/* ===================================
   LMS Platform - Main Stylesheet
   Modern Ukrainian Design System
   =================================== */

/* CSS Variables */
:root {
    /* Colors - Deep teal & warm accents */
    --color-primary: #0D9488;
    --color-primary-dark: #0F766E;
    --color-primary-light: #14B8A6;
    --color-primary-bg: #F0FDFA;
    
    --color-secondary: #F59E0B;
    --color-secondary-dark: #D97706;
    
    --color-accent: #8B5CF6;
    --color-accent-light: #A78BFA;
    
    /* Neutrals */
    --color-text: #1E293B;
    --color-text-light: #64748B;
    --color-text-muted: #94A3B8;
    
    --color-bg: #FFFFFF;
    --color-bg-alt: #F8FAFC;
    --color-bg-dark: #0F172A;
    
    --color-border: #E2E8F0;
    --color-border-light: #F1F5F9;
    
    /* Status */
    --color-success: #10B981;
    --color-success-bg: #ECFDF5;
    --color-warning: #F59E0B;
    --color-warning-bg: #FFFBEB;
    --color-error: #EF4444;
    --color-error-bg: #FEF2F2;
    --color-info: #3B82F6;
    --color-info-bg: #EFF6FF;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition: 200ms ease;
    --transition-slow: 300ms ease;
    
    /* Typography */
    --font-family: 'Manrope', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    
    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    
    /* Layout */
    --container-max: 1280px;
    --header-height: 72px;
}

/* Reset */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: inherit;
    text-decoration: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

input, textarea, select {
    font-family: inherit;
    font-size: inherit;
}

ul, ol {
    list-style: none;
}

/* Container */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--space-4);
}

@media (min-width: 768px) {
    .container {
        padding: 0 var(--space-6);
    }
}

/* ===================================
   Header
   =================================== */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    height: var(--header-height);
}

.header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--header-height);
    gap: var(--space-6);
}

.header__logo {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-weight: 700;
    font-size: var(--font-size-xl);
    color: var(--color-text);
}

.logo-icon {
    font-size: 1.5rem;
}

.header__nav {
    display: none;
    align-items: center;
    gap: var(--space-6);
}

@media (min-width: 768px) {
    .header__nav {
        display: flex;
    }
}

.nav-link {
    font-weight: 500;
    color: var(--color-text-light);
    transition: color var(--transition);
}

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

.header__actions {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

/* Notification Button */
.notification-btn {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    color: var(--color-text-light);
    transition: all var(--transition);
}

.notification-btn:hover {
    background: var(--color-bg-alt);
    color: var(--color-text);
}

.notification-btn .badge {
    position: absolute;
    top: 4px;
    right: 4px;
    min-width: 18px;
    height: 18px;
    padding: 0 5px;
    background: var(--color-error);
    color: white;
    font-size: 11px;
    font-weight: 600;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
}

/* User Dropdown */
.header__user {
    position: relative;
}

.user-btn {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2);
    border-radius: var(--radius-full);
    transition: background var(--transition);
}

.user-btn:hover {
    background: var(--color-bg-alt);
}

.user-avatar {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-full);
    object-fit: cover;
}

.user-avatar--placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-primary);
    color: white;
    font-weight: 600;
    font-size: var(--font-size-sm);
}

.user-name {
    display: none;
    font-weight: 500;
}

@media (min-width: 768px) {
    .user-name {
        display: block;
    }
}

.user-btn i {
    font-size: 12px;
    color: var(--color-text-muted);
}

/* Dropdown */
.dropdown {
    position: relative;
}

.dropdown-menu {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    min-width: 200px;
    background: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--color-border);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition);
    z-index: 50;
}

.dropdown.active .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-item {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    color: var(--color-text);
    font-size: var(--font-size-sm);
    transition: background var(--transition);
}

