/*
|--------------------------------------------------------------------------
| XLTips Design System v2.0
|--------------------------------------------------------------------------
| Product : XLTips — LMS, Training & Automation Services
| Purpose : Master Global Design System & Component Library
| Stack   : Bootstrap 5 compatible, Vanilla CSS
| Target  : 375px -> 1920px Responsive
|--------------------------------------------------------------------------
*/

/* ==========================================================================
   TABLE OF CONTENTS
   ==========================================================================
   01. DESIGN TOKENS & CSS VARIABLES
   02. RESET & BASE ELEMENTS
   03. TYPOGRAPHY & TEXT UTILITIES
   04. BUTTONS & INTERACTIVE LINKS
   05. FORMS, INPUTS & VALIDATION
   06. CARDS & CONTAINERS
   07. BADGES, TAGS & STATUS PILLS
   08. ALERTS & NOTIFICATIONS
   09. TABLES & DATA LISTS
   10. PAGINATION
   11. MODALS & DIALOGS
   12. DROPDOWNS & ACTION MENUS
   13. TABS, PILLS & ACCORDIONS
   14. SITE HEADER, NAVBAR & NAVIGATION
   15. SITE FOOTER
   16. HERO SECTIONS
   17. LMS & COURSE COMPONENTS
   18. LESSON & VIDEO PLAYER INTERFACE
   19. LIVE CLASS COMPONENTS
   20. WEBINAR COMPONENTS
   21. CERTIFICATE & VERIFICATION
   22. DASHBOARD & STAT METRIC CARDS
   23. ADMIN PANEL & SIDEBAR
   24. EMPTY STATES, SKELETON LOADERS & FEEDBACK
   25. RESPONSIVE UTILITIES & BREAKPOINTS
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&display=swap');

/* ==========================================================================
   01. DESIGN TOKENS & CSS VARIABLES
   ========================================================================== */

:root {
    /* Brand Colors (Spec section 5) */
    --primary: #2E7D32;
    --primary-dark: #1B5E20;
    --primary-light: #66BB6A;
    --primary-subtle: #E8F5E9;
    --accent: #81C784;

    /* Bootstrap 5 Theme Overrides to Match Website Green Palette */
    --bs-primary: #2E7D32;
    --bs-primary-rgb: 46, 125, 50;
    --bs-primary-text-emphasis: #1B5E20;
    --bs-primary-bg-subtle: #E8F5E9;
    --bs-primary-border-subtle: #C8E6C9;
    --bs-link-color: #2E7D32;
    --bs-link-hover-color: #1B5E20;

    /* Backgrounds & Surfaces */
    --bg: #F8FAFC;
    --surface: #FFFFFF;
    --surface-subtle: #F1F5F9;
    --surface-hover: #F8FAFC;

    /* Typography Colors */
    --heading: #212121;
    --text: #424242;
    --text-muted: #757575;
    --text-light: #9E9E9E;
    --white: #FFFFFF;

    /* Borders & Dividers */
    --border: #E5E7EB;
    --border-light: #F3F4F6;
    --border-dark: #D1D5DB;

    /* Semantic / Feedback */
    --success: #43A047;
    --success-subtle: #E8F5E9;
    --warning: #FB8C00;
    --warning-subtle: #FFF3E0;
    --danger: #E53935;
    --danger-subtle: #FFEBEE;
    --info: #0288D1;
    --info-subtle: #E1F5FE;

    /* Typography Configuration */
    --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    --font-mono: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;

    /* Shadows (Clean, Subtle, Corporate) */
    --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.04), 0 1px 2px rgba(0, 0, 0, 0.02);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06), 0 2px 4px rgba(0, 0, 0, 0.03);
    --shadow-lg: 0 12px 24px -4px rgba(0, 0, 0, 0.08), 0 4px 8px -2px rgba(0, 0, 0, 0.04);
    --shadow-xl: 0 20px 32px -6px rgba(0, 0, 0, 0.1), 0 8px 16px -4px rgba(0, 0, 0, 0.05);

