;
}

.page-link {
    border: 1px solid var(--border-light);
    color: var(--primary-color);
    border-radius: 6px;
    margin: 0 2px;
}

.page-link:hover {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.page-item.active .page-link {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

/* ============================================================
   Dark Mode
   ============================================================ */

body.dark-mode {
    background-color: var(--bg-dark);
    color: var(--text-light);
}

body.dark-mode a {
    color: #60a5fa;
}

body.dark-mode a:hover {
    color: #93c5fd;
}

body.dark-mode .card {
    background-color: var(--bg-dark-secondary);
    border-color: var(--bg-dark-tertiary);
}

body.dark-mode .card:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
}

body.dark-mode .card-header {
    background-color: var(--bg-dark-tertiary);
    border-bottom-color: var(--bg-dark-tertiary);
}

body.dark-mode .table {
    color: var(--text-light);
}

body.dark-mode .table thead th {
    background-color: #111827;
    border-color: var(--bg-dark-tertiary);
    color: var(--text-light-gray);
}

body.dark-mode .table tbody tr:hover {
    background-color: var(--bg-dark-tertiary);
}

body.dark-mode .table-striped tbody tr:nth-of-type(odd) {
    background-color: rgba(255, 255, 255, 0.05);
}

body.dark-mode .form-control,
body.dark-mode .form-select {
    background-color: var(--bg-dark-tertiary);
    border-color: #4b5563;
    color: var(--text-light);
}

body.dark-mode .form-control::placeholder {
    color: var(--text-light-gray);
}

body.dark-mode .form-label {
    color: var(--text-light);
}

body.dark-mode .form-control:focus,
body.dark-mode .form-select:focus {
    border-color: #60a5fa;
    box-shadow: 0 0 0 3px rgba(96, 165, 250, 0.1);
}

body.dark-mode .alert-primary {
    background-color: #1e3a8a;
    border-color: #1e40af;
    color: #93c5fd;
}

body.dark-mode .alert-success {
    background-color: #064e3b;
    border-color: #047857;
    color: #86efac;
}

body.dark-mode .alert-warning {
    background-color: #78350f;
    border-color: #92400e;
    color: #fcd34d;
}

body.dark-mode .alert-danger {
    background-color: #7f1d1d;
    border-color: #991b1b;
    color: #fca5a5;
}

body.dark-mode .badge-primary {
    background-color: rgba(96, 165, 250, 0.2);
    color: #93c5fd;
}

body.dark-mode .badge-success {
    background-color: rgba(16, 185, 129, 0.2);
    color: #86efac;
}

body.dark-mode .badge-warning {
    background-color: rgba(251, 146, 60, 0.2);
    color: #fcd34d;
}

body.dark-mode .badge-danger {
    background-color: rgba(239, 68, 68, 0.2);
    color: #fca5a5;
}

body.dark-mode .modal-content {
    background-color: var(--bg-dark-secondary);
    border-color: var(--bg-dark-tertiary);
    color: var(--text-light);
}

body.dark-mode .modal-header {
    border-bottom-color: var(--bg-dark-tertiary);
    background-color: var(--bg-dark-tertiary);
}

body.dark-mode .modal-title {
    color: var(--text-light);
}

body.dark-mode .close {
    color: var(--text-light);
}

body.dark-mode .page-link {
    border-color: var(--bg-dark-tertiary);
    color: #60a5fa;
}

body.dark-mode .page-link:hover {
    background-color: #60a5fa;
    color: #111827;
    border-color: #60a5fa;
}

body.dark-mode .page-item.active .page-link {
    background-color: #60a5fa;
    border-color: #60a5fa;
    color: #111827;
}

/* ============================================================
   Mobile Responsiveness
   ============================================================ */

@media (max-width: 768px) {
    .container-fluid {
        flex-direction: column;
    }
    
