* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #60A5FA;
    --primary-dark: #3B82F6;
    --secondary-color: #FB7185;
    --accent-color: #5EEAD4;
    --success-color: #4ADE80;
    --warning-color: #FBBF24;
    --error-color: #F87171;
    --bg-color: #F8FAFC;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #475569;
    --border-color: #E2E8F0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.2), 0 2px 4px -1px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.25), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
}

body {
    font-family: 'Nunito', sans-serif;
    background: var(--user-bg, linear-gradient(135deg, #1E3A5F 0%, #2D4A6B 50%, #1E4A6B 100%));
    min-height: 100vh;
    color: var(--text-primary);
    line-height: 1.6;
}

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

.navbar {
    background: var(--card-bg);
    box-shadow: var(--shadow);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary-color);
}

.nav-brand i {
    font-size: 2rem;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 600;
    transition: color 0.3s;
}

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

.main-content {
    min-height: calc(100vh - 200px);
    padding: 2rem 0;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Hero Section */
.hero-section {
    text-align: center;
    padding: 4rem 2rem;
    color: white;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 3rem;
    opacity: 0.95;
}

.hero-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin: 3rem 0;
    max-width: 1000px;
    margin-left: auto;
    margin-right: auto;
}

.feature-card {
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: white;
}

.feature-card i {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: #FBBF24;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: white;
}

.feature-card p {
    color: rgba(255, 255, 255, 0.95);
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-family: 'Nunito', sans-serif;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px) scale(1.02);
    box-shadow: var(--shadow-lg);
}

/* Shop + Arcade */
.shop-hero, .arcade-hero {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
}

.shop-hero h1, .arcade-hero h1 {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 2rem;
}

.shop-grid, .arcade-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 1.25rem;
}

.shop-card, .game-card {
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 14px;
    padding: 1.25rem;
    box-shadow: var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
    position: relative;
}

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

.shop-card h3, .game-card h3 {
    margin-bottom: 0.35rem;
}

.shop-meta {
    display: flex;
    gap: 0.5rem;
    align-items: center;
    flex-wrap: wrap;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-weight: 700;
}

.flair-preview {
    width: 100%;
    height: 120px;
    border-radius: 12px;
    margin-bottom: 0.75rem;
    border: 2px solid rgba(0, 0, 0, 0.05);
    box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.25);
}

.shop-actions {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-top: 0.75rem;
}

.badge-owned {
    background: var(--success-color);
    color: #0f172a;
    padding: 0.25rem 0.65rem;
    border-radius: 999px;
    font-weight: 700;
    font-size: 0.85rem;
}

.badge-locked {
    background: var(--error-color);
    color: #fff;
    padding: 0.25rem 0.65rem;
    border-radius: 999px;
    font-weight: 700;
    font-size: 0.85rem;
}

.lock-badge {
    position: absolute;
    top: 12px;
    right: 12px;
    background: var(--error-color);
    color: #fff;
    padding: 0.35rem 0.6rem;
    border-radius: 10px;
    font-size: 0.85rem;
    font-weight: 700;
    box-shadow: var(--shadow);
}

.game-stat {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Mini game screens */
.minigame-shell {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 1.5rem;
    box-shadow: var(--shadow-lg);
    max-width: 900px;
    margin: 0 auto;
}

.reaction-stage {
    height: 220px;
    border-radius: 12px;
    display: grid;
    place-items: center;
    color: #fff;
    font-size: 1.3rem;
    font-weight: 800;
    transition: background 0.2s, filter 0.2s;
}

.memory-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 0.75rem;
}

.memory-card {
    background: #0f172a;
    color: #fff;
    border-radius: 12px;
    padding: 1rem;
    text-align: center;
    cursor: pointer;
    min-height: 110px;
    display: grid;
    place-items: center;
    border: 2px solid #334155;
    transition: transform 0.15s, border 0.15s;
}

.memory-card.revealed {
    background: #10b981;
    color: #0f172a;
    border-color: #059669;
    transform: scale(1.02);
}

.memory-card.matched {
    background: #c7d2fe;
    color: #1e293b;
    border-color: #818cf8;
}

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

.btn-secondary:hover {
    background: var(--bg-color);
    transform: translateY(-2px) scale(1.02);
    border: 2px solid var(--primary-color);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.1rem;
}

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
}

.btn-block {
    width: 100%;
    justify-content: center;
}

/* Auth Pages */
.auth-container {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 3rem 2rem;
    min-height: calc(100vh - 200px);
}

