/* style.css - Learning Center Stylesheet */
/* Tablet-first responsive design with warm, modern visual style */

/* ===== CSS Custom Properties ===== */
:root {
    /* Colors */
    --color-primary: #2D6A4F;
    --color-primary-light: #40916C;
    --color-primary-dark: #1B4332;
    --color-primary-bg: #D8F3DC;
    --color-secondary: #E76F51;
    --color-secondary-light: #F4A261;
    --color-accent: #2A9D8F;
    --color-accent-light: #95D5B2;

    /* Neutrals */
    --color-bg: #FAFAF9;
    --color-surface: #FFFFFF;
    --color-surface-alt: #F5F5F4;
    --color-border: #E7E5E4;
    --color-border-light: #F0EEED;
    --color-text: #1C1917;
    --color-text-secondary: #57534E;
    --color-text-muted: #A8A29E;

    /* States */
    --color-success: #059669;
    --color-success-bg: #D1FAE5;
    --color-warning: #D97706;
    --color-warning-bg: #FEF3C7;
    --color-error: #DC2626;
    --color-error-bg: #FEE2E2;
    --color-info: #2563EB;
    --color-info-bg: #DBEAFE;

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Noto Sans Thai', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.07), 0 2px 4px -2px rgba(0,0,0,0.05);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -4px rgba(0,0,0,0.04);
    --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.08), 0 8px 10px -6px rgba(0,0,0,0.04);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;

    /* Layout */
    --container-max: 1200px;
    --header-height: 64px;
    --sidebar-width: 260px;
}

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

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

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

img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { color: var(--color-primary-dark); }
ul, ol { list-style: none; }
button { cursor: pointer; font-family: inherit; }
input, select, textarea { font-family: inherit; font-size: inherit; }

/* Screen reader only */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ===== Skip Link ===== */
.skip-link {
    position: absolute;
    top: -100%;
    left: var(--space-md);
    padding: var(--space-sm) var(--space-md);
    background: var(--color-primary);
    color: white;
    border-radius: var(--radius-md);
    z-index: 1000;
    transition: top var(--transition-fast);
}
.skip-link:focus {
    top: var(--space-md);
}

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

/* ===== Header ===== */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    height: var(--header-height);
    backdrop-filter: blur(8px);
    background: rgba(255,255,255,0.95);
}

.header-inner {
    display: flex;
    align-items: center;
    height: var(--header-height);
    gap: var(--space-xl);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    color: var(--color-primary);
    font-weight: 700;
    font-size: 1.125rem;
    flex-shrink: 0;
}

.logo-icon { flex-shrink: 0; }
.brand-logo { display: block; width: 150px; height: 42px; object-fit: contain; }

.logo-text {
    display: none;
}

@media (min-width: 768px) {
    .logo-text { display: inline; }
}

.main-nav {
    display: none;
    gap: var(--space-xs);
    flex: 1;
}

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

.nav-link {
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    color: var(--color-text-secondary);
    font-weight: 500;
    font-size: 0.9375rem;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.nav-link:hover, .nav-link:focus {
    color: var(--color-primary);
    background: var(--color-primary-bg);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    flex-shrink: 0;
}

.lang-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-surface);
    font-weight: 700;
    font-size: 0.8125rem;
    color: var(--color-text);
    transition: all var(--transition-fast);
}

.lang-toggle:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.user-menu {
    position: relative;
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background: var(--color-primary);
    color: white;
    border: none;
    font-weight: 700;
    font-size: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform var(--transition-fast);
}

.user-avatar:hover { transform: scale(1.05); }

.user-dropdown {
    position: absolute;
    top: calc(100% + var(--space-sm));
    right: 0;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    min-width: 180px;
    padding: var(--space-sm);
    display: none;
    z-index: 50;
}

.user-menu:hover .user-dropdown,
.user-menu:focus-within .user-dropdown {
    display: block;
}

.user-dropdown a {
    display: block;
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    color: var(--color-text);
    font-size: 0.9375rem;
}

.user-dropdown a:hover {
    background: var(--color-surface-alt);
}

.user-dropdown .logout-link {
    border-top: 1px solid var(--color-border);
    margin-top: var(--space-xs);
    padding-top: var(--space-sm);
    color: var(--color-error);
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: 0.625rem 1.25rem;
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 0.9375rem;
    line-height: 1.4;
    transition: all var(--transition-fast);
    text-decoration: none;
    min-height: 44px; /* Touch target */
    min-width: 44px;
    white-space: nowrap;
}

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

.btn-outline {
    background: transparent;
    color: var(--color-primary);
    border-color: var(--color-primary);
}
.btn-outline:hover {
    background: var(--color-primary);
    color: white;
}

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

.btn-danger {
    background: var(--color-error);
    border-color: var(--color-error);
    color: white;
}
.btn-danger:hover {
    background: #B91C1C;
    border-color: #B91C1C;
}

.btn-sm { padding: 0.375rem 0.75rem; font-size: 0.8125rem; min-height: 36px; }
.btn-lg { padding: 0.875rem 1.75rem; font-size: 1.0625rem; }
.btn-full { width: 100%; }

/* ===== Hero ===== */
.hero {
    background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-primary) 50%, var(--color-accent) 100%);
    color: white;
    padding: var(--space-3xl) 0;
    text-align: center;
}

.hero h1 {
    font-size: clamp(1.75rem, 5vw, 2.75rem);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--space-md);
}

.hero-subtitle {
    font-size: clamp(1rem, 2.5vw, 1.25rem);
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto var(--space-xl);
    line-height: 1.6;
}

.hero-actions {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
}

.hero-actions .btn {
    min-width: 160px;
}

.hero-actions .btn-outline {
    border-color: white;
    color: white;
}
.hero-actions .btn-outline:hover {
    background: white;
    color: var(--color-primary-dark);
}

/* ===== Subject Grid ===== */
.subject-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-lg);
    padding: var(--space-xl) 0;
}

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

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

.subject-card {
    display: flex;
    flex-direction: column;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
    text-decoration: none;
    color: inherit;
    min-height: 200px;
}

.subject-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--card-color, var(--color-primary));
}

.subject-card:hover {
    border-color: var(--card-color, var(--color-primary));
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.subject-card h3 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
    color: var(--color-text);
}

.subject-card p {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
    flex: 1;
    line-height: 1.5;
}

.subject-icon {
    font-size: 2.5rem;
    margin-bottom: var(--space-md);
}

.subject-meta {
    display: flex;
    gap: var(--space-sm);
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    margin-top: var(--space-md);
}

.subject-progress {
    margin-top: var(--space-md);
}

.subject-progress .progress-bar {
    margin-bottom: var(--space-xs);
}

.subject-progress span {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
}

.subject-arrow {
    position: absolute;
    top: var(--space-xl);
    right: var(--space-xl);
    font-size: 1.25rem;
    color: var(--color-text-muted);
    transition: transform var(--transition-fast);
}

.subject-card:hover .subject-arrow {
    transform: translateX(4px);
}

/* ===== Features ===== */
.features {
    padding: var(--space-3xl) 0;
}

.features h2 {
    text-align: center;
    font-size: clamp(1.5rem, 4vw, 2rem);
    margin-bottom: var(--space-2xl);
}

.feature-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-lg);
}

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

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

.feature-card {
    text-align: center;
    padding: var(--space-xl);
    background: var(--color-surface);
    border-radius: var(--radius-xl);
    border: 1px solid var(--color-border);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: var(--space-md);
}

.feature-card h3 {
    font-size: 1.0625rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.feature-card p {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
    line-height: 1.5;
}

/* ===== Auth Pages ===== */
.auth-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: calc(100vh - var(--header-height) - 80px);
    padding: var(--space-xl) 0;
}

.auth-container { max-width: 420px; }

.auth-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    box-shadow: var(--shadow-lg);
}

.auth-header {
    text-align: center;
    margin-bottom: var(--space-xl);
}

.auth-header h1 {
    font-size: 1.5rem;
    font-weight: 800;
    margin-bottom: var(--space-xs);
}

.auth-header p {
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
}

.auth-form { display: flex; flex-direction: column; gap: var(--space-md); }

.auth-footer {
    text-align: center;
    margin-top: var(--space-lg);
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-border);
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
}