    .modern-sidebar {
        position: fixed !important;
        left: -240px;
        width: 240px;
        min-width: 240px;
        max-width: 240px;
        height: 100vh;
        box-shadow: 2px 0 15px rgba(0, 0, 0, 0.2);
        z-index: 1035;
        transition: left 0.3s ease;
        top: 56px;
    }
    
    .modern-sidebar.collapsed {
        left: 0;
    }
    
    .modern-main-content {
        padding: 1rem !important;
        width: 100%;
        margin-left: 0 !important;
    }
    
    /* Hide text on small screens */
    .modern-sidebar .nav-link span {
        font-size: 0.9rem;
    }
    
    /* Reduce padding on mobile */
    .card {
        margin-bottom: 1rem;
    }
    
    .table {
        font-size: 0.85rem;
    }
    
    .btn {
        padding: 0.4rem 0.8rem;
        font-size: 0.85rem;
    }
    
    /* Reduce modal size on mobile */
    .modal-lg {
        max-width: 95vw;
    }
    
    /* Stack grid columns on mobile */
    .row > [class*='col-'] {
        flex-basis: 100%;
        max-width: 100%;
    }
}

@media (min-width: 769px) {
    .modern-sidebar {
        position: sticky !important;
        left: auto !important;
        top: 56px;
        height: calc(100vh - 56px);
    }
}

/* ============================================================
   Utility Classes
   ============================================================ */

.shadow-sm {
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1) !important;
}

.shadow-md {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1) !important;
}

.shadow-lg {
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15) !important;
}

body.dark-mode .shadow-sm {
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.5) !important;
}

body.dark-mode .shadow-md {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5) !important;
}

body.dark-mode .shadow-lg {
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.7) !important;
}

/* Text utilities for dark mode */
body.dark-mode .text-dark {
    color: var(--text-light) !important;
}

body.dark-mode .text-muted {
    color: var(--text-light-gray) !important;
}

body.dark-mode .text-white {
    color: #111827 !important;
}

/* Background utilities for dark mode */
body.dark-mode .bg-light {
    background-color: var(--bg-dark-secondary) !important;
}

body.dark-mode .bg-white {
    background-color: var(--bg-dark-secondary) !important;
}

/* Border utilities for dark mode */
body.dark-mode .border {
    border-color: var(--bg-dark-tertiary) !important;
}

/* ============================================================
   Animations
   ============================================================ */

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.fade-in {
    animation: fadeIn 0.3s ease;
}

.slide-in {
    animation: slideIn 0.3s ease;
}

/* Smooth scrollbar for dark mode */
body.dark-mode ::-webkit-scrollbar {
    width: 8px;
}

body.dark-mode ::-webkit-scrollbar-track {
    background: var(--bg-dark-secondary);
}

body.dark-mode ::-webkit-scrollbar-thumb {
    background: var(--bg-dark-tertiary);
    border-radius: 4px;
}