.auth-card {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 3rem;
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 450px;
}

.auth-header {
    text-align: center;
    margin-bottom: 2rem;
}

.auth-header i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.auth-header h2 {
    font-size: 2rem;
    color: var(--text-primary);
}

.auth-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-weight: 600;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.form-group input,
.form-group select {
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-family: 'Nunito', sans-serif;
    transition: border-color 0.3s;
}

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

.auth-links {
    text-align: center;
    margin-top: 1rem;
}

.auth-links a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}

.message {
    padding: 1rem;
    border-radius: 8px;
    text-align: center;
    font-weight: 600;
}

.message.success {
    background: #D1FAE5;
    color: #065f46;
    border-left: 4px solid var(--success-color);
}

.message.error {
    background: #FEE2E2;
    color: #991b1b;
    border-left: 4px solid var(--error-color);
}

/* Dashboard */
.dashboard-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.dashboard-header {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
}

.dashboard-header h1 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 1rem;
}

.stats-bar {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.stat-card {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
    padding: 1.5rem;
    border-radius: 12px;
    display: flex;
    align-items: center;
    gap: 1rem;
    box-shadow: var(--shadow);
    transition: transform 0.3s;
}

.stat-card:hover {
    transform: translateY(-4px) scale(1.02);
}

.stat-card i {
    font-size: 2.5rem;
}

.stat-value {
    font-size: 2rem;
    font-weight: 800;
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.9;
}

.dashboard-actions {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.flair-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    color: #0f172a;
    font-size: 0.9rem;
    font-weight: 700;
    box-shadow: var(--shadow);
    text-transform: capitalize;
}

/* Lessons */
.lessons-section {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
}

.lessons-section h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.lessons-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.lesson-card {
    background: var(--bg-color);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    transition: all 0.3s;
}

.lesson-card:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
    border-width: 3px;
}

.lesson-card.completed {
    border-color: var(--success-color);
    background: linear-gradient(135deg, #D1FAE5 0%, #ECFDF5 100%);
}

.lesson-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 1rem;
}

.lesson-header h3 {
    font-size: 1.3rem;
    color: var(--text-primary);
}

.lesson-badge {
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

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

.lesson-badge.pending {
    background: var(--warning-color);
    color: white;
}

.lesson-description {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.lesson-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.lesson-points {
    color: #F97316;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

/* Badges */
.badges-section {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
}

.badges-section h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.badges-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.badge-item {
    padding: 1rem 1.5rem;
    border-radius: 12px;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    box-shadow: var(--shadow);
    /* Default to unearned style */
    background: linear-gradient(135deg, #9CA3AF, #6B7280);
    color: #E5E7EB;
    opacity: 0.7;
    cursor: default;
}

.badge-item.earned {
    background: linear-gradient(135deg, #FCD34D, #FBBF24) !important;
    color: #78350F !important;
    opacity: 1 !important;
    transition: transform 0.3s;
}

.badge-item.earned:hover {
    transform: scale(1.05) rotate(2deg);
}

.badge-item.unearned {
    background: linear-gradient(135deg, #9CA3AF, #6B7280) !important;
    color: #E5E7EB !important;
    opacity: 0.7 !important;
    cursor: default;
}

.badge-item i {
    font-size: 1.5rem;
}

/* Available Badges Section */
.available-badges-section {
    background: var(--card-bg) !important;
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
    display: block;
}

.available-badges-section h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.section-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 1rem;
    line-height: 1.6;
}

.badges-info-grid {
    display: grid !important;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)) !important;
    gap: 1.5rem;
}

.badge-info-card {
    background: var(--bg-color);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    transition: all 0.3s;
    position: relative;
}

.badge-info-card.earned {
    border-color: #FBBF24;
    background: linear-gradient(135deg, rgba(252, 211, 77, 0.1), rgba(251, 191, 36, 0.1));
}

.badge-info-card.unearned {
    opacity: 0.9;
}

.badge-info-card:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
    border-width: 3px;
}

.badge-info-card.earned:hover {
    border-color: #FBBF24;
}

.badge-info-header {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
}

.badge-info-icon {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    font-size: 1.5rem;
}

.badge-info-card.earned .badge-info-icon {
    background: linear-gradient(135deg, #FCD34D, #FBBF24);
    color: #78350F;
}

.badge-info-card.unearned .badge-info-icon {
    background: linear-gradient(135deg, #9CA3AF, #6B7280);
    color: #E5E7EB;
}