.auth-footer a { font-weight: 600; }

/* ===== Forms ===== */
.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.form-group label {
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

.form-group input,
.form-group select,
.form-group textarea {
    padding: 0.75rem var(--space-md);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: border-color var(--transition-fast);
    background: var(--color-surface);
    min-height: 48px;
}

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

.form-group textarea {
    min-height: 100px;
    resize: vertical;
}

/* ===== Alerts ===== */
.alert {
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-lg);
    font-size: 0.9375rem;
}

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

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

.alert-warning {
    background: var(--color-warning-bg);
    color: var(--color-warning);
    border: 1px solid #FDE68A;
}

.alert-info {
    background: var(--color-info-bg);
    color: var(--color-info);
    border: 1px solid #93C5FD;
}

/* ===== Progress Bar ===== */
.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--color-surface-alt);
    border-radius: var(--radius-full);
    overflow: hidden;
}

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

/* ===== Difficulty Badges ===== */
.difficulty-badge {
    display: inline-block;
    padding: 0.125rem 0.5rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: capitalize;
}

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

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

.difficulty-advanced {
    background: var(--color-error-bg);
    color: var(--color-error);
}

/* ===== Dashboard ===== */
.dashboard {
    padding: var(--space-xl) 0 var(--space-3xl);
}

.dashboard-header {
    margin-bottom: var(--space-xl);
}

.dashboard-header h1 {
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 800;
}

.dashboard-header p {
    color: var(--color-text-secondary);
    font-size: 1.0625rem;
    margin-top: var(--space-xs);
}

/* Stats Row */
.stats-row {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
    margin-bottom: var(--space-xl);
}

@media (min-width: 768px) {
    .stats-row { grid-template-columns: repeat(4, 1fr); }
}

.stat-card {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
}

.stat-icon { font-size: 1.75rem; }

.stat-value {
    display: block;
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--color-text);
}

.stat-label {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
}

/* Level Progress */
.level-progress {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    margin-bottom: var(--space-xl);
}

.level-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: var(--space-sm);
    font-weight: 600;
    font-size: 0.9375rem;
}

.level-progress .progress-bar {
    height: 12px;
    margin-bottom: var(--space-xs);
}

.level-detail {
    display: flex;
    justify-content: space-between;
    font-size: 0.8125rem;
    color: var(--color-text-muted);
}

/* Continue Section */
.continue-section {
    margin-bottom: var(--space-xl);
}

.continue-section h2 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
}

.continue-card {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    text-decoration: none;
    color: inherit;
    transition: all var(--transition-fast);
}

.continue-card:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-md);
}

.continue-info h3 {
    font-size: 1.0625rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.continue-info .progress-bar {
    margin-bottom: var(--space-xs);
}

.continue-info span {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
}

.continue-arrow {
    font-size: 1.5rem;
    color: var(--color-primary);
    margin-left: auto;
}

/* Subject Section */
.subjects-section {
    margin-bottom: var(--space-xl);
}

.subjects-section h2 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
}

/* Dashboard Grid */
.dashboard-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-xl);
}

@media (min-width: 768px) {
    .dashboard-grid { grid-template-columns: repeat(2, 1fr); }
}

.activity-section h2,
.badges-section h2 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
}

.activity-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.activity-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
}

.activity-icon { font-size: 1.25rem; }

.activity-item a {
    flex: 1;
    font-weight: 500;
    font-size: 0.9375rem;
}

.activity-status {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
}

/* Badges */
.badge-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-md);
}

.badge-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: var(--space-md);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    transition: all var(--transition-fast);
}

.badge-item:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-sm);
}

.badge-icon {
    font-size: 2rem;
    margin-bottom: var(--space-xs);
}

.badge-name {
    font-size: 0.8125rem;
    font-weight: 600;
}

.badge-date {
    font-size: 0.6875rem;
    color: var(--color-text-muted);
    margin-top: var(--space-xs);
}

/* ===== Subject Detail ===== */
.subject-detail {
    padding-bottom: var(--space-3xl);
}

.subject-hero {
    background: linear-gradient(135deg, var(--hero-color, var(--color-primary-dark)), var(--hero-color, var(--color-primary)));
    color: white;
    padding: var(--space-2xl) 0;
    margin-bottom: var(--space-xl);
}

.back-link {
    display: inline-block;
    color: rgba(255,255,255,0.8);
    font-size: 0.9375rem;
    margin-bottom: var(--space-lg);
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.back-link:hover {
    color: white;
    background: rgba(255,255,255,0.1);
}

.subject-hero-content {
    max-width: 600px;
}

.subject-icon-large {
    font-size: 4rem;
    margin-bottom: var(--space-md);
}

.subject-hero h1 {
    font-size: clamp(1.5rem, 4vw, 2.25rem);
    font-weight: 800;
    margin-bottom: var(--space-sm);
}

.subject-hero p {
    font-size: 1.0625rem;
    opacity: 0.9;
    line-height: 1.6;
}

.learning-paths {
    margin-bottom: var(--space-xl);
}

.learning-paths h2 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
}

.path-list {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-md);
}

@media (min-width: 768px) {
    .path-list { grid-template-columns: repeat(2, 1fr); }
}

.path-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
}

.path-card h3 {
    font-size: 1.0625rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.path-card p {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-md);
}

.path-meta {
    display: flex;
    gap: var(--space-md);
    font-size: 0.8125rem;
}

/* Modules List */
.modules-list h2 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
}

.module-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    margin-bottom: var(--space-md);
}

.module-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-sm);
}

.module-header h3 a {
    font-size: 1.125rem;
    font-weight: 700;
}

.lesson-count {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    white-space: nowrap;
}

.module-card p {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-md);
}

/* ===== Module Detail ===== */
.module-detail {
    padding: var(--space-xl) 0 var(--space-3xl);
}

.module-detail h1 {
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 800;
    margin-bottom: var(--space-sm);
}

.module-detail > .container > p {
    color: var(--color-text-secondary);
    margin-bottom: var(--space-xl);
    font-size: 1.0625rem;
}

.lesson-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.lesson-item {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    transition: all var(--transition-fast);
}

.lesson-item:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-sm);
}

.lesson-item.status-completed {
    background: var(--color-success-bg);
    border-color: #A7F3D0;
}

.lesson-status {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.lesson-info { flex: 1; }

.lesson-info h3 {
    font-size: 1.0625rem;
    font-weight: 600;
    margin-bottom: var(--space-xs);
}

.lesson-info h3 a { color: var(--color-text); }
.lesson-info h3 a:hover { color: var(--color-primary); }

.lesson-meta {
    display: flex;
    gap: var(--space-md);
    font-size: 0.8125rem;
    color: var(--color-text-muted);
}

.lesson-badge {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--color-success);
    white-space: nowrap;
}

/* ===== Lesson Detail ===== */
.lesson-detail {
    padding: var(--space-xl) 0 var(--space-3xl);
}

.lesson-container {
    max-width: 900px;
}

.lesson-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-xl);
}

@media (min-width: 1024px) {
    .lesson-layout { grid-template-columns: 1fr 300px; }
}

.lesson-header {
    margin-bottom: var(--space-xl);
}

.lesson-header h1 {
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 800;
    margin-bottom: var(--space-sm);
}

.lesson-objectives {
    background: var(--color-primary-bg);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    margin-bottom: var(--space-xl);
}

.lesson-objectives h2 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
    color: var(--color-primary-dark);
}

.objectives-content {
    font-size: 0.9375rem;
    line-height: 1.7;
}

.lesson-content {
    font-size: 1.0625rem;
    line-height: 1.8;
    margin-bottom: var(--space-xl);
}

.lesson-content h2 {
    font-size: 1.375rem;
    font-weight: 700;
    margin: var(--space-xl) 0 var(--space-md);
}

.lesson-content h3 {
    font-size: 1.125rem;
    font-weight: 700;
    margin: var(--space-lg) 0 var(--space-sm);
}

.lesson-content p {
    margin-bottom: var(--space-md);
}

.lesson-content ul, .lesson-content ol {
    margin: var(--space-md) 0;
    padding-left: var(--space-xl);
}

.lesson-content ul { list-style: disc; }
.lesson-content ol { list-style: decimal; }

