/* ============================================
   Padhle - Advanced Educational Platform
   High-Performance, Multilingual, Gamified
   ============================================ */

:root {
    /* Core Colors - Indigo Ink Palette */
    --primary-900: #0D0221;
    --primary-800: #1B0A3C;
    --primary-700: #3D1E7C;
    --primary-600: #5B21B6;
    --primary-500: #7B68EE;
    --primary-400: #9F7AEA;
    --primary-300: #B8A9D9;
    --primary-200: #D8D0E8;
    --primary-100: #E8E0F0;
    
    /* Accent Colors */
    --accent-gold: #FBBF24;
    --accent-green: #4ADE80;
    --accent-red: #EF4444;
    --accent-blue: #60A5FA;
    --accent-orange: #FB923C;
    
    /* Semantic Colors */
    --bg-primary: var(--primary-900);
    --bg-secondary: var(--primary-800);
    --bg-tertiary: var(--primary-700);
    --text-primary: #FFFFFF;
    --text-secondary: var(--primary-300);
    --text-muted: var(--primary-200);
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--primary-500) 0%, var(--primary-400) 100%);
    --gradient-gold: linear-gradient(135deg, var(--accent-gold) 0%, #F59E0B 100%);
    --gradient-success: linear-gradient(135deg, var(--accent-green) 0%, #22C55E 100%);
    --gradient-hero: linear-gradient(135deg, var(--primary-800) 0%, var(--primary-700) 50%, var(--primary-600) 100%);
    
    /* Typography */
    --font-primary: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-hindi: 'Noto Sans Devanagari', sans-serif;
    
    /* Spacing Scale */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(123, 104, 238, 0.4);
    --shadow-gold: 0 0 30px rgba(251, 191, 36, 0.3);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;
    
    /* Z-Index Scale */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-modal: 300;
    --z-tooltip: 400;
    --z-toast: 500;
}

/* ============================================
   Reset & Base Styles
   ============================================ */

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-primary);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

/* ============================================
   Loading Screen
   ============================================ */

.loading-screen {
    position: fixed;
    inset: 0;
    background: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.loading-content {
    text-align: center;
}

.loading-logo {
    font-size: 5rem;
    animation: bounce 1s ease infinite;
}

.loading-text {
    font-size: 2.5rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-top: var(--space-4);
}

.loading-bar {
    width: 200px;
    height: 4px;
    background: var(--primary-700);
    border-radius: var(--radius-full);
    margin: var(--space-6) auto;
    overflow: hidden;
}

.loading-progress {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    animation: loading 2s ease-in-out infinite;
}

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

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

@keyframes loading {
    0% { width: 0%; margin-left: 0; }
    50% { width: 100%; margin-left: 0; }
    100% { width: 0%; margin-left: 100%; }
}

/* ============================================
   App Container
   ============================================ */

.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ============================================
   Navigation
   ============================================ */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 70px;
    background: rgba(13, 2, 33, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(123, 104, 238, 0.2);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--space-6);
    z-index: var(--z-sticky);
}

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

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

.brand-text {
    font-size: 1.5rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.beta-badge {
    font-size: 0.65rem;
    padding: 2px 6px;
    background: var(--accent-gold);
    color: var(--primary-900);
    border-radius: var(--radius-sm);
    font-weight: 700;
}

.nav-links {
    display: flex;
    gap: var(--space-2);
}

.nav-link {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9rem;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-primary);
    background: rgba(123, 104, 238, 0.2);
}

.nav-link i {
    font-size: 1rem;
}

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

.lang-toggle {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    background: rgba(123, 104, 238, 0.2);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.85rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.lang-toggle:hover {
    background: rgba(123, 104, 238, 0.3);
}

.emergency-btn {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    background: linear-gradient(135deg, var(--accent-gold), #F59E0B);
    border: none;
    border-radius: var(--radius-md);
    color: var(--primary-900);
    font-weight: 600;
    font-size: 0.85rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    animation: pulse-gold 2s ease-in-out infinite;
}