    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-xl: 20px;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 0.15s ease-in-out;
    --transition-base: 0.25s ease-in-out;
    --transition-smooth: 0.35s cubic-bezier(0.4, 0, 0.2, 1);

    /* Layout & Sizing */
    --header-height: 80px;
    --sidebar-width: 260px;
}

/* ==========================================================================
   02. RESET & BASE ELEMENTS
   ========================================================================== */

*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-sans);
    font-size: 0.9375rem;
    /* 15px */
    font-weight: 400;
    line-height: 1.6;
    color: var(--text);
    background-color: var(--bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img,
svg,
picture {
    max-width: 100%;
    height: auto;
    vertical-align: middle;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* ==========================================================================
   03. TYPOGRAPHY & TEXT UTILITIES
   ========================================================================== */

h1,
h2,
h3,
h4,
h5,
h6,
.h1,
.h2,
.h3,
.h4,
.h5,
.h6 {
    font-family: var(--font-sans);
    font-weight: 700;
    color: var(--heading);
    line-height: 1.25;
    margin-top: 0;
    margin-bottom: 0.75rem;
    letter-spacing: -0.02em;
}

h1,
.h1 {
    font-size: 2.25rem;
}

/* 36px */
h2,
.h2 {
    font-size: 1.875rem;
}

/* 30px */
h3,
.h3 {
    font-size: 1.5rem;
}

/* 24px */
h4,
.h4 {
    font-size: 1.25rem;
}

/* 20px */
h5,
.h5 {
    font-size: 1.125rem;
}

/* 18px */
h6,
.h6 {
    font-size: 1rem;
    font-weight: 600;
}

/* 16px */

@media (min-width: 992px) {

    h1,
    .h1 {
        font-size: 2.75rem;
    }

    /* 44px */
    h2,
    .h2 {
        font-size: 2.125rem;
    }

    /* 34px */
    h3,
    .h3 {
        font-size: 1.625rem;
    }

    /* 26px */
}

p {
    margin-top: 0;
    margin-bottom: 1rem;
}

.lead {
    font-size: 1.125rem;
    font-weight: 400;
    line-height: 1.6;
    color: var(--text-muted);
}

.text-heading {
    color: var(--heading) !important;
}

.text-body {
    color: var(--text) !important;
}

.text-muted {
    color: var(--text-muted) !important;
}

.text-primary,
.text-primary-custom {
    color: var(--primary) !important;
}

.bg-primary {
    background-color: var(--primary) !important;
}

.bg-primary-subtle {
    background-color: var(--primary-subtle) !important;
    color: var(--primary-dark) !important;
}

.border-primary {
    border-color: var(--primary) !important;
}

.form-check-input:checked {
    background-color: var(--primary) !important;
    border-color: var(--primary) !important;
}

.form-check-input:focus {
    border-color: var(--primary-light) !important;
    box-shadow: 0 0 0 0.25rem rgba(46, 125, 50, 0.2) !important;
}

.text-success-custom {
    color: var(--success) !important;
}

.text-warning-custom {
    color: var(--warning) !important;
}

.text-danger-custom {
    color: var(--danger) !important;
}

.text-info-custom {
    color: var(--info) !important;
}

.section-label {
    display: inline-block;
    font-size: 0.8125rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--primary);
    background-color: var(--primary-subtle);
    padding: 0.35rem 0.85rem;
    border-radius: var(--radius-full);
    margin-bottom: 0.75rem;
}

.section-title {
    font-size: 1.875rem;
    font-weight: 800;
    color: var(--heading);
    margin-bottom: 0.75rem;
}

@media (min-width: 992px) {
    .section-title {
        font-size: 2.25rem;
    }
}

.section-subtitle {
    font-size: 1.0625rem;
    color: var(--text-muted);
    max-width: 680px;
    margin-bottom: 2.5rem;
}

/* ==========================================================================
   04. BUTTONS & INTERACTIVE LINKS
   ========================================================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-family: var(--font-sans);
    font-size: 0.9375rem;
    font-weight: 600;
    line-height: 1.4;
    padding: 0.625rem 1.25rem;
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    cursor: pointer;
    text-decoration: none;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.btn:disabled,
.btn.disabled {
    opacity: 0.65;
    cursor: not-allowed;
    pointer-events: none;
}