.lesson-content li {
    margin-bottom: var(--space-sm);
}

.lesson-content blockquote {
    border-left: 4px solid var(--color-primary);
    padding: var(--space-md) var(--space-lg);
    margin: var(--space-lg) 0;
    background: var(--color-surface-alt);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    font-style: italic;
}

.lesson-content pre {
    background: var(--color-text);
    color: var(--color-bg);
    padding: var(--space-lg);
    border-radius: var(--radius-md);
    overflow-x: auto;
    font-size: 0.875rem;
    margin: var(--space-lg) 0;
}

.lesson-content code {
    background: var(--color-surface-alt);
    padding: 0.125rem 0.375rem;
    border-radius: var(--radius-sm);
    font-size: 0.875em;
    font-family: var(--font-mono);
}

.lesson-content table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--space-lg) 0;
}

.lesson-content th, .lesson-content td {
    padding: var(--space-sm) var(--space-md);
    border: 1px solid var(--color-border);
    text-align: left;
}

.lesson-content th {
    background: var(--color-surface-alt);
    font-weight: 600;
}

.lesson-section {
    margin: var(--space-xl) 0;
    padding: var(--space-lg);
    background: var(--color-surface-alt);
    border-radius: var(--radius-lg);
}

.lesson-section h2 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
}

/* Lesson Navigation */
.lesson-navigation {
    display: flex;
    justify-content: space-between;
    gap: var(--space-md);
    margin-top: var(--space-xl);
    padding-top: var(--space-xl);
    border-top: 1px solid var(--color-border);
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-lg);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 0.9375rem;
    transition: all var(--transition-fast);
    flex: 1;
    justify-content: center;
}

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

.nav-btn.prev { text-align: left; }
.nav-btn.next { text-align: right; }

/* Lesson Sidebar */
.lesson-sidebar {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.sidebar-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
}

.sidebar-card h3 {
    font-size: 0.9375rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
}

.sidebar-card .progress-bar {
    margin-bottom: var(--space-xs);
}

.sidebar-card span {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
}

.sidebar-card .btn + .btn {
    margin-top: var(--space-sm);
}

.sidebar-card textarea {
    width: 100%;
    padding: var(--space-sm) var(--space-md);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 0.9375rem;
    resize: vertical;
    margin-bottom: var(--space-sm);
    min-height: 80px;
}

.sidebar-card textarea:focus {
    outline: none;
    border-color: var(--color-primary);
}

/* ===== Breadcrumb ===== */
.breadcrumb {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 0.875rem;
    margin-bottom: var(--space-lg);
    flex-wrap: wrap;
}

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

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

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

.breadcrumb > *:last-child {
    color: var(--color-text-secondary);
    font-weight: 500;
}

/* ===== Glossary ===== */
.glossary-page {
    padding: var(--space-xl) 0 var(--space-3xl);
}

.glossary-page h1 {
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 800;
    margin-bottom: var(--space-lg);
}

.glossary-controls {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
    margin-bottom: var(--space-xl);
}

@media (min-width: 768px) {
    .glossary-controls { flex-direction: row; }
}

.search-form {
    display: flex;
    gap: var(--space-sm);
    flex: 1;
}

.search-form input {
    flex: 1;
    padding: 0.75rem var(--space-md);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 1rem;
    min-height: 48px;
}

.search-form input:focus {
    outline: none;
    border-color: var(--color-primary);
}

.filter-group {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.filter-group select {
    padding: 0.5rem var(--space-md);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 0.9375rem;
    min-height: 40px;
}

.glossary-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-md);
}

@media (min-width: 768px) {
    .glossary-grid { grid-template-columns: repeat(2, 1fr); }
}

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

.glossary-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    transition: all var(--transition-fast);
}

.glossary-card:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-sm);
}

.glossary-term h3 {
    font-size: 1.0625rem;
    font-weight: 700;
    margin-bottom: var(--space-xs);
}

.pronunciation {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
}

.glossary-definition {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin: var(--space-sm) 0;
}

.glossary-example {
    border-left: 3px solid var(--color-primary);
    padding: var(--space-sm) var(--space-md);
    margin: var(--space-sm) 0;
    background: var(--color-primary-bg);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    font-size: 0.875rem;
    font-style: italic;
}

.glossary-meta {
    margin-top: var(--space-sm);
}

/* ===== Flashcards ===== */
.flashcards-page {
    padding: var(--space-xl) 0 var(--space-3xl);
}

.flashcards-page h1 {
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 800;
    margin-bottom: var(--space-lg);
}

.flashcard-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-xl);
    flex-wrap: wrap;
    gap: var(--space-md);
}

.flashcard-controls select {
    padding: 0.5rem var(--space-md);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 0.9375rem;
    min-height: 40px;
}

.fc-stats {
    display: flex;
    gap: var(--space-lg);
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
}

.flashcard-area {
    max-width: 600px;
    margin: 0 auto;
}

.flashcard {
    perspective: 1000px;
    height: 300px;
    cursor: pointer;
    margin-bottom: var(--space-xl);
}

.flashcard > div {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: var(--color-surface);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    text-align: center;
    transition: transform 0.6s;
}

.flashcard .flashcard-front {
    transform: rotateY(0deg);
}

.flashcard .flashcard-back {
    transform: rotateY(180deg);
}

.flashcard.flipped .flashcard-front {
    transform: rotateY(180deg);
}

.flashcard.flipped .flashcard-back {
    transform: rotateY(0deg);
}

.fc-label {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-muted);
    margin-bottom: var(--space-md);
}

.flashcard p {
    font-size: 1.25rem;
    font-weight: 600;
    line-height: 1.5;
}

.flashcard-actions {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
}

.flashcard-actions .btn {
    flex: 1;
    max-width: 180px;
}

.fc-hint {
    text-align: center;
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    margin-top: var(--space-md);
}

/* ===== Quizzes ===== */
.quizzes-page {
    padding: var(--space-xl) 0 var(--space-3xl);
}

.quizzes-page h1 {
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 800;
    margin-bottom: var(--space-lg);
}

.quiz-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.quiz-card {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-lg);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    flex-wrap: wrap;
}

.quiz-info h3 {
    font-size: 1.0625rem;
    font-weight: 700;
    margin-bottom: var(--space-xs);
}

.quiz-meta {
    display: flex;
    gap: var(--space-md);
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    flex-wrap: wrap;
}

/* Quiz Take */
.quiz-take {
    padding: var(--space-xl) 0 var(--space-3xl);
}

.quiz-container { max-width: 700px; }

.quiz-header {
    margin-bottom: var(--space-xl);
}

.quiz-header h1 {
    font-size: clamp(1.25rem, 3vw, 1.75rem);
    font-weight: 800;
    margin-bottom: var(--space-sm);
}

.quiz-form {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.question-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
}

.question-number {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    margin-bottom: var(--space-xs);
}

.question-type {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-primary);
    background: var(--color-primary-bg);
    padding: 0.125rem 0.5rem;
    border-radius: var(--radius-full);
    margin-bottom: var(--space-md);
}

.question-card h3 {
    font-size: 1.0625rem;
    font-weight: 600;
    margin-bottom: var(--space-lg);
    line-height: 1.5;
}

.answer-choices {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.choice-label {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md) var(--space-lg);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    min-height: 52px;
}

.choice-label:hover {
    border-color: var(--color-primary);
    background: var(--color-primary-bg);
}

.choice-label input[type="radio"] {
    width: 20px;
    height: 20px;
    accent-color: var(--color-primary);
}

.choice-text {
    font-size: 1rem;
    flex: 1;
}

.short-answer-input {
    width: 100%;
    padding: 0.75rem var(--space-md);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 1rem;
    min-height: 48px;
}

.short-answer-input:focus {
    outline: none;
    border-color: var(--color-primary);
}

.quiz-submit {
    text-align: center;
    padding: var(--space-xl) 0;
}

/* Quiz Results */
.quiz-results {
    margin-top: var(--space-xl);
}

.result-card {
    text-align: center;
    padding: var(--space-2xl);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
}

.result-card.passed {
    background: var(--color-success-bg);
    border-color: #A7F3D0;
}

.result-card.failed {
    background: var(--color-warning-bg);
    border-color: #FDE68A;
}