.emergency-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-gold);
}

@keyframes pulse-gold {
    0%, 100% { box-shadow: 0 0 0 0 rgba(251, 191, 36, 0.4); }
    50% { box-shadow: 0 0 0 8px rgba(251, 191, 36, 0); }
}

.user-stats {
    display: flex;
    gap: var(--space-4);
}

.stat-item {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    padding: var(--space-1) var(--space-3);
    background: rgba(123, 104, 238, 0.15);
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    font-weight: 600;
}

.stat-item i {
    color: var(--accent-gold);
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.25rem;
    cursor: pointer;
}

/* ============================================
   AI Avatar
   ============================================ */

.ai-avatar-container {
    position: fixed;
    bottom: 100px;
    right: 30px;
    z-index: var(--z-dropdown);
    cursor: pointer;
}

.ai-avatar {
    width: 70px;
    height: 70px;
    position: relative;
}

.avatar-face {
    width: 100%;
    height: 100%;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
    z-index: 2;
    box-shadow: var(--shadow-glow);
    animation: float 3s ease-in-out infinite;
}

.avatar-eyes {
    display: flex;
    gap: 12px;
    margin-bottom: 8px;
}

.eye {
    width: 12px;
    height: 12px;
    background: white;
    border-radius: 50%;
    animation: blink 4s ease-in-out infinite;
}

.avatar-mouth {
    width: 20px;
    height: 10px;
    border-bottom: 3px solid white;
    border-radius: 0 0 20px 20px;
}

.avatar-glow {
    position: absolute;
    inset: -10px;
    background: var(--gradient-primary);
    border-radius: 50%;
    opacity: 0.3;
    filter: blur(20px);
    animation: pulse-glow 2s ease-in-out infinite;
}

.avatar-tooltip {
    position: absolute;
    right: 90px;
    top: 50%;
    transform: translateY(-50%);
    background: var(--primary-700);
    padding: var(--space-2) var(--space-4);
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    white-space: nowrap;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
}

.ai-avatar-container:hover .avatar-tooltip {
    opacity: 1;
    visibility: visible;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

@keyframes blink {
    0%, 45%, 55%, 100% { transform: scaleY(1); }
    50% { transform: scaleY(0.1); }
}

@keyframes pulse-glow {
    0%, 100% { transform: scale(1); opacity: 0.3; }
    50% { transform: scale(1.1); opacity: 0.5; }
}

/* ============================================
   Main Content
   ============================================ */

.main-content {
    flex: 1;
    padding-top: 70px;
}

.section {
    display: none;
    padding: var(--space-8);
    max-width: 1400px;
    margin: 0 auto;
}

.section.active {
    display: block;
    animation: fadeIn 0.4s ease;
}

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

/* ============================================
   Hero Section
   ============================================ */

.hero-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-12);
    align-items: center;
    min-height: calc(100vh - 150px);
    padding: var(--space-8) 0;
}

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

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    background: rgba(123, 104, 238, 0.2);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    color: var(--primary-400);
    margin-bottom: var(--space-6);
}

.hero-badge i {
    color: var(--accent-gold);
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--space-6);
}

.title-line {
    display: block;
}

.title-line.gradient {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-8);
    line-height: 1.7;
}

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

.hero-visual {
    position: relative;
    height: 100%;
    min-height: 400px;
}

.floating-cards {
    position: absolute;
    inset: 0;
}

.float-card {
    position: absolute;
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-4) var(--space-5);
    background: rgba(123, 104, 238, 0.15);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-lg);
    backdrop-filter: blur(10px);
    animation: float-card 6s ease-in-out infinite;
    animation-delay: var(--delay);
}

.float-card:nth-child(1) { top: 10%; left: 0; }
.float-card:nth-child(2) { top: 30%; right: 0; }
.float-card:nth-child(3) { bottom: 30%; left: 10%; }
.float-card:nth-child(4) { bottom: 10%; right: 10%; }

.float-card i {
    font-size: 1.5rem;
    color: var(--primary-400);
}

.float-card span {
    font-weight: 600;
    font-size: 0.95rem;
}

@keyframes float-card {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-15px); }
}