/* Primary Button */
.btn-primary {
    background-color: var(--primary);
    border-color: var(--primary);
    color: var(--white) !important;
}

.btn-primary:hover,
.btn-primary:active {
    background-color: var(--primary-dark) !important;
    border-color: var(--primary-dark) !important;
    color: var(--white) !important;
    box-shadow: 0 4px 10px rgba(46, 125, 50, 0.25);
}

/* Secondary Button */
.btn-secondary {
    background-color: var(--surface-subtle);
    border-color: var(--border);
    color: var(--heading) !important;
}

.btn-secondary:hover,
.btn-secondary:active {
    background-color: #E2E8F0 !important;
    border-color: #CBD5E1 !important;
    color: var(--heading) !important;
}

/* Outline Buttons */
.btn-outline-primary {
    background-color: transparent;
    border-color: var(--primary);
    color: var(--primary) !important;
}

.btn-outline-primary:hover,
.btn-outline-primary:active {
    background-color: var(--primary) !important;
    border-color: var(--primary) !important;
    color: var(--white) !important;
}

.btn-outline-secondary {
    background-color: transparent;
    border-color: var(--border);
    color: var(--text) !important;
}

.btn-outline-secondary:hover {
    background-color: var(--surface-subtle);
    border-color: var(--border-dark);
    color: var(--heading) !important;
}

/* Status / Action Buttons */
.btn-success {
    background-color: var(--success);
    border-color: var(--success);
    color: var(--white) !important;
}

.btn-success:hover {
    background-color: #388E3C !important;
    border-color: #388E3C !important;
}

.btn-danger {
    background-color: var(--danger);
    border-color: var(--danger);
    color: var(--white) !important;
}

.btn-danger:hover {
    background-color: #C62828 !important;
    border-color: #C62828 !important;
}

.btn-warning {
    background-color: var(--warning);
    border-color: var(--warning);
    color: var(--white) !important;
}

.btn-warning:hover {
    background-color: #EF6C00 !important;
    border-color: #EF6C00 !important;
}

.btn-info {
    background-color: var(--info);
    border-color: var(--info);
    color: var(--white) !important;
}

.btn-info:hover {
    background-color: #0277BD !important;
    border-color: #0277BD !important;
}

/* Button Sizing */
.btn-sm {
    font-size: 0.8125rem;
    padding: 0.4rem 0.875rem;
    border-radius: var(--radius-sm);
}

.btn-lg {
    font-size: 1rem;
    font-weight: 700;
    padding: 0.8125rem 1.75rem;
    border-radius: var(--radius-lg);
}

.btn-icon {
    width: 38px;
    height: 38px;
    padding: 0;
    border-radius: var(--radius-md);
}

/* ==========================================================================
   05. FORMS, INPUTS & VALIDATION
   ========================================================================== */

.form-label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--heading);
    margin-bottom: 0.4rem;
    display: inline-block;
}

.form-label .required {
    color: var(--danger);
    margin-left: 2px;
}

.form-control,
.form-select {
    display: block;
    width: 100%;
    font-family: var(--font-sans);
    font-size: 0.9375rem;
    font-weight: 400;
    line-height: 1.5;
    color: var(--heading);
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 0.625rem 0.875rem;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-control:focus,
.form-select:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(46, 125, 50, 0.15);
    outline: none;
}

.form-control::placeholder {
    color: var(--text-light);
}

.form-control:disabled,
.form-control[readonly],
.form-select:disabled {
    background-color: var(--surface-subtle);
    cursor: not-allowed;
    opacity: 0.8;
}

textarea.form-control {
    min-height: 110px;
    resize: vertical;
}

.form-text {
    font-size: 0.8125rem;
    color: var(--text-muted);
    margin-top: 0.35rem;
}

/* Form Check / Radio */
.form-check {
    display: flex;
    align-items: center;
    gap: 0.625rem;
    margin-bottom: 0.5rem;
    padding-left: 0;
}