body.dark-mode ::-webkit-scrollbar-thumb:hover {
    background: #4b5563;
}

/* ============================================================
   Bootstrap 4 Utility Classes (for BS3 compatibility)
   ============================================================ */
.d-flex { display: flex !important; }
.d-none { display: none !important; }
.d-block { display: block !important; }
.d-inline { display: inline !important; }
.d-inline-block { display: inline-block !important; }
@media (min-width: 768px) {
    .d-md-block { display: block !important; }
    .d-md-none { display: none !important; }
    .d-md-inline { display: inline !important; }
    .d-md-flex { display: flex !important; }
}
.flex-column { flex-direction: column !important; }
.flex-row { flex-direction: row !important; }
.flex-shrink-0 { flex-shrink: 0 !important; }
.flex-wrap { flex-wrap: wrap !important; }
.align-items-center { align-items: center !important; }
.align-items-start { align-items: flex-start !important; }
.align-items-end { align-items: flex-end !important; }
.justify-content-between { justify-content: space-between !important; }
.justify-content-center { justify-content: center !important; }
.justify-content-end { justify-content: flex-end !important; }
.ml-auto { margin-left: auto !important; }
.mr-auto { margin-right: auto !important; }
.mb-auto { margin-bottom: auto !important; }
.mt-auto { margin-top: auto !important; }
.mr-1 { margin-right: 0.25rem !important; }
.mr-2 { margin-right: 0.5rem !important; }
.mr-3 { margin-right: 1rem !important; }
.mr-4 { margin-right: 1.5rem !important; }
.ml-1 { margin-left: 0.25rem !important; }
.ml-2 { margin-left: 0.5rem !important; }
.ml-3 { margin-left: 1rem !important; }
.ml-4 { margin-left: 1.5rem !important; }
.mb-0 { margin-bottom: 0 !important; }
.mb-1 { margin-bottom: 0.25rem !important; }
.mb-2 { margin-bottom: 0.5rem !important; }
.mb-3 { margin-bottom: 1rem !important; }
.mb-4 { margin-bottom: 1.5rem !important; }
.mt-0 { margin-top: 0 !important; }
.mt-1 { margin-top: 0.25rem !important; }
.mt-2 { margin-top: 0.5rem !important; }
.mt-3 { margin-top: 1rem !important; }
.mt-4 { margin-top: 1.5rem !important; }
.p-0 { padding: 0 !important; }
.p-2 { padding: 0.5rem !important; }
.p-3 { padding: 1rem !important; }
.p-4 { padding: 1.5rem !important; }
.pl-4 { padding-left: 1.5rem !important; }
.pr-2 { padding-right: 0.5rem !important; }
.pt-2 { padding-top: 0.5rem !important; }
.pb-2 { padding-bottom: 0.5rem !important; }
.bg-white { background-color: #fff !important; }
.shadow-sm { box-shadow: 0 1px 3px rgba(0,0,0,0.1) !important; }
.sticky-top { position: sticky; top: 0; z-index: 1020; }
.font-weight-bold { font-weight: 700 !important; }
.font-weight-500 { font-weight: 500 !important; }
.text-primary { color: #1976d2 !important; }
.text-dark { color: #212529 !important; }
.text-danger { color: #dc3545 !important; }
.text-muted { color: #6c757d !important; }
.float-right { float: right !important; }
.float-left { float: left !important; }
.w-100 { width: 100% !important; }
.h5 { font-size: 1.25rem; }
/* Navbar Bootstrap 4 compat */
.navbar-expand-lg .navbar-collapse { display: flex !important; flex-basis: auto; }
.navbar-expand-lg .navbar-toggler { display: none; }
.navbar-expand-lg .navbar-nav { flex-direction: row; }
.navbar-nav { display: flex; flex-direction: column; padding-left: 0; margin-bottom: 0; list-style: none; }
.navbar-light .navbar-brand { color: #333; }
.navbar-light .nav-link { color: #555; }
/* Dropdown compat */
.dropdown-divider { height: 0; margin: 0.5rem 0; overflow: hidden; border-top: 1px solid #e9ecef; }
.dropdown-menu-right { right: 0; left: auto; }
/* Form control sm */
.form-control-sm { height: calc(1.5em + 0.5rem + 2px); padding: 0.25rem 0.5rem; font-size: 0.875rem; }

/* ============================================================
   Main Layout (Bootstrap 3 grid-based)
   ============================================================ */
.main-container {
    padding-left: 0;
    padding-right: 0;
}

.main-row {
    min-height: calc(100vh - 54px);
}

/* Page content area */
.page-container {
    background-color: #f9fafb;
    min-height: calc(100vh - 54px);
    padding-top: 1rem;
}

body.dark-mode .page-container {
    background-color: #0f172a;
}

/* Page title */
.page-title h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #0f172a;
    margin: 0 0 1.5rem 0;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid #e2e8f0;
}

body.dark-mode .page-title h1 {
    color: #f1f5f9;
    border-bottom-color: #334155;
}

.menubar {
    margin-top: 0;
    margin-bottom: 1rem;
}