.hero-illustration {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0.3;
    pointer-events: none;
}

.hero-svg {
    width: 80%;
    height: auto;
}

/* ============================================
   Buttons
   ============================================ */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    border-radius: var(--radius-md);
    font-family: var(--font-primary);
    font-weight: 600;
    font-size: 0.95rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    border: none;
    outline: none;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

.btn-primary.btn-glow {
    animation: btn-glow 2s ease-in-out infinite;
}

@keyframes btn-glow {
    0%, 100% { box-shadow: 0 4px 12px rgba(123, 104, 238, 0.4); }
    50% { box-shadow: 0 4px 24px rgba(123, 104, 238, 0.6); }
}

.btn-secondary {
    background: rgba(123, 104, 238, 0.2);
    color: var(--text-primary);
    border: 1px solid rgba(123, 104, 238, 0.3);
}

.btn-secondary:hover {
    background: rgba(123, 104, 238, 0.3);
}

.btn-danger {
    background: rgba(239, 68, 68, 0.2);
    color: var(--accent-red);
    border: 1px solid var(--accent-red);
}

.btn-danger:hover {
    background: var(--accent-red);
    color: white;
}

.btn-large {
    padding: var(--space-4) var(--space-8);
    font-size: 1.1rem;
}

.btn-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(123, 104, 238, 0.2);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-icon:hover {
    background: rgba(123, 104, 238, 0.3);
}

.btn-back {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 0.95rem;
    cursor: pointer;
    transition: color var(--transition-fast);
}

.btn-back:hover {
    color: var(--text-primary);
}

/* ============================================
   Quick Stats
   ============================================ */

.quick-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-6);
    margin: var(--space-12) 0;
}

.stat-card {
    background: rgba(123, 104, 238, 0.1);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--space-6);
    text-align: center;
    transition: all var(--transition-base);
}

.stat-card:hover {
    transform: translateY(-4px);
    border-color: var(--primary-500);
    box-shadow: var(--shadow-md);
}

.stat-icon {
    width: 50px;
    height: 50px;
    margin: 0 auto var(--space-4);
    background: var(--gradient-primary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.stat-value {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary-400);
    margin-bottom: var(--space-1);
}

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

/* ============================================
   Section Headings
   ============================================ */

.section-heading {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--space-6);
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

/* ============================================
   Continue Section
   ============================================ */

.continue-section {
    margin: var(--space-12) 0;
}

.continue-card {
    background: linear-gradient(135deg, rgba(123, 104, 238, 0.15), rgba(61, 30, 124, 0.3));
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-xl);
    padding: var(--space-6);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-6);
}

.continue-subject {
    display: inline-block;
    padding: var(--space-1) var(--space-3);
    background: var(--accent-gold);
    color: var(--primary-900);
    border-radius: var(--radius-full);
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: var(--space-2);
}

.continue-chapter {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--space-4);
}

.continue-progress {
    display: flex;
    align-items: center;
    gap: var(--space-4);
}

.progress-bar {
    width: 200px;
    height: 6px;
    background: rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    transition: width var(--transition-slow);
}

.progress-text {
    font-size: 0.85rem;
    color: var(--text-secondary);
    min-width: 100px;
}

/* ============================================
   Subjects Grid
   ============================================ */

.subjects-preview {
    margin: var(--space-12) 0;
}

.subjects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-6);
}

.subject-card {
    background: rgba(123, 104, 238, 0.1);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-xl);
    padding: var(--space-6);
    cursor: pointer;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.subject-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gradient-primary);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.subject-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary-500);
    box-shadow: var(--shadow-lg);
}

.subject-card:hover::before {
    opacity: 0.1;
}

.subject-card > * {
    position: relative;
    z-index: 1;
}

.subject-icon {
    width: 60px;
    height: 60px;
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    margin-bottom: var(--space-4);
}

.subject-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-2);
}

.subject-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: var(--space-4);
}