.form-check-input {
    width: 1.125rem;
    height: 1.125rem;
    margin-top: 0;
    border: 1px solid var(--border-dark);
    border-radius: 4px;
    cursor: pointer;
    background-color: var(--surface);
    transition: all var(--transition-fast);
}

.form-check-input[type="radio"] {
    border-radius: 50%;
}

.form-check-input:checked {
    background-color: var(--primary);
    border-color: var(--primary);
}

.form-check-input:focus {
    box-shadow: 0 0 0 3px rgba(46, 125, 50, 0.15);
    border-color: var(--primary);
}

.form-check-label {
    font-size: 0.875rem;
    color: var(--text);
    cursor: pointer;
    user-select: none;
}

/* Validation States */
.form-control.is-invalid,
.form-select.is-invalid {
    border-color: var(--danger);
    padding-right: calc(1.5em + 0.75rem);
}

.form-control.is-invalid:focus,
.form-select.is-invalid:focus {
    box-shadow: 0 0 0 3px rgba(229, 57, 53, 0.15);
}

.invalid-feedback {
    display: block;
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--danger);
    margin-top: 0.35rem;
}

.form-control.is-valid,
.form-select.is-valid {
    border-color: var(--success);
}

.valid-feedback {
    display: block;
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--success);
    margin-top: 0.35rem;
}

/* Input Groups */
.input-group {
    display: flex;
    align-items: stretch;
    width: 100%;
}

.input-group-text {
    display: flex;
    align-items: center;
    padding: 0.625rem 0.875rem;
    font-size: 0.9375rem;
    color: var(--text-muted);
    background-color: var(--surface-subtle);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
}

.input-group>.form-control:not(:last-child),
.input-group>.input-group-text:not(:last-child) {
    border-top-right-radius: 0;
    border-bottom-right-radius: 0;
}

.input-group>.form-control:not(:first-child),
.input-group>.input-group-text:not(:first-child) {
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
    margin-left: -1px;
}

/* ==========================================================================
   06. CARDS & CONTAINERS
   ========================================================================== */

.card {
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xs);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast);
    overflow: hidden;
    position: relative;
}

.card-hover:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
    border-color: #D1D5DB;
}

.card-header {
    background-color: var(--surface);
    border-bottom: 1px solid var(--border-light);
    padding: 1.25rem 1.5rem;
    font-weight: 700;
    color: var(--heading);
}

.card-body {
    padding: 1.5rem;
}

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

.card-title {
    font-size: 1.1875rem;
    font-weight: 700;
    color: var(--heading);
    margin-bottom: 0.5rem;
}

.card-subtitle {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
}

/* Stat Card */
.stat-card {
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    background: var(--surface);
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 1.25rem;
}

.stat-icon {
    width: 52px;
    height: 52px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    flex-shrink: 0;
}

.stat-icon.primary {
    background-color: var(--primary-subtle);
    color: var(--primary);
}

.stat-icon.success {
    background-color: var(--success-subtle);
    color: var(--success);
}

.stat-icon.warning {
    background-color: var(--warning-subtle);
    color: var(--warning);
}

.stat-icon.info {
    background-color: var(--info-subtle);
    color: var(--info);
}

.stat-icon.danger {
    background-color: var(--danger-subtle);
    color: var(--danger);
}

.stat-value {
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--heading);
    line-height: 1.2;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-muted);
    font-weight: 500;
}

/* ==========================================================================
   07. BADGES, TAGS & STATUS PILLS
   ========================================================================== */

.badge {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    font-size: 0.75rem;
    font-weight: 700;
    line-height: 1;
    padding: 0.35rem 0.65rem;
    border-radius: var(--radius-sm);
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.badge-pill {
    border-radius: var(--radius-full);
}

.badge-primary {
    background-color: var(--primary-subtle);
    color: var(--primary);
}

.badge-success {
    background-color: var(--success-subtle);
    color: var(--success);
}

.badge-warning {
    background-color: var(--warning-subtle);
    color: var(--warning);
}

.badge-danger {
    background-color: var(--danger-subtle);
    color: var(--danger);
}

.badge-info {
    background-color: var(--info-subtle);
    color: var(--info);
}