.result-card h2 {
    font-size: 1.5rem;
    font-weight: 800;
    margin-bottom: var(--space-lg);
}

.score-display {
    margin-bottom: var(--space-md);
}

.score-value {
    display: block;
    font-size: 3rem;
    font-weight: 800;
    color: var(--color-primary);
}

.score-detail {
    font-size: 1rem;
    color: var(--color-text-secondary);
}

/* ===== Profile ===== */
.profile-page {
    padding: var(--space-xl) 0 var(--space-3xl);
}

.profile-page h1 {
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 800;
    margin-bottom: var(--space-xl);
}

.profile-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-xl);
}

@media (min-width: 768px) {
    .profile-grid { grid-template-columns: repeat(2, 1fr); }
}

.profile-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
}

.profile-avatar {
    text-align: center;
    margin-bottom: var(--space-lg);
}

.avatar-letter-large {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 80px;
    height: 80px;
    border-radius: var(--radius-full);
    background: var(--color-primary);
    color: white;
    font-size: 2rem;
    font-weight: 800;
}

.profile-card > h2 {
    text-align: center;
    font-size: 1.25rem;
    font-weight: 700;
}

.profile-card > p {
    text-align: center;
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
    margin-bottom: var(--space-lg);
}

.profile-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
}

.profile-stat {
    text-align: center;
    padding: var(--space-md);
    background: var(--color-surface-alt);
    border-radius: var(--radius-md);
}

.profile-stat .stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 800;
}

.profile-stat .stat-label {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
}

.profile-card h3 {
    font-size: 1.0625rem;
    font-weight: 700;
    margin-bottom: var(--space-lg);
}

.settings-form {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.lang-options {
    display: flex;
    gap: var(--space-lg);
}

.lang-options label {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    cursor: pointer;
}

.profile-actions {
    display: flex;
    gap: var(--space-md);
    margin-top: var(--space-xl);
    padding-top: var(--space-xl);
    border-top: 1px solid var(--color-border);
}

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

/* ===== Empty State ===== */
.empty-state {
    text-align: center;
    padding: var(--space-3xl) var(--space-xl);
    color: var(--color-text-muted);
}

.empty-state p {
    font-size: 1.0625rem;
}

.empty-text {
    text-align: center;
    color: var(--color-text-muted);
    padding: var(--space-xl);
}

/* ===== Error Page ===== */
.error-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: calc(100vh - var(--header-height) - 80px);
}

.error-card {
    text-align: center;
    padding: var(--space-3xl);
}

.error-card h1 {
    font-size: 5rem;
    font-weight: 800;
    color: var(--color-primary);
    line-height: 1;
    margin-bottom: var(--space-md);
}

.error-card h2 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.error-card p {
    color: var(--color-text-secondary);
    margin-bottom: var(--space-xl);
}

/* ===== Footer ===== */
.site-footer {
    background: var(--color-primary-dark);
    color: rgba(255,255,255,0.8);
    padding: var(--space-2xl) 0 var(--space-lg);
    margin-top: auto;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-xl);
    margin-bottom: var(--space-xl);
}

@media (min-width: 768px) {
    .footer-grid { grid-template-columns: 2fr 1fr 1fr; }
}

.footer-section h3 {
    color: white;
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
}

.footer-section h4 {
    color: white;
    font-size: 0.9375rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-md);
}

.footer-section p {
    font-size: 0.9375rem;
    line-height: 1.6;
}

.footer-section ul {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.footer-section a {
    color: rgba(255,255,255,0.7);
    font-size: 0.9375rem;
    transition: color var(--transition-fast);
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    padding-top: var(--space-lg);
    border-top: 1px solid rgba(255,255,255,0.1);
    text-align: center;
    font-size: 0.8125rem;
}

/* ===== Modal ===== */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: var(--space-lg);
}

.modal {
    background: var(--color-surface);
    border-radius: var(--radius-xl);
    max-width: 500px;
    width: 100%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: var(--shadow-xl);
}

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

.modal-header h3 {
    font-size: 1.125rem;
    font-weight: 700;
}

.modal-close {
    width: 36px;
    height: 36px;
    border: none;
    background: none;
    font-size: 1.5rem;
    color: var(--color-text-muted);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
}

.modal-close:hover {
    background: var(--color-surface-alt);
    color: var(--color-text);
}

.modal-body {
    padding: var(--space-xl);
}

/* ===== Toast ===== */
.toast-container {
    position: fixed;
    bottom: var(--space-xl);
    right: var(--space-xl);
    z-index: 1001;
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.toast {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-md) var(--space-lg);
    box-shadow: var(--shadow-lg);
    font-size: 0.9375rem;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

/* ===== Admin Styles ===== */
.admin-layout {
    display: flex;
    min-height: 100vh;
}

.admin-sidebar {
    width: var(--sidebar-width);
    background: var(--color-primary-dark);
    color: white;
    padding: var(--space-xl) 0;
    flex-shrink: 0;
    position: sticky;
    top: 0;
    height: 100vh;
    overflow-y: auto;
}

.sidebar-header {
    padding: 0 var(--space-xl);
    margin-bottom: var(--space-xl);
}

.sidebar-header .logo {
    color: white;
    font-size: 1.125rem;
}

.admin-badge {
    display: inline-block;
    font-size: 0.6875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    background: rgba(255,255,255,0.15);
    padding: 0.125rem 0.5rem;
    border-radius: var(--radius-full);
    margin-top: var(--space-xs);
}

.admin-sidebar nav {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
    padding: 0 var(--space-md);
}

.sidebar-link {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-md);
    color: rgba(255,255,255,0.7);
    font-weight: 500;
    font-size: 0.9375rem;
    transition: all var(--transition-fast);
}

.sidebar-link:hover, .sidebar-link.active {
    background: rgba(255,255,255,0.1);
    color: white;
}

.sidebar-link .icon {
    font-size: 1.125rem;
    width: 24px;
    text-align: center;
}

.admin-content {
    flex: 1;
    padding: var(--space-xl) var(--space-2xl);
    min-width: 0;
}

.admin-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-xl);
}

.admin-header h1 {
    font-size: 1.5rem;
    font-weight: 800;
}

.admin-stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
}

@media (min-width: 768px) {
    .admin-stats-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (min-width: 1024px) {
    .admin-stats-grid { grid-template-columns: repeat(6, 1fr); }
}

.admin-stat-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
}

.admin-stat-card .stat-icon { font-size: 1.5rem; margin-bottom: var(--space-sm); }
.admin-stat-card .stat-value { font-size: 1.5rem; font-weight: 800; }
.admin-stat-card .stat-label { font-size: 0.8125rem; color: var(--color-text-muted); }

/* Admin Table */
.admin-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    font-size: 0.9375rem;
}

.admin-table thead {
    background: var(--color-surface-alt);
}

.admin-table th {
    padding: var(--space-md) var(--space-lg);
    text-align: left;
    font-weight: 600;
    font-size: 0.8125rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    border-bottom: 1px solid var(--color-border);
}

.admin-table td {
    padding: var(--space-md) var(--space-lg);
    border-bottom: 1px solid var(--color-border);
}

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

.admin-table .btn + .btn {
    margin-left: var(--space-xs);
}

.admin-toolbar {
    margin-bottom: var(--space-lg);
}

.admin-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
}

.import-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-xl);
    margin: var(--space-xl) 0;
}

@media (min-width: 768px) {
    .import-grid { grid-template-columns: repeat(2, 1fr); }
}

.import-section h3 {
    font-size: 1.0625rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
}

.import-section form {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.export-links {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.import-schema {
    margin-top: var(--space-xl);
    padding-top: var(--space-xl);
    border-top: 1px solid var(--color-border);
}

.import-schema pre {
    background: var(--color-surface-alt);
    padding: var(--space-lg);
    border-radius: var(--radius-md);
    font-size: 0.8125rem;
    overflow-x: auto;
    line-height: 1.6;
}

/* Status Badges */
.status-badge {
    display: inline-block;
    padding: 0.125rem 0.5rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
}

.status-badge.published, .status-badge.active {
    background: var(--color-success-bg);
    color: var(--color-success);
}

.status-badge.draft, .status-badge.inactive {
    background: var(--color-warning-bg);
    color: var(--color-warning);
}