.chapter-count {
    display: inline-flex;
    align-items: center;
    gap: var(--space-1);
    padding: var(--space-1) var(--space-3);
    background: rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-full);
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--primary-400);
}

/* ============================================
   Features Section
   ============================================ */

.features-section {
    margin: var(--space-12) 0;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-6);
}

.feature-card {
    background: rgba(123, 104, 238, 0.1);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-xl);
    padding: var(--space-6);
    text-align: center;
    transition: all var(--transition-base);
}

.feature-card:hover {
    transform: translateY(-4px);
    border-color: var(--primary-500);
}

.feature-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto var(--space-4);
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.feature-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: var(--space-2);
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.6;
}

/* ============================================
   Section Header
   ============================================ */

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-8);
    flex-wrap: wrap;
    gap: var(--space-4);
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
}

.section-filters {
    display: flex;
    gap: var(--space-2);
}

.filter-btn {
    padding: var(--space-2) var(--space-4);
    background: rgba(123, 104, 238, 0.2);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-full);
    color: var(--text-secondary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--primary-500);
    color: white;
    border-color: var(--primary-500);
}

/* ============================================
   Chapter View
   ============================================ */

.chapter-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-6) 0;
    border-bottom: 1px solid rgba(123, 104, 238, 0.2);
    margin-bottom: var(--space-6);
    flex-wrap: wrap;
    gap: var(--space-4);
}

.chapter-meta {
    flex: 1;
}

.chapter-subject {
    display: inline-block;
    padding: var(--space-1) var(--space-3);
    background: var(--accent-gold);
    color: var(--primary-900);
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: var(--space-2);
}

.chapter-title {
    font-size: 1.75rem;
    font-weight: 700;
}

.chapter-actions {
    display: flex;
    gap: var(--space-2);
}

.chapter-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: var(--space-8);
}

/* Sidebar */

.chapter-sidebar {
    position: sticky;
    top: 90px;
    height: fit-content;
}

.sidebar-section {
    background: rgba(123, 104, 238, 0.1);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--space-5);
    margin-bottom: var(--space-4);
}

.sidebar-section h3 {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: var(--space-4);
    color: var(--primary-400);
}

.chapter-nav {
    list-style: none;
}

.chapter-nav li {
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.chapter-nav li::before {
    content: '•';
    color: var(--primary-500);
}

.chapter-nav li:hover,
.chapter-nav li.active {
    background: rgba(123, 104, 238, 0.2);
    color: var(--primary-400);
}

.quick-actions {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.quick-btn {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3);
    background: rgba(123, 104, 238, 0.15);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.quick-btn:hover {
    background: rgba(123, 104, 238, 0.25);
    border-color: var(--primary-500);
}

.quick-btn i {
    color: var(--primary-400);
}

/* Chapter Main Content */

.chapter-main {
    background: rgba(123, 104, 238, 0.05);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-xl);
    overflow: hidden;
}

.content-tabs {
    display: flex;
    border-bottom: 1px solid rgba(123, 104, 238, 0.2);
    background: rgba(123, 104, 238, 0.1);
}

.tab-btn {
    flex: 1;
    padding: var(--space-4);
    background: none;
    border: none;
    color: var(--text-secondary);
    font-family: var(--font-primary);
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
}

.tab-btn::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 3px;
    background: var(--gradient-primary);
    transition: width var(--transition-fast);
}

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

.tab-btn.active {
    color: var(--primary-400);
}

.tab-btn.active::after {
    width: 60%;
}

.tab-panel {
    display: none;
    padding: var(--space-6);
    min-height: 500px;
}

.tab-panel.active {
    display: block;
}

/* Learning Content */

.learning-content {
    margin-bottom: var(--space-8);
}

.learning-content h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-400);
    margin: var(--space-6) 0 var(--space-3);
}

.learning-content h3:first-child {
    margin-top: 0;
}

.learning-content p {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--space-4);
}

.learning-content ul,
.learning-content ol {
    margin-left: var(--space-5);
    margin-bottom: var(--space-4);
    color: var(--text-secondary);
}