.badge-neutral {
    background-color: var(--surface-subtle);
    color: var(--text-muted);
}

/* Status Indicator Dot */
.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    display: inline-block;
}

.status-dot.active,
.status-dot.success {
    background-color: var(--success);
}

.status-dot.pending,
.status-dot.warning {
    background-color: var(--warning);
}

.status-dot.danger,
.status-dot.inactive {
    background-color: var(--danger);
}

.status-dot.info {
    background-color: var(--info);
}

/* ==========================================================================
   08. ALERTS & NOTIFICATIONS
   ========================================================================== */

.alert {
    padding: 1rem 1.25rem;
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    margin-bottom: 1.25rem;
    display: flex;
    align-items: flex-start;
    gap: 0.875rem;
    font-size: 0.9375rem;
    line-height: 1.5;
}

.alert-icon {
    font-size: 1.25rem;
    line-height: 1;
    flex-shrink: 0;
    margin-top: 2px;
}

.alert-primary {
    background-color: var(--primary-subtle);
    border-color: #C8E6C9;
    color: var(--primary-dark);
}

.alert-success {
    background-color: var(--success-subtle);
    border-color: #C8E6C9;
    color: #1B5E20;
}

.alert-warning {
    background-color: var(--warning-subtle);
    border-color: #FFE0B2;
    color: #E65100;
}

.alert-danger {
    background-color: var(--danger-subtle);
    border-color: #FFCDD2;
    color: #B71C1C;
}

.alert-info {
    background-color: var(--info-subtle);
    border-color: #B3E5FC;
    color: #01579B;
}

/* ==========================================================================
   09. TABLES & DATA LISTS
   ========================================================================== */

.table-responsive {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    background: var(--surface);
}

.table {
    width: 100%;
    margin-bottom: 0;
    color: var(--text);
    vertical-align: middle;
    border-collapse: collapse;
}

.table th {
    font-size: 0.8125rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    background-color: var(--surface-subtle);
    padding: 0.875rem 1.25rem;
    border-bottom: 1px solid var(--border);
    white-space: nowrap;
}

.table td {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border-light);
    font-size: 0.9375rem;
}

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

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

.table-striped tbody tr:nth-of-type(odd) {
    background-color: #FAFBFD;
}

/* ==========================================================================
   10. PAGINATION
   ========================================================================== */

.pagination {
    display: flex;
    list-style: none;
    padding: 0;
    margin: 1.5rem 0 0 0;
    gap: 0.35rem;
    align-items: center;
    justify-content: center;
}

.page-item .page-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 36px;
    height: 36px;
    padding: 0 0.75rem;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text);
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    text-decoration: none;
}

.page-item .page-link:hover {
    background-color: var(--surface-subtle);
    border-color: var(--border-dark);
    color: var(--heading);
}

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

.page-item.disabled .page-link {
    opacity: 0.5;
    cursor: not-allowed;
    background-color: var(--surface-subtle);
}

/* ==========================================================================
   11. MODALS & DIALOGS
   ========================================================================== */

.modal-content {
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
}

.modal-header {
    border-bottom: 1px solid var(--border-light);
    padding: 1.25rem 1.5rem;
    align-items: center;
}

.modal-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--heading);
}

.modal-body {
    padding: 1.5rem;
}

.modal-footer {
    border-top: 1px solid var(--border-light);
    padding: 1rem 1.5rem;
    gap: 0.75rem;
}

/* ==========================================================================
   12. DROPDOWNS & ACTION MENUS
   ========================================================================== */

.dropdown-menu {
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    padding: 0.5rem;
    min-width: 190px;
}

.dropdown-item {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text);
    padding: 0.5rem 0.875rem;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    gap: 0.625rem;
    transition: all var(--transition-fast);
}

.dropdown-item:hover,
.dropdown-item:focus {
    background-color: var(--surface-subtle);
    color: var(--primary);
}

.dropdown-divider {
    border-top: 1px solid var(--border-light);
    margin: 0.4rem 0;
}

/* ==========================================================================
   13. TABS, PILLS & ACCORDIONS
   ========================================================================== */