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

.role-badge {
    display: inline-block;
    padding: 0.125rem 0.5rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
    background: var(--color-info-bg);
    color: var(--color-info);
}

/* ===== Responsive Adjustments ===== */
/* ===== 2026 Learner Experience ===== */
.page-heading { max-width: 760px; margin-bottom: var(--space-xl); }
.page-heading h1 { font-size: clamp(1.65rem, 4vw, 2.25rem); line-height: 1.3; margin-bottom: var(--space-sm); }
.page-heading > p:last-child, .section-intro, .section-heading-row p { color: var(--color-text-secondary); font-size: 1rem; }
.centered-heading { text-align: center; margin-inline: auto; }
.eyebrow, .card-kicker, .path-step, .lesson-sequence {
    color: var(--color-primary-dark); font-size: .84rem; font-weight: 750; letter-spacing: .02em; margin-bottom: var(--space-xs);
}
.section-heading-row { display: flex; align-items: end; justify-content: space-between; gap: var(--space-md); margin-bottom: var(--space-lg); }
.section-heading-row h2 { font-size: 1.35rem; line-height: 1.35; }

/* Navigation */
.menu-toggle { display: none; width: 48px; height: 48px; border: 1px solid var(--color-border); background: white; border-radius: var(--radius-md); align-items: center; justify-content: center; flex-direction: column; gap: 5px; }
.menu-toggle span { display: block; width: 22px; height: 2px; background: var(--color-text); border-radius: 2px; }
.mobile-menu { background: white; border-top: 1px solid var(--color-border); box-shadow: var(--shadow-md); }
.mobile-menu nav { padding-block: var(--space-sm) var(--space-md); display: grid; }
.mobile-menu a { color: var(--color-text); font-weight: 650; min-height: 48px; display: flex; align-items: center; padding-inline: var(--space-sm); border-radius: var(--radius-md); }
.mobile-menu a:hover { background: var(--color-primary-bg); }
.mobile-menu .mobile-menu-primary { color: var(--color-primary-dark); }
.mobile-bottom-nav { display: none; }

/* Home */
.hero { text-align: left; padding: clamp(3rem, 8vw, 6rem) 0; background: linear-gradient(125deg, #173F2F 0%, #236B4B 68%, #2A7D63 100%); }
.hero-content { max-width: 760px; }
.hero .eyebrow { color: #D6F0E2; }
.hero h1 { max-width: 700px; font-size: clamp(2rem, 6vw, 3.5rem); }
.hero-subtitle { margin-inline: 0; max-width: 670px; opacity: .95; }
.hero-actions { justify-content: flex-start; }
.hero-actions .btn-primary { background: white; color: var(--color-primary-dark); border-color: white; }
.trust-strip { background: white; border-bottom: 1px solid var(--color-border); padding: var(--space-xl) 0; }
.trust-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-xl); }
.trust-grid article { display: flex; gap: var(--space-md); align-items: flex-start; }
.trust-grid article > span { color: var(--color-primary-dark); background: var(--color-primary-bg); min-width: 48px; height: 48px; border-radius: var(--radius-full); display: grid; place-items: center; font-weight: 800; }
.trust-grid h2 { font-size: 1rem; line-height: 1.4; margin-bottom: .2rem; }
.trust-grid p { color: var(--color-text-secondary); font-size: .9rem; line-height: 1.55; }
.subjects-preview { padding: var(--space-2xl) 0; }
.subjects-preview > .container > h2 { font-size: 1.65rem; }
.card-action { margin-top: var(--space-lg); color: var(--color-primary-dark); font-weight: 700; }
.home-cta { padding: 0 0 var(--space-3xl); }
.home-cta-card { background: var(--color-primary-bg); border: 1px solid #C6E1D2; border-radius: var(--radius-xl); padding: clamp(1.5rem, 5vw, 3.5rem); text-align: center; }
.home-cta-card h2 { font-size: 1.6rem; }
.home-cta-card p { color: var(--color-text-secondary); margin: .4rem 0 1.25rem; }
.home-cta-card small { display: block; color: var(--color-text-secondary); margin-top: .75rem; }

/* Authentication */
.auth-container { max-width: 500px; }
.auth-card { box-shadow: var(--shadow-sm); padding: clamp(1.25rem, 5vw, 2.5rem); }
.auth-header h1 { font-size: 1.7rem; }
.form-group label { font-size: .96rem; color: var(--color-text); }
.form-group small, .auth-footer small, .form-note { color: var(--color-text-secondary); font-size: .85rem; line-height: 1.55; }
.form-note { padding: var(--space-sm) var(--space-md); background: var(--color-surface-alt); border-radius: var(--radius-md); }
.password-field { position: relative; }
.password-field input { width: 100%; padding-right: 7.5rem; }
.password-toggle { position: absolute; right: 5px; top: 5px; min-height: 38px; padding: 0 .7rem; border: 0; background: var(--color-primary-bg); color: var(--color-primary-dark); border-radius: var(--radius-sm); font-size: .82rem; font-weight: 700; }
.alert { font-size: 1rem; line-height: 1.6; }

/* Dashboard and progress */
.continue-section { margin-bottom: var(--space-2xl); }
.continue-card-primary { border: 2px solid #BEDBCB; padding: clamp(1rem, 4vw, 1.75rem); flex-wrap: wrap; }
.continue-card-primary .continue-info { flex: 1 1 280px; }
.continue-card-primary .btn { margin-left: auto; }
.continue-icon { width: 52px; height: 52px; border-radius: var(--radius-full); background: var(--color-primary-bg); color: var(--color-primary-dark); display: grid; place-items: center; font-weight: 800; flex: 0 0 auto; }
.onboarding-card p { color: var(--color-text-secondary); }
.progress-summary { background: #F2F5F2; border: 1px solid var(--color-border); border-radius: var(--radius-xl); padding: var(--space-lg); margin-bottom: var(--space-2xl); }
.compact-stats .stat-card { background: rgba(255,255,255,.88); padding: var(--space-md); }
.compact-stats .stat-icon { width: 36px; height: 36px; display: grid; place-items: center; border-radius: var(--radius-full); color: var(--color-primary-dark); background: var(--color-primary-bg); font-size: 1rem; font-weight: 800; }
.progress-summary .level-progress { margin-bottom: 0; }

/* Discovery */
.subject-card { min-height: 230px; }
.subject-card:focus-visible, .module-card-link:focus-visible, .lesson-item:focus-visible, .path-module-link:focus-visible { outline: 3px solid #D97706; outline-offset: 3px; }
.path-list { grid-template-columns: 1fr; }
.path-card { padding: clamp(1rem, 3vw, 1.5rem); }
.path-step { display: inline-block; background: var(--color-primary-bg); border-radius: var(--radius-full); padding: .15rem .65rem; }
.path-module-list { display: grid; gap: var(--space-sm); margin-top: var(--space-lg); }
.path-module-link { min-height: 64px; display: flex; align-items: center; gap: var(--space-md); padding: var(--space-md); color: var(--color-text); background: var(--color-surface-alt); border: 1px solid transparent; border-radius: var(--radius-md); }
.path-module-link:hover { background: var(--color-primary-bg); border-color: #BEDBCB; }
.module-step-number { width: 32px; height: 32px; display: grid; place-items: center; flex: none; border-radius: var(--radius-full); background: white; color: var(--color-primary-dark); font-weight: 800; }
.path-module-copy { flex: 1; display: grid; }
.path-module-copy small { color: var(--color-text-secondary); }
.status-pill { white-space: nowrap; border-radius: var(--radius-full); padding: .18rem .6rem; font-size: .75rem; font-weight: 750; background: #ECEFED; color: var(--color-text-secondary); }
.status-pill.status-in_progress { background: var(--color-warning-bg); color: #92400E; }
.status-pill.status-completed { background: var(--color-success-bg); color: #047857; }
.module-card-link { display: block; color: inherit; }
.module-card-footer { display: flex; justify-content: space-between; color: var(--color-text-secondary); font-size: .88rem; }
.module-page-header { max-width: 760px; margin-bottom: var(--space-xl); }
.module-page-header > p { color: var(--color-text-secondary); font-size: 1rem; }
.module-progress-summary { margin-top: var(--space-lg); background: white; border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: var(--space-md); }
.module-progress-summary > span { display: block; font-size: .9rem; font-weight: 700; margin-bottom: .4rem; }
.lesson-item { color: inherit; min-height: 96px; }
.lesson-sequence { display: block; margin: 0; }
.lesson-open { color: var(--color-primary); font-size: 1.4rem; }