.learning-content li {
    margin-bottom: var(--space-2);
}

.learning-content strong {
    color: var(--text-primary);
}

.diagram-container {
    background: rgba(123, 104, 238, 0.1);
    border-radius: var(--radius-lg);
    padding: var(--space-6);
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 300px;
}

.diagram-container svg {
    max-width: 100%;
    height: auto;
}

/* Practice Panel */

.practice-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-6);
}

.practice-stats {
    display: flex;
    gap: var(--space-6);
    font-weight: 600;
}

.mcq-container {
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
}

.mcq-question {
    background: rgba(123, 104, 238, 0.1);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--space-5);
}

.mcq-question h4 {
    font-size: 1.1rem;
    margin-bottom: var(--space-4);
    line-height: 1.6;
}

.mcq-options {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.mcq-option {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    background: rgba(123, 104, 238, 0.1);
    border: 2px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.mcq-option:hover {
    border-color: var(--primary-500);
    background: rgba(123, 104, 238, 0.2);
}

.mcq-option.selected {
    border-color: var(--primary-500);
    background: rgba(123, 104, 238, 0.3);
}

.mcq-option.correct {
    border-color: var(--accent-green);
    background: rgba(74, 222, 128, 0.2);
}

.mcq-option.incorrect {
    border-color: var(--accent-red);
    background: rgba(239, 68, 68, 0.2);
}

.option-letter {
    width: 32px;
    height: 32px;
    background: rgba(123, 104, 238, 0.3);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
}

/* Notes Panel */

.notes-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-6);
}

.handwritten-notes {
    background: #FFF8E7;
    border-radius: var(--radius-lg);
    padding: var(--space-6);
    color: #333;
    font-family: 'Comic Sans MS', cursive;
    line-height: 1.8;
    min-height: 400px;
}

/* Mind Map Panel */

.mindmap-controls {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    margin-bottom: var(--space-4);
}

.mindmap-canvas {
    background: rgba(123, 104, 238, 0.05);
    border-radius: var(--radius-lg);
    min-height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: auto;
}

/* ============================================
   Practice Section
   ============================================ */

.practice-options {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-6);
}

.practice-card {
    background: rgba(123, 104, 238, 0.1);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-xl);
    padding: var(--space-6);
    text-align: center;
    transition: all var(--transition-base);
    cursor: pointer;
}

.practice-card:hover {
    transform: translateY(-4px);
    border-color: var(--primary-500);
    box-shadow: var(--shadow-md);
}

.practice-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto var(--space-4);
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
}

.practice-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: var(--space-2);
}

.practice-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: var(--space-4);
}

/* ============================================
   Forum Section
   ============================================ */

.forum-layout {
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: var(--space-8);
}

.forum-sidebar {
    position: sticky;
    top: 90px;
    height: fit-content;
}

.forum-categories h3 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: var(--space-4);
}

.forum-categories ul {
    list-style: none;
}

.forum-categories li {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    color: var(--text-secondary);
}

.forum-categories li:hover,
.forum-categories li.active {
    background: rgba(123, 104, 238, 0.2);
    color: var(--text-primary);
}

.forum-categories li i {
    width: 20px;
    text-align: center;
}

.forum-filters {
    display: flex;
    gap: var(--space-2);
    margin-bottom: var(--space-6);
}

.filter-pill {
    padding: var(--space-2) var(--space-4);
    background: rgba(123, 104, 238, 0.2);
    border: none;
    border-radius: var(--radius-full);
    color: var(--text-secondary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.filter-pill:hover,
.filter-pill.active {
    background: var(--primary-500);
    color: white;
}

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

/* ============================================
   Profile Section
   ============================================ */

.profile-header {
    display: flex;
    align-items: center;
    gap: var(--space-6);
    padding: var(--space-8);
    background: linear-gradient(135deg, rgba(123, 104, 238, 0.2), rgba(61, 30, 124, 0.3));
    border-radius: var(--radius-xl);
    margin-bottom: var(--space-8);
}