.nav-tabs-custom {
    display: flex;
    gap: 1.5rem;
    border-bottom: 2px solid var(--border);
    margin-bottom: 1.5rem;
}

.nav-tabs-custom .nav-link {
    font-size: 0.9375rem;
    font-weight: 600;
    color: var(--text-muted);
    padding: 0.75rem 0;
    border: none;
    background: transparent;
    border-bottom: 2px solid transparent;
    margin-bottom: -2px;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.nav-tabs-custom .nav-link:hover {
    color: var(--primary);
}

.nav-tabs-custom .nav-link.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}

/* Accordion */
.accordion-item {
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md) !important;
    margin-bottom: 0.75rem;
    overflow: hidden;
}

.accordion-button {
    font-weight: 700;
    font-size: 1rem;
    color: var(--heading);
    background-color: var(--surface);
    padding: 1.125rem 1.25rem;
    box-shadow: none !important;
}

.accordion-button:not(.collapsed) {
    color: var(--primary);
    background-color: var(--primary-subtle);
}

.accordion-body {
    padding: 1.25rem;
    font-size: 0.9375rem;
    color: var(--text);
    line-height: 1.6;
    border-top: 1px solid var(--border-light);
}

/* ==========================================================================
   14. SITE HEADER, NAVBAR & NAVIGATION
   ========================================================================== */

.site-header {
    background-color: var(--surface);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1040;
    box-shadow: var(--shadow-xs);
}

.site-header .navbar {
    min-height: var(--header-height);
    padding: 0.75rem 0;
}

.site-logo {
    height: 42px;
    width: auto;
    display: block;
}

.site-header .nav-link {
    font-size: 0.9375rem;
    font-weight: 600;
    color: var(--heading);
    padding: 0.625rem 1rem !important;
    border-radius: var(--radius-md);
    transition: color var(--transition-fast), background-color var(--transition-fast);
}

.site-header .nav-link:hover {
    color: var(--primary);
    background-color: var(--surface-subtle);
}

.site-header .nav-link.active {
    color: var(--primary);
}

.navbar-toggler {
    border: 1px solid var(--border);
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius-md);
}

.navbar-toggler:focus {
    box-shadow: 0 0 0 3px rgba(46, 125, 50, 0.15);
}

/* ==========================================================================
   15. SITE FOOTER
   ========================================================================== */

.site-footer {
    background-color: #111827;
    color: #9CA3AF;
    padding-top: 4.5rem;
    padding-bottom: 2rem;
    margin-top: 5rem;
}

.site-footer h5,
.site-footer .footer-title {
    color: var(--white);
    font-size: 1.0625rem;
    font-weight: 700;
    margin-bottom: 1.25rem;
}

.site-footer a {
    color: #9CA3AF;
    transition: color var(--transition-fast);
}

.site-footer a:hover {
    color: var(--white);
}

.footer-links {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-links li {
    margin-bottom: 0.625rem;
}

.footer-bottom {
    border-top: 1px solid #1F2937;
    padding-top: 2rem;
    margin-top: 3.5rem;
    font-size: 0.875rem;
}

/* ==========================================================================
   16. HERO SECTIONS
   ========================================================================== */

.hero-section {
    padding: 4.5rem 0;
    background: linear-gradient(180deg, var(--surface) 0%, var(--bg) 100%);
    border-bottom: 1px solid var(--border);
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 800;
    line-height: 1.15;
    color: var(--heading);
    margin-bottom: 1.25rem;
}

@media (min-width: 992px) {
    .hero-title {
        font-size: 3.25rem;
    }
}

.hero-title .text-highlight {
    color: var(--primary);
    position: relative;
}

.hero-subtitle {
    font-size: 1.1875rem;
    line-height: 1.6;
    color: var(--text-muted);
    margin-bottom: 2rem;
}

.hero-stats-bar {
    margin-top: 3.5rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
}

/* ==========================================================================
   17. LMS & COURSE COMPONENTS
   ========================================================================== */

.course-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    height: 100%;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.course-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.course-card-thumb {
    position: relative;
    aspect-ratio: 16 / 9;
    background-color: #E2E8F0;
    overflow: hidden;
}