/* Lesson reading */
.lesson-container { max-width: 1100px; }
.lesson-main { min-width: 0; }
.lesson-content { max-width: 720px; font-size: 1.1rem; line-height: 1.9; overflow-wrap: anywhere; }
.lesson-content p, .lesson-content li { max-width: 68ch; }
.lesson-content a { text-decoration: underline; text-underline-offset: 3px; }
.lesson-content table { display: block; overflow-x: auto; }
.lesson-sidebar { align-self: start; }
.action-status { min-height: 1.5em; margin-top: var(--space-xs); color: var(--color-text-secondary); font-size: .85rem; }
.sidebar-card h3 { text-transform: none; letter-spacing: 0; color: var(--color-text); font-size: 1rem; }

/* Filters, empty states, quiz and review */
.compact-filter { display: flex; align-items: center; gap: var(--space-sm); flex-wrap: wrap; margin-bottom: var(--space-lg); }
.compact-filter label { font-weight: 700; }
.compact-filter select { min-height: 48px; }
.glossary-filter-form { flex-wrap: wrap; }
.glossary-filter-form .filter-group { flex: 1 1 260px; }
.glossary-filter-form select { flex: 1; }
.results-summary { display: flex; justify-content: space-between; gap: var(--space-md); margin-bottom: var(--space-md); color: var(--color-text-secondary); }
.results-summary a { font-weight: 700; text-decoration: underline; }
.empty-state h2 { color: var(--color-text); font-size: 1.3rem; margin-bottom: .35rem; }
.empty-state p { max-width: 520px; margin: 0 auto var(--space-lg); color: var(--color-text-secondary); }
.empty-icon { width: 64px; height: 64px; display: grid; place-items: center; margin: 0 auto var(--space-md); border-radius: var(--radius-full); background: var(--color-primary-bg); color: var(--color-primary-dark); font-size: 1.6rem; font-weight: 800; }
.compact-empty { padding: var(--space-lg); }
.quiz-header > p { color: var(--color-text-secondary); margin-bottom: var(--space-md); }
.quiz-progress-wrap { position: sticky; top: calc(var(--header-height) + 1px); z-index: 20; background: var(--color-bg); padding: var(--space-sm) 0 var(--space-md); margin-bottom: var(--space-md); }
.quiz-progress-label { display: flex; justify-content: space-between; gap: var(--space-md); color: var(--color-text-secondary); font-size: .9rem; margin-bottom: .35rem; }
.question-card { padding: clamp(1rem, 5vw, 2rem); }
.question-card h2 { font-size: 1.25rem; line-height: 1.65; margin-bottom: var(--space-lg); }
.question-card legend { float: left; }
.choice-label:has(input:checked) { border-color: var(--color-primary); background: var(--color-primary-bg); box-shadow: 0 0 0 1px var(--color-primary); }
.choice-marker { width: 32px; height: 32px; display: grid; place-items: center; flex: none; border-radius: var(--radius-full); background: var(--color-surface-alt); font-weight: 800; }
.choice-label:has(input:checked) .choice-marker { background: var(--color-primary); color: white; }
.question-error { color: var(--color-error); font-weight: 700; margin-top: var(--space-md); }
.quiz-step-actions { display: flex; justify-content: space-between; gap: var(--space-md); }
.quiz-step-actions #quiz-next { margin-left: auto; }
.quiz-review { background: white; border: 1px solid var(--color-border); border-radius: var(--radius-xl); padding: clamp(1rem, 5vw, 2rem); }
.quiz-review h2 { font-size: 1.4rem; margin-bottom: .4rem; }
.review-list { display: grid; gap: var(--space-sm); margin: var(--space-lg) 0; }
.review-edit { width: 100%; min-height: 56px; border: 1px solid var(--color-border); border-radius: var(--radius-md); background: var(--color-surface-alt); display: grid; grid-template-columns: 32px 1fr auto; align-items: center; gap: var(--space-sm); padding: var(--space-sm) var(--space-md); text-align: left; color: var(--color-text); }
.review-edit strong { font-weight: 600; }
.answer-review-list { display: grid; gap: var(--space-md); margin-top: var(--space-xl); }
.answer-review { background: white; border: 1px solid var(--color-border); border-left: 5px solid var(--color-success); border-radius: var(--radius-lg); padding: var(--space-lg); }
.answer-review.incorrect { border-left-color: var(--color-warning); }
.answer-review h3 { font-size: 1rem; margin-bottom: .5rem; }
.answer-review p { margin-top: .35rem; }
.answer-explanation { background: var(--color-primary-bg); padding: var(--space-md); border-radius: var(--radius-md); }
.result-icon { width: 64px; height: 64px; display: grid; place-items: center; border-radius: var(--radius-full); background: white; margin: 0 auto var(--space-md); font-size: 1.8rem; font-weight: 800; }
.result-actions { display: flex; justify-content: center; flex-wrap: wrap; gap: var(--space-md); margin-top: var(--space-xl); }

/* Flashcards and profile */
.flashcard { position: relative; }
.reveal-answer { display: flex; margin: 0 auto; min-width: 200px; }
.flashcard-actions { flex-wrap: wrap; }
.flashcard-actions .btn { border: 2px solid var(--color-border); background: white; color: var(--color-text); }
.flashcard-actions .confidence-high { border-color: var(--color-primary); color: var(--color-primary-dark); }
.flashcard-actions .confidence-medium { border-color: #D97706; }
.flashcard-actions .confidence-low { border-color: #8B5E3C; }
.success-state { background: white; border: 1px solid var(--color-border); border-radius: var(--radius-xl); }
.profile-summary-heading { text-align: left !important; border-top: 1px solid var(--color-border); padding-top: var(--space-lg); margin-top: var(--space-lg); }
.language-links { display: flex; gap: var(--space-md); }
.language-links .btn { flex: 1; }

/* Glossary: controls, alphabetical bar, sorting, pagination */
.glossary-controls { margin-bottom: var(--space-xl); align-items: flex-start; }
.search-field { display: flex; gap: var(--space-sm); flex: 1 1 100%; }
.search-field input { flex: 1; padding: 0.625rem var(--space-md); border: 2px solid var(--color-border); border-radius: var(--radius-md); font-size: 0.9375rem; min-height: 44px; max-height: 48px; background: var(--color-surface); }
.search-field input:focus { outline: none; border-color: var(--color-primary); box-shadow: 0 0 0 3px var(--color-primary-bg); }
.search-field .btn-search { flex-shrink: 0; }
.filter-rows { margin-top: var(--space-md); }
.filter-row { display: grid; grid-template-columns: 1fr; gap: var(--space-md); }
.filter-group { display: flex; flex-direction: column; gap: var(--space-xs); }
.filter-group label { font-weight: 700; font-size: 0.8125rem; color: var(--color-text-secondary); }
.filter-group select { padding: 0.5rem 2rem 0.5rem var(--space-md); border: 2px solid var(--color-border); border-radius: var(--radius-md); font-size: 0.875rem; min-height: 44px; background: var(--color-surface) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath d='M2.5 4.5l3.5 3.5 3.5-3.5' fill='none' stroke='%2357534E' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") no-repeat right 0.625rem center; -webkit-appearance: none; appearance: none; }
.filter-group select:focus { outline: none; border-color: var(--color-primary); box-shadow: 0 0 0 3px var(--color-primary-bg); }
.alpha-bar { display: flex; flex-wrap: wrap; gap: var(--space-xs); align-items: center; padding: var(--space-sm) 0; border-top: 1px solid var(--color-border); margin-top: var(--space-md); }
.alpha-item { display: inline-flex; align-items: center; justify-content: center; min-width: 32px; height: 32px; padding: 0 var(--space-xs); border-radius: var(--radius-md); font-size: 0.8125rem; font-weight: 600; color: var(--color-text-secondary); text-decoration: none; transition: all var(--transition-fast); }
.alpha-item:hover { background: var(--color-primary-bg); color: var(--color-primary-dark); }
.alpha-item.alpha-active { background: var(--color-primary); color: white; }
.alpha-item.alpha-active:hover { background: var(--color-primary-dark); }
.glossary-subject { font-size: 0.75rem; color: var(--color-text-muted); background: var(--color-surface-alt); padding: 0.125rem 0.5rem; border-radius: var(--radius-full); margin-left: var(--space-sm); }
.glossary-meta { display: flex; align-items: center; gap: var(--space-sm); margin-top: var(--space-sm); flex-wrap: wrap; }