.badge-info-content {
    flex: 1;
    min-width: 0;
}

.badge-info-content h3 {
    font-size: 1.2rem;
    margin: 0 0 0.5rem 0;
    color: var(--text-primary);
    font-weight: 600;
}

.badge-info-card.earned .badge-info-content h3 {
    color: #78350F;
}

.badge-info-content p {
    margin: 0;
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}

.badge-info-status {
    position: absolute;
    top: 1rem;
    right: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #10B981;
    font-size: 0.85rem;
    font-weight: 600;
    background: rgba(16, 185, 129, 0.1);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
}

.badge-info-status i {
    font-size: 1rem;
}

/* Lesson View */
.lesson-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 2rem;
}

.lesson-header {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    margin-bottom: 1rem;
}

.back-link:hover {
    text-decoration: underline;
}

.lesson-header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.lesson-meta {
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.content-section {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
}

.markdown-content {
    line-height: 1.8;
}

.markdown-content h1,
.markdown-content h2,
.markdown-content h3 {
    margin: 1.5rem 0 1rem 0;
    color: var(--text-primary);
}

.markdown-content code {
    background: var(--bg-color);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
}

.markdown-content pre {
    background: #1e293b;
    color: #e2e8f0;
    padding: 1rem;
    border-radius: 8px;
    overflow-x: auto;
    margin: 1rem 0;
}

.markdown-content pre code {
    background: transparent;
    padding: 0;
    color: inherit;
}

.markdown-content code {
    background: var(--bg-color);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    color: var(--primary-color);
}

.exercises-section {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: var(--shadow);
}

.exercises-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.exercise-item {
    background: var(--bg-color);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    transition: all 0.3s;
}

.exercise-item:hover {
    border-color: var(--primary-color);
    transform: translateX(4px) scale(1.01);
    border-width: 3px;
}

.exercise-item.completed {
    border-color: var(--success-color);
    background: linear-gradient(135deg, #D1FAE5 0%, #ECFDF5 100%);
}

.exercise-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 0.5rem;
}

.exercise-header h3 {
    font-size: 1.2rem;
    color: var(--text-primary);
}

.exercise-badge {
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.exercise-badge.completed {
    background: var(--success-color);
    color: white;
}

.exercise-badge.pending {
    background: var(--border-color);
    color: var(--text-secondary);
}

.exercise-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1rem;
}

.exercise-meta {
    color: var(--text-secondary);
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.separator {
    margin: 0 0.5rem;
}

/* Exercise View */
.exercise-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.exercise-header {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
}

.exercise-header h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.exercise-description {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

.exercise-meta {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
    color: var(--text-secondary);
}

.completed-badge {
    color: var(--success-color);
    font-weight: 600;
}

.exercise-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 2rem;
}

.code-section {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.code-header h3 {
    font-size: 1.3rem;
    color: var(--text-primary);
}

.code-actions {
    display: flex;
    gap: 0.5rem;
}

.code-output {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 8px;
    min-height: 100px;
    background: var(--bg-color);
    font-family: 'Courier New', monospace;
}

.code-output.success {
    background: #D1FAE5;
    color: #065f46;
    border-left: 4px solid var(--success-color);
}

.code-output.error {
    background: #FEE2E2;
    color: #991b1b;
    border-left: 4px solid var(--error-color);
}

.code-output pre {
    margin: 0;
    white-space: pre-wrap;
}

.loading {
    text-align: center;
    padding: 2rem;
}

.success-message,
.error-message {
    padding: 1rem;
    border-radius: 8px;
    text-align: center;
}

.success-message {
    background: #D1FAE5;
    color: #065f46;
    border-left: 4px solid var(--success-color);
}

.error-message {
    background: #FEE2E2;
    color: #991b1b;
    border-left: 4px solid var(--error-color);
}

.instructions-section {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 1.5rem;
    box-shadow: var(--shadow);
    height: fit-content;
    max-height: calc(100vh - 200px);
    overflow-y: auto;
}

.instructions-section h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.instructions-content {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.exercise-task {
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border-color);
}

.exercise-task h4 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.exercise-task p {
    color: var(--text-secondary);
    line-height: 1.6;
}

.lesson-reference {
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border-color);
}

.lesson-reference h4 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.reference-note {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 1rem;
    font-style: italic;
}