.course-card-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-smooth);
}

.course-card:hover .course-card-thumb img {
    transform: scale(1.04);
}

.course-badge-floating {
    position: absolute;
    top: 0.75rem;
    left: 0.75rem;
    z-index: 2;
}

.course-card-body {
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.course-category {
    font-size: 0.8125rem;
    font-weight: 700;
    color: var(--primary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.35rem;
}

.course-title {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--heading);
    line-height: 1.35;
    margin-bottom: 0.5rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.course-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
    font-size: 0.8125rem;
    color: var(--text-muted);
    margin-top: auto;
    padding-top: 1rem;
    border-top: 1px solid var(--border-light);
}

.course-price {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--heading);
}

.course-price.free {
    color: var(--success);
}

/* ==========================================================================
   18. LESSON & VIDEO PLAYER INTERFACE
   ========================================================================== */

.player-container {
    background-color: #000000;
    border-radius: var(--radius-lg);
    overflow: hidden;
    position: relative;
    aspect-ratio: 16 / 9;
}

.curriculum-sidebar {
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    max-height: calc(100vh - 120px);
    overflow-y: auto;
}

.curriculum-module-header {
    background-color: var(--surface-subtle);
    padding: 0.875rem 1.25rem;
    font-weight: 700;
    font-size: 0.9375rem;
    color: var(--heading);
    border-bottom: 1px solid var(--border);
}

.curriculum-lesson-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.875rem 1.25rem;
    border-bottom: 1px solid var(--border-light);
    color: var(--text);
    text-decoration: none;
    font-size: 0.875rem;
    transition: background-color var(--transition-fast);
}

.curriculum-lesson-item:hover {
    background-color: var(--surface-hover);
    color: var(--primary);
}

.curriculum-lesson-item.active {
    background-color: var(--primary-subtle);
    color: var(--primary-dark);
    font-weight: 700;
}

.curriculum-lesson-item.completed .lesson-check {
    color: var(--success);
}

/* ==========================================================================
   19. LIVE CLASS COMPONENTS
   ========================================================================== */

.class-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.class-mode-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.25rem 0.65rem;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
}

.class-mode-online {
    background-color: var(--info-subtle);
    color: var(--info);
}

.class-mode-offline {
    background-color: var(--warning-subtle);
    color: var(--warning);
}

.class-mode-hybrid {
    background-color: var(--primary-subtle);
    color: var(--primary);
}

.seat-progress-bar {
    height: 6px;
    border-radius: var(--radius-full);
    background-color: var(--surface-subtle);
    overflow: hidden;
    margin: 0.5rem 0;
}

.seat-progress-bar .progress-fill {
    height: 100%;
    background-color: var(--primary);
    border-radius: var(--radius-full);
}

/* ==========================================================================
   20. WEBINAR COMPONENTS
   ========================================================================== */

.webinar-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-xs);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.webinar-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.webinar-speaker {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-top: 1rem;
}

.speaker-avatar {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--border);
}

/* ==========================================================================
   21. CERTIFICATE & VERIFICATION
   ========================================================================== */

.certificate-preview-frame {
    border: 8px solid #E2E8F0;
    border-radius: var(--radius-lg);
    background: #FFFFFF;
    box-shadow: var(--shadow-xl);
    padding: 2.5rem;
    position: relative;
    text-align: center;
}

.certificate-seal {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    color: var(--primary);
}

.verification-box {
    background: var(--surface);
    border: 2px dashed var(--border);
    border-radius: var(--radius-lg);
    padding: 2rem;
    text-align: center;
}

/* ==========================================================================
   22. DASHBOARD & STAT METRIC CARDS
   ========================================================================== */

.progress-track {
    background-color: #E2E8F0;
    border-radius: var(--radius-full);
    height: 8px;
    overflow: hidden;
}

.progress-track .progress-bar {
    background-color: var(--primary);
    height: 100%;
    border-radius: var(--radius-full);
    transition: width var(--transition-smooth);
}