.dropdown-item:hover {
    background: var(--color-bg-alt);
}

.dropdown-item i {
    width: 16px;
    color: var(--color-text-muted);
}

.dropdown-item--danger {
    color: var(--color-error);
}

.dropdown-item--danger i {
    color: var(--color-error);
}

.dropdown-divider {
    height: 1px;
    background: var(--color-border);
    margin: var(--space-2) 0;
}

/* Mobile Menu Button */
.mobile-menu-btn {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    gap: 5px;
}

.mobile-menu-btn span,
.mobile-menu-btn::before,
.mobile-menu-btn::after {
    content: '';
    display: block;
    width: 20px;
    height: 2px;
    background: var(--color-text);
    border-radius: 2px;
    transition: all var(--transition);
}

@media (min-width: 768px) {
    .mobile-menu-btn {
        display: none;
    }
}

/* Mobile Menu */
.mobile-menu {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: white;
    z-index: 99;
    padding: var(--space-6);
    transform: translateX(100%);
    transition: transform var(--transition-slow);
}

.mobile-menu.active {
    transform: translateX(0);
}

.mobile-menu__nav {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.mobile-menu__nav a {
    font-size: var(--font-size-lg);
    font-weight: 500;
    padding: var(--space-3) 0;
    border-bottom: 1px solid var(--color-border-light);
}

/* ===================================
   Buttons
   =================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-5);
    font-weight: 600;
    font-size: var(--font-size-sm);
    border-radius: var(--radius);
    transition: all var(--transition);
    cursor: pointer;
    border: none;
    white-space: nowrap;
}

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

.btn--primary:hover {
    background: var(--color-primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn--secondary {
    background: var(--color-bg-alt);
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.btn--secondary:hover {
    background: var(--color-border-light);
    border-color: var(--color-border);
}

.btn--ghost {
    background: transparent;
    color: var(--color-text);
}

.btn--ghost:hover {
    background: var(--color-bg-alt);
}

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

.btn--danger:hover {
    background: #DC2626;
}

.btn--lg {
    padding: var(--space-4) var(--space-8);
    font-size: var(--font-size-base);
    border-radius: var(--radius-md);
}

.btn--sm {
    padding: var(--space-2) var(--space-3);
    font-size: var(--font-size-xs);
}

.btn--full {
    width: 100%;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

/* ===================================
   Forms
   =================================== */
.form-group {
    margin-bottom: var(--space-5);
}

.form-label {
    display: block;
    margin-bottom: var(--space-2);
    font-weight: 500;
    font-size: var(--font-size-sm);
    color: var(--color-text);
}

.form-label span {
    color: var(--color-error);
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    background: white;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    font-size: var(--font-size-base);
    color: var(--color-text);
    transition: all var(--transition);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-bg);
}

.form-input::placeholder,
.form-textarea::placeholder {
    color: var(--color-text-muted);
}

.form-textarea {
    min-height: 120px;
    resize: vertical;
}

.form-select {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%2394A3B8'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M19 9l-7 7-7-7'%3E%3C/path%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 20px;
    padding-right: 44px;
}

.form-checkbox {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    cursor: pointer;
}

.form-checkbox input {
    width: 18px;
    height: 18px;
    accent-color: var(--color-primary);
    cursor: pointer;
}

.form-error {
    color: var(--color-error);
    font-size: var(--font-size-sm);
    margin-top: var(--space-2);
}

.form-hint {
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
    margin-top: var(--space-2);
}

/* ===================================
   Cards
   =================================== */
.card {
    background: white;
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    overflow: hidden;
}

.card--hover {
    transition: all var(--transition);
}

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

.card__image {
    aspect-ratio: 16/9;
    overflow: hidden;
}

.card__image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.card--hover:hover .card__image img {
    transform: scale(1.05);
}

.card__body {
    padding: var(--space-5);
}

.card__title {
    font-size: var(--font-size-lg);
    font-weight: 700;
    margin-bottom: var(--space-2);
    color: var(--color-text);
}

.card__desc {
    color: var(--color-text-light);
    font-size: var(--font-size-sm);
    line-height: 1.6;
}