/* Pagination */
.pagination { margin-top: var(--space-xl); }
.pagination-list { display: flex; flex-wrap: wrap; justify-content: center; gap: var(--space-xs); list-style: none; padding: 0; }
.pagination-btn { display: inline-flex; align-items: center; justify-content: center; min-width: 38px; height: 38px; padding: 0 var(--space-sm); border: 2px solid var(--color-border); border-radius: var(--radius-md); font-size: 0.875rem; font-weight: 600; color: var(--color-text-secondary); text-decoration: none; transition: all var(--transition-fast); }
.pagination-btn:hover { border-color: var(--color-primary); color: var(--color-primary); background: var(--color-primary-bg); }
.pagination-current { border-color: var(--color-primary); background: var(--color-primary); color: white; pointer-events: none; }
.pagination-ellipsis { display: inline-flex; align-items: center; justify-content: center; min-width: 38px; height: 38px; color: var(--color-text-muted); }
.pagination-prev, .pagination-next { font-size: 1rem; }

/* Flashcard controls */
.flashcard-filters { width: 100%; }
.flashcard-filters .filter-row { display: grid; grid-template-columns: 1fr; gap: var(--space-md); }
.flashcard-controls { display: flex; flex-direction: column; gap: var(--space-md); margin-bottom: var(--space-xl); }
.fc-stats { display: flex; flex-wrap: wrap; gap: var(--space-lg); font-size: 0.875rem; color: var(--color-text-secondary); justify-content: center; }
.fc-total { color: var(--color-text-muted); }

/* Active filter tags */
.active-filters { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-sm); margin-top: var(--space-sm); }
.active-filters-label { font-weight: 700; font-size: 0.8125rem; color: var(--color-text-secondary); }
.filter-tag { display: inline-flex; align-items: center; gap: var(--space-xs); padding: 0.25rem 0.5rem; background: var(--color-primary-bg); border: 1px solid #C6E1D2; border-radius: var(--radius-full); font-size: 0.8125rem; color: var(--color-primary-dark); font-weight: 600; }
.filter-tag-remove { display: inline-flex; align-items: center; justify-content: center; width: 18px; height: 18px; border-radius: var(--radius-full); color: var(--color-primary); font-size: 0.875rem; line-height: 1; text-decoration: none; transition: all var(--transition-fast); }
.filter-tag-remove:hover { background: var(--color-primary); color: white; }

/* Feedback and modal: explicit hidden rule prevents the blank startup dialog. */
.modal-overlay[hidden], .mobile-menu[hidden] { display: none !important; }
.toast { border-left: 5px solid var(--color-info); max-width: min(360px, calc(100vw - 2rem)); }
.toast-success { border-left-color: var(--color-success); }
.toast-error { border-left-color: var(--color-error); }
.toast-warning { border-left-color: var(--color-warning); }

@media (max-width: 767px) {
    .container { padding: 0 var(--space-md); }
    .admin-content { padding: var(--space-md); }
    .admin-sidebar { display: none; }
    .quiz-card { flex-direction: column; align-items: flex-start; }
    .quiz-card .btn { width: 100%; }
    .flashcard-actions .btn { max-width: none; }
    body:not(.page-login):not(.page-register) { padding-bottom: 72px; }
    .site-header { height: 60px; --header-height: 60px; }
    .header-inner { height: 60px; gap: var(--space-sm); }
    .brand-logo { width: 110px; height: 38px; }
    .menu-toggle { display: flex; }
    .header-register, .header-login, .user-menu { display: none; }
    .lang-toggle { height: 44px; padding-inline: .6rem; }
    .mobile-bottom-nav { position: fixed; z-index: 90; left: 0; right: 0; bottom: 0; height: 68px; padding-bottom: env(safe-area-inset-bottom); background: rgba(255,255,255,.98); border-top: 1px solid var(--color-border); display: grid; grid-template-columns: repeat(4, 1fr); box-shadow: 0 -4px 14px rgba(0,0,0,.05); }
    .mobile-bottom-nav a { color: var(--color-text-secondary); display: flex; flex-direction: column; justify-content: center; align-items: center; line-height: 1.25; gap: 2px; font-size: .7rem; min-width: 0; }
    .mobile-bottom-nav a > span:first-child { font-size: 1.25rem; }
    .mobile-bottom-nav a.active { color: var(--color-primary-dark); font-weight: 800; background: var(--color-primary-bg); }
    .site-footer { padding-bottom: calc(var(--space-lg) + 68px); }
    .hero { padding: var(--space-2xl) 0; }
    .hero-actions { display: grid; }
    .hero-actions .btn { width: 100%; }
    .trust-grid { grid-template-columns: 1fr; gap: var(--space-lg); }
    .subject-grid { gap: var(--space-md); }
    .subject-card { padding: var(--space-lg); min-height: 0; }
    .continue-card-primary { align-items: flex-start; }
    .continue-card-primary .btn { width: 100%; }
    .progress-summary { padding: var(--space-md); }
    .compact-stats { grid-template-columns: 1fr 1fr; gap: var(--space-sm); }
    .compact-stats .stat-card { display: block; }
    .compact-stats .stat-icon { margin-bottom: var(--space-sm); }
    .path-module-link { align-items: flex-start; gap: var(--space-sm); }
    .path-module-link .status-pill { display: none; }
    .module-header { align-items: flex-start; gap: var(--space-sm); }
    .lesson-item { align-items: flex-start; padding: var(--space-md); }
    .lesson-badge { display: none; }
    .lesson-layout { display: flex; flex-direction: column; }
    .lesson-sidebar { order: -1; }
    .lesson-sidebar .sidebar-card:nth-child(3) { order: 3; }
    .lesson-navigation { flex-direction: column; }
    .breadcrumb { flex-wrap: nowrap; overflow-x: auto; white-space: nowrap; padding-bottom: var(--space-xs); }
    .glossary-controls { margin-bottom: var(--space-lg); }
    .search-field { grid-column: 1 / -1; }
    .search-field input { min-height: 48px; }
    .search-field .btn-search { padding: 0.5rem 0.75rem; min-height: 48px; font-size: 0.9375rem; }
    .filter-row { grid-template-columns: 1fr; }
    .filter-group select { min-height: 48px; }
    .alpha-bar { gap: var(--space-xs); }
    .alpha-item { min-width: 32px; height: 32px; font-size: 0.8125rem; }
    .pagination-list { gap: var(--space-xs); }
    .pagination-btn { min-width: 36px; height: 36px; font-size: 0.875rem; }
    .flashcard-filters .filter-row { grid-template-columns: 1fr; }
    .flashcard-controls { gap: var(--space-md); }
    .fc-stats { justify-content: space-between; }
    .active-filters { gap: var(--space-xs); }
    .filter-tag { font-size: 0.75rem; }
    .quiz-step-actions .btn { flex: 1; padding-inline: .5rem; white-space: normal; }
    .choice-label { align-items: flex-start; padding: var(--space-md); }
    .flashcard { height: 180px; }
    .flashcard-actions { display: grid; grid-template-columns: 1fr; }
    .fc-stats { width: 100%; justify-content: space-between; gap: var(--space-sm); }
    .toast-container { left: var(--space-md); right: var(--space-md); bottom: calc(76px + var(--space-sm)); }
    .toast { width: 100%; }
    .profile-grid { gap: var(--space-md); }
}

@media (min-width: 768px) and (max-width: 1023px) {
    .main-nav { overflow-x: auto; }
    .nav-link { padding-inline: .65rem; font-size: .85rem; }
    .header-inner { gap: var(--space-md); }
    .header-register { display: none; }
    .lesson-sidebar { display: grid; grid-template-columns: repeat(2, 1fr); }
    .lesson-sidebar .sidebar-card:last-child { grid-column: 1 / -1; }
}