.profile-avatar {
    position: relative;
}

.avatar-img {
    width: 100px;
    height: 100px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    box-shadow: var(--shadow-glow);
}

.avatar-edit {
    position: absolute;
    bottom: 0;
    right: 0;
    width: 32px;
    height: 32px;
    background: var(--primary-500);
    border: none;
    border-radius: 50%;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}

.profile-info h2 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--space-1);
}

.profile-level {
    color: var(--text-secondary);
    margin-bottom: var(--space-3);
}

.profile-badges {
    display: flex;
    gap: var(--space-2);
}

.badge {
    width: 36px;
    height: 36px;
    background: rgba(123, 104, 238, 0.3);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
    cursor: pointer;
    transition: transform var(--transition-fast);
}

.badge:hover {
    transform: scale(1.1);
}

.profile-stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-4);
    margin-bottom: var(--space-8);
}

.profile-stat {
    background: rgba(123, 104, 238, 0.1);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--space-5);
    text-align: center;
}

.profile-stat .stat-value {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary-400);
}

.profile-stat .stat-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: var(--space-1);
}

.profile-sections {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-6);
}

.profile-section {
    background: rgba(123, 104, 238, 0.1);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-xl);
    padding: var(--space-6);
}

.profile-section h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: var(--space-4);
}

/* ============================================
   Modals
   ============================================ */

.modal {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.8);
    z-index: var(--z-modal);
    align-items: center;
    justify-content: center;
    padding: var(--space-6);
    overflow-y: auto;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--bg-secondary);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-xl);
    width: 100%;
    max-width: 600px;
    max-height: 90vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    animation: modal-in 0.3s ease;
}

.modal-large {
    max-width: 800px;
}

.modal-fullscreen {
    padding: 0;
}

.modal-fullscreen .modal-content {
    max-width: 100%;
    max-height: 100vh;
    border-radius: 0;
    height: 100vh;
}

@keyframes modal-in {
    from {
        opacity: 0;
        transform: scale(0.95) translateY(20px);
    }
    to {
        opacity: 1;
        transform: scale(1) translateY(0);
    }
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-5);
    border-bottom: 1px solid rgba(123, 104, 238, 0.2);
}

.modal-header h3 {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    font-size: 1.25rem;
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    transition: color var(--transition-fast);
}

.modal-close:hover {
    color: var(--text-primary);
}

.modal-body {
    flex: 1;
    padding: var(--space-5);
    overflow-y: auto;
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: var(--space-3);
    padding: var(--space-5);
    border-top: 1px solid rgba(123, 104, 238, 0.2);
}

/* Doubt Modal */

.language-selector {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    margin-bottom: var(--space-4);
    flex-wrap: wrap;
}

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

.lang-btn {
    padding: var(--space-2) var(--space-4);
    background: rgba(123, 104, 238, 0.2);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-full);
    color: var(--text-secondary);
    font-size: 0.85rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.lang-btn:hover,
.lang-btn.active {
    background: var(--primary-500);
    color: white;
    border-color: var(--primary-500);
}

.doubt-input-container {
    position: relative;
    margin-bottom: var(--space-4);
}

.doubt-input-container textarea {
    width: 100%;
    min-height: 120px;
    background: rgba(123, 104, 238, 0.1);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-lg);
    padding: var(--space-4);
    padding-right: 100px;
    color: var(--text-primary);
    font-family: var(--font-primary);
    font-size: 1rem;
    resize: vertical;
    transition: border-color var(--transition-fast);
}

.doubt-input-container textarea:focus {
    outline: none;
    border-color: var(--primary-500);
}

.input-actions {
    position: absolute;
    right: var(--space-3);
    bottom: var(--space-3);
    display: flex;
    gap: var(--space-2);
}

.suggested-questions {
    margin-bottom: var(--space-4);
}

.suggested-questions span {
    display: block;
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-bottom: var(--space-2);
}