.card__footer {
    padding: var(--space-4) var(--space-5);
    background: var(--color-bg-alt);
    border-top: 1px solid var(--color-border-light);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

/* ===================================
   Flash Messages
   =================================== */
.flash-message {
    padding: var(--space-4) 0;
    font-weight: 500;
}

.flash-message .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.flash-message--success {
    background: var(--color-success-bg);
    color: var(--color-success);
}

.flash-message--error {
    background: var(--color-error-bg);
    color: var(--color-error);
}

.flash-message--warning {
    background: var(--color-warning-bg);
    color: var(--color-warning);
}

.flash-message--info {
    background: var(--color-info-bg);
    color: var(--color-info);
}

.flash-close {
    font-size: var(--font-size-xl);
    opacity: 0.7;
    cursor: pointer;
    transition: opacity var(--transition);
}

.flash-close:hover {
    opacity: 1;
}

/* ===================================
   Alerts
   =================================== */
.alert {
    padding: var(--space-4);
    border-radius: var(--radius);
    margin-bottom: var(--space-4);
}

.alert--error {
    background: var(--color-error-bg);
    border: 1px solid #FECACA;
    color: var(--color-error);
}

.alert--success {
    background: var(--color-success-bg);
    border: 1px solid #A7F3D0;
    color: var(--color-success);
}

.alert ul {
    margin-top: var(--space-2);
    padding-left: var(--space-5);
}

.alert li {
    list-style: disc;
}

/* ===================================
   Main Content
   =================================== */
.main {
    flex: 1;
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--color-bg-dark);
    color: white;
    padding: var(--space-12) 0 var(--space-6);
    margin-top: auto;
}

.footer__inner {
    display: grid;
    gap: var(--space-8);
}

@media (min-width: 768px) {
    .footer__inner {
        grid-template-columns: 1fr 1fr;
    }
}

.footer__logo {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--font-size-xl);
    font-weight: 700;
    margin-bottom: var(--space-4);
}

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

.footer__links h4 {
    font-size: var(--font-size-sm);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-4);
    color: var(--color-text-muted);
}

.footer__links ul {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.footer__links a {
    color: #CBD5E1;
    transition: color var(--transition);
}

.footer__links a:hover {
    color: white;
}

.footer__bottom {
    margin-top: var(--space-8);
    padding-top: var(--space-6);
    border-top: 1px solid #334155;
    text-align: center;
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    background: linear-gradient(135deg, var(--color-bg-dark) 0%, #1E293B 100%);
    color: white;
    padding: var(--space-16) 0;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    opacity: 0.5;
}

.hero__inner {
    position: relative;
    z-index: 1;
    max-width: 800px;
}

.hero__badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    margin-bottom: var(--space-6);
}

.hero__title {
    font-size: clamp(2rem, 5vw, var(--font-size-5xl));
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--space-6);
}

.hero__title span {
    background: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero__desc {
    font-size: var(--font-size-lg);
    color: #94A3B8;
    margin-bottom: var(--space-8);
    max-width: 600px;
}

.hero__actions {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-4);
}

/* ===================================
   Page Header
   =================================== */
.page-header {
    background: var(--color-bg-alt);
    padding: var(--space-8) 0;
    border-bottom: 1px solid var(--color-border);
}

.page-header__inner {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

@media (min-width: 768px) {
    .page-header__inner {
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
    }
}

.page-header__title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
}

.breadcrumb {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

.breadcrumb a {
    color: var(--color-text-light);
    transition: color var(--transition);
}

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

.breadcrumb span {
    color: var(--color-text);
}

/* ===================================
   Grid
   =================================== */
.grid {
    display: grid;
    gap: var(--space-6);
}

.grid--2 { grid-template-columns: repeat(1, 1fr); }
.grid--3 { grid-template-columns: repeat(1, 1fr); }
.grid--4 { grid-template-columns: repeat(2, 1fr); }