.lesson-content-preview {
    background: var(--bg-color);
    border-radius: 8px;
    padding: 1rem;
    max-height: 400px;
    overflow-y: auto;
    border: 1px solid var(--border-color);
}

.lesson-content-preview h1,
.lesson-content-preview h2,
.lesson-content-preview h3 {
    font-size: 1rem;
    margin: 0.75rem 0 0.5rem 0;
    color: var(--text-primary);
}

.lesson-content-preview p {
    margin: 0.5rem 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.5;
}

.lesson-content-preview code {
    background: var(--card-bg);
    padding: 0.15rem 0.3rem;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.85rem;
    color: var(--primary-color);
}

.lesson-content-preview pre {
    background: #1e293b;
    color: #e2e8f0;
    padding: 0.75rem;
    border-radius: 6px;
    overflow-x: auto;
    margin: 0.75rem 0;
    font-size: 0.85rem;
}

.lesson-content-preview pre code {
    background: transparent;
    padding: 0;
    color: inherit;
}

.lesson-content-preview ul,
.lesson-content-preview ol {
    margin: 0.5rem 0;
    padding-left: 1.5rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.hint-box {
    background: linear-gradient(135deg, #EFF6FF 0%, #DBEAFE 100%);
    border-left: 4px solid var(--primary-color);
    padding: 1rem;
    border-radius: 8px;
    margin-top: 1rem;
}

.hint-box i {
    color: var(--primary-color);
    margin-right: 0.5rem;
}

/* Teacher Dashboard */
.students-section {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
}

.students-section h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.students-table {
    overflow-x: auto;
}

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

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

.students-table th {
    background: var(--bg-color);
    font-weight: 700;
    color: var(--text-primary);
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--border-color);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color), var(--secondary-color));
    transition: width 0.3s;
    box-shadow: 0 2px 4px rgba(96, 165, 250, 0.2);
}

.progress-text {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.points-badge {
    background: linear-gradient(135deg, #FCD34D, #FBBF24);
    color: #78350F;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    box-shadow: 0 2px 4px rgba(251, 191, 36, 0.25);
}

/* Student Detail */
.student-detail-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.student-header {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
}

.student-header h1 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.student-stats {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.progress-section {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: var(--shadow);
}

.progress-section h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.lesson-progress-card {
    background: var(--bg-color);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    border: 2px solid var(--border-color);
}

.lesson-progress-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.exercises-progress {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.exercise-progress-item {
    background: white;
    padding: 1rem;
    border-radius: 8px;
    border-left: 4px solid var(--border-color);
}

.exercise-progress-item.completed {
    border-left-color: var(--success-color);
    background: linear-gradient(135deg, #D1FAE5 0%, #ECFDF5 100%);
}

.exercise-info {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

/* Info Section */
.cta-section {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 3rem 2rem;
    color: white;
    text-align: center;
}

.cta-content {
    max-width: 800px;
    margin: 0 auto;
}

.cta-text {
    font-size: 1.5rem;
    font-weight: 600;
    line-height: 1.6;
    color: white;
    margin-bottom: 1rem;
}

.stat-highlight {
    font-size: 1.8rem;
    font-weight: 800;
    color: #FBBF24;
    text-shadow: 0 2px 4px rgba(251, 191, 36, 0.3);
    display: inline-block;
    padding: 0 0.25rem;
}

.cta-subtext {
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-top: 0.5rem;
}

.cta-subtext i {
    color: #4ADE80;
    font-size: 1.2rem;
}

.info-section {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 4rem 2rem;
    color: white;
}

.info-section h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.info-item {
    text-align: center;
    padding: 2rem;
}

.info-item i {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: #FBBF24;
    filter: drop-shadow(0 2px 4px rgba(251, 191, 36, 0.3));
}

.info-item h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

/* Footer */
.footer {
    background: var(--card-bg);
    text-align: center;
    padding: 2rem;
    margin-top: 3rem;
    color: var(--text-secondary);
}

/* Flash Messages */
.flash-messages {
    max-width: 1200px;
    margin: 1rem auto;
    padding: 0 2rem;
}

.flash-message {
    background: linear-gradient(135deg, var(--success-color), var(--accent-color));
    color: white;
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    text-align: center;
    font-weight: 600;
    box-shadow: var(--shadow);
}

/* Responsive */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .exercise-content {
        grid-template-columns: 1fr;
    }
    
    .nav-container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .stats-bar {
        grid-template-columns: 1fr;
    }
    
    .lessons-grid {
        grid-template-columns: 1fr;
    }
}