.suggestion-chips {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
}

.chip {
    padding: var(--space-2) var(--space-3);
    background: rgba(123, 104, 238, 0.2);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-full);
    color: var(--text-secondary);
    font-size: 0.85rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.chip:hover {
    background: var(--primary-500);
    color: white;
    border-color: var(--primary-500);
}

.doubt-response {
    background: rgba(123, 104, 238, 0.1);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--space-4);
    margin-top: var(--space-4);
}

.response-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-4);
}

.ai-indicator {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.ai-dot {
    width: 8px;
    height: 8px;
    background: var(--accent-green);
    border-radius: 50%;
    animation: pulse-dot 1.5s ease-in-out infinite;
}

@keyframes pulse-dot {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.response-actions {
    display: flex;
    gap: var(--space-2);
}

.response-content {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--space-4);
}

.response-content h4 {
    color: var(--primary-400);
    margin-bottom: var(--space-2);
}

.response-feedback {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding-top: var(--space-4);
    border-top: 1px solid rgba(123, 104, 238, 0.2);
}

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

.feedback-btn {
    width: 36px;
    height: 36px;
    background: rgba(123, 104, 238, 0.2);
    border: none;
    border-radius: 50%;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.feedback-btn:hover {
    background: var(--primary-500);
    color: white;
}

/* Emergency Modal */

.emergency-header {
    background: linear-gradient(135deg, rgba(251, 191, 36, 0.2), rgba(123, 104, 238, 0.2));
}

.emergency-title {
    display: flex;
    align-items: center;
    gap: var(--space-4);
}

.emergency-title i {
    font-size: 2rem;
    color: var(--accent-gold);
}

.emergency-title h3 {
    margin-bottom: var(--space-1);
}

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

.emergency-body {
    flex: 1;
    padding: var(--space-8);
}

.emergency-step {
    display: none;
}

.emergency-step.active {
    display: block;
    animation: fadeIn 0.4s ease;
}

.step-number {
    width: 40px;
    height: 40px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    margin-bottom: var(--space-4);
}

.step-content h4 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-6);
}

.time-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-4);
}

.time-card {
    background: rgba(123, 104, 238, 0.1);
    border: 2px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--space-6);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.time-card:hover,
.time-card.selected {
    border-color: var(--accent-gold);
    background: rgba(251, 191, 36, 0.1);
}

.time-card i {
    font-size: 2rem;
    color: var(--accent-gold);
    margin-bottom: var(--space-2);
    display: block;
}

.time-card span {
    font-weight: 600;
}

.form-select {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    background: rgba(123, 104, 238, 0.1);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-family: var(--font-primary);
    font-size: 1rem;
    margin-bottom: var(--space-4);
    cursor: pointer;
}

.form-select:focus {
    outline: none;
    border-color: var(--primary-500);
}

.chapter-checklist {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
    max-height: 300px;
    overflow-y: auto;
}

.checklist-item {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3);
    background: rgba(123, 104, 238, 0.1);
    border-radius: var(--radius-md);
    cursor: pointer;
}

.checklist-item input[type="checkbox"] {
    width: 20px;
    height: 20px;
    accent-color: var(--primary-500);
}

.exam-type-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-4);
}

.exam-type-card {
    background: rgba(123, 104, 238, 0.1);
    border: 2px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--space-6);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.exam-type-card:hover,
.exam-type-card.selected {
    border-color: var(--primary-500);
    background: rgba(123, 104, 238, 0.2);
}

.exam-type-card i {
    font-size: 2rem;
    color: var(--primary-400);
    margin-bottom: var(--space-2);
    display: block;
}

/* Emergency Plan */

.emergency-plan {
    height: 100%;
    display: flex;
    flex-direction: column;
}

.plan-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4) var(--space-6);
    background: rgba(123, 104, 238, 0.1);
    border-bottom: 1px solid rgba(123, 104, 238, 0.2);
}

.plan-timer {
    font-size: 2.5rem;
    font-weight: 800;
    font-family: monospace;
    color: var(--accent-gold);
}

.plan-progress {
    width: 200px;
    height: 8px;
    background: rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.plan-progress-bar {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    transition: width var(--transition-slow);
}