@media (min-width: 640px) {
    .grid--2 { grid-template-columns: repeat(2, 1fr); }
    .grid--3 { grid-template-columns: repeat(2, 1fr); }
    .grid--4 { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
    .grid--3 { grid-template-columns: repeat(3, 1fr); }
    .grid--4 { grid-template-columns: repeat(4, 1fr); }
}

/* ===================================
   Course Card
   =================================== */
.course-card {
    display: flex;
    flex-direction: column;
    height: 100%;
}

.course-card__image {
    position: relative;
}

.course-card__badge {
    position: absolute;
    top: var(--space-3);
    left: var(--space-3);
    padding: var(--space-1) var(--space-3);
    background: var(--color-secondary);
    color: white;
    font-size: var(--font-size-xs);
    font-weight: 600;
    border-radius: var(--radius-full);
}

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

.course-card__meta {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    margin-bottom: var(--space-3);
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

.course-card__meta i {
    margin-right: var(--space-1);
    color: var(--color-primary);
}

.course-card__price {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--color-primary);
}

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

/* ===================================
   Progress Bar
   =================================== */
.progress {
    height: 8px;
    background: var(--color-border);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress__bar {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    border-radius: var(--radius-full);
    transition: width var(--transition-slow);
}

.progress--lg {
    height: 12px;
}

/* ===================================
   Section
   =================================== */
.section {
    padding: var(--space-12) 0;
}

.section__header {
    text-align: center;
    margin-bottom: var(--space-10);
}

.section__title {
    font-size: var(--font-size-3xl);
    font-weight: 800;
    margin-bottom: var(--space-4);
}

.section__desc {
    color: var(--color-text-light);
    max-width: 600px;
    margin: 0 auto;
}

/* ===================================
   Utilities
   =================================== */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-primary { color: var(--color-primary); }
.text-success { color: var(--color-success); }
.text-warning { color: var(--color-warning); }
.text-danger { color: var(--color-error); }
.text-muted { color: var(--color-text-muted); }

.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }

.hidden { display: none !important; }

@media (max-width: 767px) {
    .hidden-mobile { display: none !important; }
}

@media (min-width: 768px) {
    .hidden-desktop { display: none !important; }
}

/* ===================================
   Pagination
   =================================== */
.pagination {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    margin-top: var(--space-8);
}

.pagination__item {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 40px;
    height: 40px;
    padding: 0 var(--space-3);
    border-radius: var(--radius);
    font-weight: 500;
    color: var(--color-text-light);
    transition: all var(--transition);
}

.pagination__item:hover {
    background: var(--color-bg-alt);
    color: var(--color-text);
}

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

.pagination__item.disabled {
    opacity: 0.5;
    pointer-events: none;
}

/* ===================================
   Empty State
   =================================== */
.empty-state {
    text-align: center;
    padding: var(--space-12) var(--space-6);
}

.empty-state__icon {
    font-size: 4rem;
    margin-bottom: var(--space-4);
    opacity: 0.5;
}

.empty-state__title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--space-2);
}

.empty-state__desc {
    color: var(--color-text-muted);
    margin-bottom: var(--space-6);
}

/* ===================================
   Badge
   =================================== */
.badge {
    display: inline-flex;
    align-items: center;
    padding: var(--space-1) var(--space-3);
    font-size: var(--font-size-xs);
    font-weight: 600;
    border-radius: var(--radius-full);
}

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

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

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

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

/* ===================================
   Tabs
   =================================== */
.tabs {
    display: flex;
    gap: var(--space-1);
    padding: var(--space-1);
    background: var(--color-bg-alt);
    border-radius: var(--radius);
    margin-bottom: var(--space-6);
}

.tab {
    flex: 1;
    padding: var(--space-3) var(--space-4);
    text-align: center;
    font-weight: 500;
    color: var(--color-text-light);
    border-radius: var(--radius-sm);
    transition: all var(--transition);
    cursor: pointer;
}