.activity-feed {
    list-style: none;
    padding: 0;
    margin: 0;
    position: relative;
}

.activity-item {
    position: relative;
    padding-left: 2rem;
    padding-bottom: 1.5rem;
}

.activity-item::before {
    content: '';
    position: absolute;
    left: 6px;
    top: 6px;
    bottom: -6px;
    width: 2px;
    background-color: var(--border);
}

.activity-item:last-child::before {
    display: none;
}

.activity-item::after {
    content: '';
    position: absolute;
    left: 0;
    top: 6px;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background-color: var(--primary);
    border: 3px solid var(--surface);
}

/* ==========================================================================
   23. ADMIN PANEL & SIDEBAR
   ========================================================================== */

.admin-layout {
    display: flex;
    min-height: 100vh;
}

.admin-sidebar {
    width: var(--sidebar-width);
    background-color: #111827;
    color: #9CA3AF;
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    border-right: 1px solid #1F2937;
    position: sticky;
    top: 0;
    height: 100vh;
    overflow-y: auto;
}

.admin-sidebar .sidebar-brand {
    padding: 1.5rem 1.25rem;
    border-bottom: 1px solid #1F2937;
}

.admin-sidebar .nav-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1.25rem;
    color: #9CA3AF;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    margin: 0.15rem 0.75rem;
    transition: all var(--transition-fast);
}

.admin-sidebar .nav-link:hover,
.admin-sidebar .nav-link.active {
    background-color: #1F2937;
    color: var(--white);
}

.admin-sidebar .nav-link.active {
    background-color: var(--primary);
    color: var(--white);
}

.admin-sidebar .sidebar-heading {
    font-size: 0.6875rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: #6B7280;
    padding: 1rem 1.25rem 0.35rem;
}

.admin-main {
    flex-grow: 1;
    background-color: var(--bg);
    min-width: 0;
    display: flex;
    flex-direction: column;
}

.admin-topbar {
    background-color: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 0.875rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.admin-content {
    padding: 2rem;
    flex-grow: 1;
}

/* ==========================================================================
   24. EMPTY STATES, SKELETON LOADERS & FEEDBACK
   ========================================================================== */

.empty-state {
    text-align: center;
    padding: 4rem 1.5rem;
}

.empty-state-icon {
    font-size: 3rem;
    color: var(--text-light);
    margin-bottom: 1.25rem;
}

.empty-state-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--heading);
    margin-bottom: 0.5rem;
}

.empty-state-text {
    font-size: 0.9375rem;
    color: var(--text-muted);
    max-width: 440px;
    margin: 0 auto 1.5rem;
}

/* Skeleton Loading Animation */
@keyframes skeletonPulse {
    0% {
        background-color: #E2E8F0;
    }

    50% {
        background-color: #F1F5F9;
    }

    100% {
        background-color: #E2E8F0;
    }
}

.skeleton {
    animation: skeletonPulse 1.5s infinite ease-in-out;
    border-radius: var(--radius-sm);
}

.skeleton-text {
    height: 14px;
    margin-bottom: 8px;
    width: 100%;
}

.skeleton-title {
    height: 24px;
    margin-bottom: 12px;
    width: 60%;
}

.skeleton-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
}

.skeleton-card {
    height: 280px;
    border-radius: var(--radius-lg);
}

/* ==========================================================================
   25. RESPONSIVE UTILITIES & BREAKPOINTS (375px -> 1920px)
   ========================================================================== */

@media (max-width: 991.98px) {
    .site-header .navbar-collapse {
        padding: 1rem 0;
        background-color: var(--surface);
    }

    .site-header .nav-item {
        margin-bottom: 0.25rem;
    }

    .admin-layout {
        flex-direction: column;
    }

    .admin-sidebar {
        width: 100%;
        height: auto;
        position: relative;
    }

    .admin-content {
        padding: 1.25rem;
    }
}

@media (max-width: 575.98px) {
    .hero-title {
        font-size: 2rem;
    }

    .section-title {
        font-size: 1.625rem;
    }

    .card-body {
        padding: 1.25rem;
    }

    .stat-card {
        padding: 1rem;
    }
}