@media (min-width: 1280px) {
    .container { padding-inline: var(--space-xl); }
}

/* ===== Print Styles ===== */
/* Lesson action area (shown after last lesson) */
.lesson-action-area {
    margin-top: var(--space-xl);
    padding-top: var(--space-xl);
    border-top: 1px solid var(--color-border);
}

/* Module progress in sidebar */
.module-progress-info {
    margin-bottom: var(--space-xs);
}

.module-progress-count {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-text);
    display: block;
    margin-bottom: var(--space-xs);
}

.module-progress-pct {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    display: block;
    margin-top: var(--space-xs);
}

/* Module progress summary on module page */
.module-progress-summary {
    margin-top: var(--space-lg);
    background: white;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-md);
}

.module-progress-label {
    display: block;
    font-size: 0.9rem;
    font-weight: 700;
    margin-bottom: 0.4rem;
}

.module-progress-pct {
    display: block;
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    margin-top: var(--space-xs);
}

@media print {
    .site-header, .site-footer, .lesson-sidebar, .lesson-navigation, .breadcrumb { display: none; }
    .lesson-content { font-size: 12pt; }
}

/* ===== Reduced Motion ===== */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}

/* ===== High Contrast ===== */
@media (prefers-contrast: high) {
    :root {
        --color-border: #555;
        --color-text-muted: #666;
    }
    .btn { border-width: 3px; }
    .choice-label { border-width: 3px; }
}

/* ===== Overhaul: Streak callout ===== */
.streak-callout {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md) var(--space-lg);
    background: linear-gradient(135deg, var(--color-warning-bg), var(--color-warning));
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-lg);
}

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

.streak-callout p {
    margin: 0;
    font-weight: 700;
    color: var(--color-text);
}

.streak-keep-going {
    margin-left: auto;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-primary-dark);
}

/* ===== Overhaul: Learning roadmap / path cards on dashboard ===== */
.roadmap-section {
    margin-bottom: var(--space-xl);
}

.path-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--space-md);
    margin-top: var(--space-md);
}

.path-card-dashboard {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.path-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--space-sm);
}

.path-card-header h3 {
    font-size: 1rem;
    margin: 0;
}

.path-card-progress {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.path-card-meta {
    font-size: 0.8125rem;
    color: var(--color-text-secondary);
}

.path-card-complete {
    display: inline-block;
    font-size: 0.875rem;
    color: var(--color-success);
    font-weight: 600;
}

/* ===== Overhaul: Next badge card ===== */
.next-badge-section {
    margin-bottom: var(--space-xl);
}

.next-badge-card {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
    padding: var(--space-lg);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
}

.next-badge-icon {
    font-size: 2.5rem;
    opacity: 0.5;
    filter: grayscale(1);
}

.next-badge-info {
    flex: 1;
}

.next-badge-info h3 {
    margin: 0 0 var(--space-xs) 0;
    font-size: 1rem;
}

.next-badge-info p {
    margin: 0 0 var(--space-sm) 0;
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

.next-badge-meta {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    margin-top: var(--space-xs);
    display: block;
}

/* ===== Overhaul: Notes section ===== */
.notes-section,
.bookmarks-section {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
}

.notes-section h2,
.bookmarks-section h2 {
    font-size: 1rem;
    margin-bottom: var(--space-md);
}

.notes-list,
.bookmarks-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.note-item,
.bookmark-item {
    padding: var(--space-sm) 0;
    border-bottom: 1px solid var(--color-border-light);
}

.note-item:last-child,
.bookmark-item:last-child {
    border-bottom: none;
}

.note-item a,
.bookmark-item a {
    font-weight: 600;
    font-size: 0.9rem;
}

.note-preview {
    font-size: 0.8125rem;
    color: var(--color-text-secondary);
    margin: var(--space-xs) 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.note-item time,
.bookmark-item time {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

/* ===== Overhaul: Lesson callouts (quiz, flashcard, glossary prompts) ===== */
.lesson-callout {
    padding: var(--space-lg);
    border-radius: var(--radius-lg);
    margin-top: var(--space-lg);
}

.lesson-callout h3 {
    font-size: 1rem;
    margin: 0 0 var(--space-sm) 0;
}

.lesson-callout p {
    margin: 0 0 var(--space-md) 0;
    font-size: 0.9rem;
}

/* Quiz prompt */
.quiz-prompt {
    background: var(--color-info-bg);
    border-left: 4px solid var(--color-info);
}

/* Flashcard prompt */
.flashcard-prompt {
    background: var(--color-accent-light);
    border-left: 4px solid var(--color-accent);
}

/* Glossary prompt */
.glossary-prompt {
    background: var(--color-primary-bg);
    border-left: 4px solid var(--color-primary);
}

.glossary-prompt-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    margin: var(--space-sm) 0;
    padding: 0;
    list-style: none;
}

.glossary-prompt-item {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

/* ===== Overhaul: Inline glossary terms ===== */
.glossary-term-inline {
    cursor: pointer;
    text-decoration: underline;
    text-decoration-style: dotted;
    text-underline-offset: 3px;
    color: var(--color-primary);
    font-weight: 500;
    position: relative;
}

.glossary-term-inline:hover {
    color: var(--color-primary-dark);
    background: var(--color-primary-bg);
}

/* Glossary popover */
.glossary-popover {
    position: fixed;
    z-index: 1000;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-md);
    max-width: 320px;
    box-shadow: var(--shadow-xl);
    display: none;
}

.glossary-popover.active {
    display: block;
}

.glossary-popover-term {
    font-weight: 700;
    font-size: 1rem;
    margin-bottom: var(--space-xs);
}

.glossary-popover-def {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    line-height: 1.5;
}

.glossary-popover-close {
    position: absolute;
    top: var(--space-xs);
    right: var(--space-sm);
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.2rem;
    color: var(--color-text-muted);
    padding: 0;
    line-height: 1;
}

/* ===== Overhaul: Sidebar glossary list ===== */
.sidebar-glossary-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
    padding: 0;
    list-style: none;
}

.sidebar-glossary-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-sm);
    padding: var(--space-xs) 0;
}

/* ===== Overhaul: Module time estimate ===== */
.module-time-estimate {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    margin-top: var(--space-xs);
}

/* ===== Overhaul: Module resources ===== */
.module-resources {
    margin-bottom: var(--space-lg);
}

.module-resources h2 {
    font-size: 1.1rem;
    margin-bottom: var(--space-md);
}

.module-resource-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.module-resource-card {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    transition: border-color var(--transition-fast);
}

.module-resource-card:hover {
    border-color: var(--color-primary);
}

.resource-icon {
    font-size: 1.25rem;
}

.module-resource-card strong {
    display: block;
    font-size: 0.9rem;
}

.module-resource-card .difficulty-badge {
    font-size: 0.75rem;
}

/* ===== Overhaul: Path progress bar on subject page ===== */
.path-progress-bar {
    margin-top: var(--space-sm);
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.path-progress-text {
    font-size: 0.8125rem;
    color: var(--color-text-secondary);
}

/* ===== Overhaul: Next badge card on profile ===== */
.next-badge-card-profile {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
}

.next-badge-card-profile h3 {
    font-size: 1rem;
    margin-bottom: var(--space-md);
}

.next-badge-card-profile .next-badge-card {
    background: none;
    border: none;
    padding: 0;
}

/* ===== Overhaul: Section heading row ===== */
.section-heading-row {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: var(--space-md);
}

.section-heading-row h2 {
    margin: 0;
    font-size: 1.1rem;
}

.section-heading-row p {
    margin: 0;
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

/* ===== Overhaul: Responsive adjustments ===== */
@media (max-width: 640px) {
    .streak-callout {
        flex-wrap: wrap;
    }

    .streak-keep-going {
        margin-left: 0;
        width: 100%;
        text-align: center;
        margin-top: var(--space-xs);
    }

    .next-badge-card {
        flex-direction: column;
        text-align: center;
    }

    .next-badge-icon {
        font-size: 2rem;
    }

    .path-cards {
        grid-template-columns: 1fr;
    }

    .notes-list,
    .bookmarks-list {
        gap: var(--space-sm);
    }

    .section-heading-row {
        flex-direction: column;
        gap: var(--space-xs);
    }
}