.tab:hover {
    color: var(--color-text);
}

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

/* ===================================
   Table
   =================================== */
.table-wrapper {
    overflow-x: auto;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
}

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

.table th,
.table td {
    padding: var(--space-4);
    text-align: left;
    border-bottom: 1px solid var(--color-border);
}

.table th {
    background: var(--color-bg-alt);
    font-weight: 600;
    font-size: var(--font-size-sm);
    color: var(--color-text-light);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

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

.table tr:hover td {
    background: var(--color-bg-alt);
}

/* ===================================
   Modal
   =================================== */
.modal {
    position: fixed;
    inset: 0;
    z-index: 200;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-4);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition);
}

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

.modal__backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
}

.modal__content {
    position: relative;
    background: white;
    border-radius: var(--radius-lg);
    max-width: 500px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    transform: scale(0.95);
    transition: transform var(--transition);
}

.modal.active .modal__content {
    transform: scale(1);
}

.modal__header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-5);
    border-bottom: 1px solid var(--color-border);
}

.modal__title {
    font-size: var(--font-size-lg);
    font-weight: 700;
}

.modal__close {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius);
    color: var(--color-text-muted);
    transition: all var(--transition);
}

.modal__close:hover {
    background: var(--color-bg-alt);
    color: var(--color-text);
}

.modal__body {
    padding: var(--space-5);
}

.modal__footer {
    display: flex;
    justify-content: flex-end;
    gap: var(--space-3);
    padding: var(--space-5);
    border-top: 1px solid var(--color-border);
}

/* ===================================
   Loader
   =================================== */
.loader {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--color-border);
    border-radius: 50%;
    border-top-color: var(--color-primary);
    animation: spin 0.8s linear infinite;
}

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

.loader--lg {
    width: 40px;
    height: 40px;
    border-width: 3px;
}

/* ===================================
   Video Player
   =================================== */
.video-player {
    position: relative;
    aspect-ratio: 16/9;
    background: #000;
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.video-player video {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.video-player__watermark {
    position: absolute;
    bottom: 20px;
    right: 20px;
    color: rgba(255, 255, 255, 0.3);
    font-size: var(--font-size-sm);
    pointer-events: none;
    user-select: none;
}

.video-player__overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.3);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition);
}

.video-player:hover .video-player__overlay {
    opacity: 1;
}

.video-player__play {
    width: 80px;
    height: 80px;
    background: rgba(255, 255, 255, 0.9);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: var(--color-primary);
    transition: transform var(--transition);
}

.video-player__play:hover {
    transform: scale(1.1);
}

/* ===================================
   Lesson Sidebar
   =================================== */
.lesson-sidebar {
    background: white;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.lesson-sidebar__header {
    padding: var(--space-4);
    background: var(--color-bg-alt);
    border-bottom: 1px solid var(--color-border);
}

.lesson-sidebar__title {
    font-weight: 600;
    font-size: var(--font-size-sm);
    color: var(--color-text-light);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.lesson-item {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-4);
    border-bottom: 1px solid var(--color-border-light);
    transition: background var(--transition);
}

.lesson-item:last-child {
    border-bottom: none;
}

.lesson-item:hover {
    background: var(--color-bg-alt);
}

.lesson-item.active {
    background: var(--color-primary-bg);
    border-left: 3px solid var(--color-primary);
}

.lesson-item.completed {
    opacity: 0.8;
}

.lesson-item.locked {
    opacity: 0.5;
    cursor: not-allowed;
}

.lesson-item__icon {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-sm);
    flex-shrink: 0;
}

.lesson-item.completed .lesson-item__icon {
    background: var(--color-success);
    color: white;
}

.lesson-item.active .lesson-item__icon {
    background: var(--color-primary);
    color: white;
}

.lesson-item.locked .lesson-item__icon {
    background: var(--color-border);
    color: var(--color-text-muted);
}

.lesson-item__title {
    flex: 1;
    font-size: var(--font-size-sm);
    font-weight: 500;
}

.lesson-item__duration {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
}