.plan-timeline {
    flex: 1;
    padding: var(--space-6);
    overflow-y: auto;
}

.plan-task {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    padding: var(--space-4);
    background: rgba(123, 104, 238, 0.1);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-3);
    transition: all var(--transition-fast);
}

.plan-task.active {
    border-color: var(--accent-gold);
    background: rgba(251, 191, 36, 0.1);
}

.plan-task.completed {
    opacity: 0.6;
}

.task-time {
    font-weight: 700;
    color: var(--primary-400);
    min-width: 60px;
}

.task-content {
    flex: 1;
}

.task-content h5 {
    font-weight: 600;
    margin-bottom: var(--space-1);
}

.task-content p {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.plan-current {
    padding: var(--space-6);
    background: rgba(123, 104, 238, 0.1);
    border-top: 1px solid rgba(123, 104, 238, 0.2);
}

.current-task-display {
    text-align: center;
    margin-bottom: var(--space-6);
}

.current-label {
    display: block;
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-bottom: var(--space-2);
}

.current-task-display h4 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--space-2);
}

.current-task-display p {
    color: var(--text-secondary);
}

.plan-controls {
    display: flex;
    justify-content: center;
    gap: var(--space-3);
}

.emergency-footer {
    justify-content: space-between;
}

/* ============================================
   Toast Notifications
   ============================================ */

.toast-container {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    z-index: var(--z-toast);
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.toast {
    background: var(--bg-secondary);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-lg);
    padding: var(--space-4) var(--space-6);
    display: flex;
    align-items: center;
    gap: var(--space-3);
    box-shadow: var(--shadow-lg);
    animation: toast-in 0.3s ease;
}

.toast.success {
    border-color: var(--accent-green);
}

.toast.error {
    border-color: var(--accent-red);
}

.toast.info {
    border-color: var(--accent-blue);
}

@keyframes toast-in {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ============================================
   Offline Indicator
   ============================================ */

.offline-indicator {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--accent-red);
    color: white;
    padding: var(--space-3);
    text-align: center;
    z-index: var(--z-toast);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 1200px) {
    .hero-section {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-content {
        max-width: 100%;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .hero-visual {
        display: none;
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .practice-options {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .navbar {
        padding: 0 var(--space-4);
    }
    
    .nav-links {
        display: none;
    }
    
    .menu-toggle {
        display: block;
    }
    
    .user-stats {
        display: none;
    }
    
    .emergency-btn span {
        display: none;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .quick-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .chapter-layout {
        grid-template-columns: 1fr;
    }
    
    .chapter-sidebar {
        position: static;
    }
    
    .practice-options {
        grid-template-columns: 1fr;
    }
    
    .forum-layout {
        grid-template-columns: 1fr;
    }
    
    .forum-sidebar {
        display: none;
    }
    
    .profile-stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .profile-sections {
        grid-template-columns: 1fr;
    }
    
    .time-grid,
    .exam-type-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .ai-avatar-container {
        bottom: 80px;
        right: 20px;
    }
    
    .ai-avatar {
        width: 55px;
        height: 55px;
    }
}

@media (max-width: 480px) {
    .section {
        padding: var(--space-4);
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .quick-stats {
        grid-template-columns: 1fr;
    }
    
    .stat-card {
        display: flex;
        align-items: center;
        text-align: left;
        gap: var(--space-4);
    }
    
    .stat-icon {
        margin: 0;
    }
    
    .continue-card {
        flex-direction: column;
        text-align: center;
    }
    
    .continue-progress {
        justify-content: center;
    }
    
    .content-tabs {
        flex-wrap: wrap;
    }
    
    .tab-btn {
        flex: 1 1 50%;
    }
}

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

.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;
}

.text-gradient {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.glow {
    box-shadow: var(--shadow-glow);
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--primary-800);
}

::-webkit-scrollbar-thumb {
    background: var(--primary-600);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-500);
}

/* Selection */
::selection {
    background: var(--primary-500);
    color: white;
}