/* ===================================
   EDUii - PROFESSIONAL EDUCATION PLATFORM
   Modern, SEO-Optimized Design
   =================================== */

/* CSS Variables */
:root {
    /* Primary Colors - Professional Education Theme */
    --primary-color: #6366F1;
    --primary-dark: #4F46E5;
    --primary-light: #818CF8;
    
    /* Secondary Colors */
    --secondary-color: #10B981;
    --accent-color: #F59E0B;
    --success-color: #10B981;
    --warning-color: #F59E0B;
    --error-color: #EF4444;
    
    /* Subject Colors */
    --physics-color: #8B5CF6;
    --chemistry-color: #EC4899;
    --math-color: #3B82F6;
    --biology-color: #10B981;
    
    /* Neutral Colors */
    --bg-primary: #FFFFFF;
    --bg-secondary: #F9FAFB;
    --bg-tertiary: #F3F4F6;
    --text-primary: #111827;
    --text-secondary: #6B7280;
    --text-light: #9CA3AF;
    --border-color: #E5E7EB;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #667EEA 0%, #764BA2 100%);
    --gradient-physics: linear-gradient(135deg, #8B5CF6 0%, #6366F1 100%);
    --gradient-chemistry: linear-gradient(135deg, #EC4899 0%, #F43F5E 100%);
    --gradient-math: linear-gradient(135deg, #3B82F6 0%, #2563EB 100%);
    --gradient-biology: linear-gradient(135deg, #10B981 0%, #059669 100%);
    
    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
    
    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;
    --spacing-3xl: 64px;
    --spacing-4xl: 96px;
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-2xl: 32px;
    --radius-full: 9999px;
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-heading: 'Space Grotesk', sans-serif;
    
    /* Transitions */
    --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===================================
   RESET & BASE STYLES
   =================================== */

* {
    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;
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
}

h1 { font-size: clamp(2.5rem, 5vw, 4.5rem); }
h2 { font-size: clamp(2rem, 4vw, 3.5rem); }
h3 { font-size: clamp(1.5rem, 3vw, 2.25rem); }
h4 { font-size: 1.5rem; }

p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

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

button {
    font-family: inherit;
    border: none;
    background: none;
    cursor: pointer;
    transition: all var(--transition-normal);
}

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

/* ===================================
   UTILITY CLASSES
   =================================== */

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.hidden {
    display: none !important;
}

.btn-block {
    width: 100%;
}

/* ===================================
   BUTTONS
   =================================== */

.btn-primary, .btn-secondary, .btn-white {
    padding: 14px 28px;
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 15px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    transition: all var(--transition-normal);
    white-space: nowrap;
}

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

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

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background: white;
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

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

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

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

.btn-large {
    padding: 18px 36px;
    font-size: 16px;
}

.btn-primary svg, .btn-secondary svg, .btn-white svg {
    width: 20px;
    height: 20px;
}

/* ===================================
   NAVIGATION
   =================================== */

.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

.nav-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-lg) 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-family: var(--font-heading);
    font-size: 28px;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo svg {
    width: 36px;
    height: 36px;
    stroke: var(--primary-color);
}

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

.nav-link {
    font-weight: 500;
    font-size: 15px;
    color: var(--text-secondary);
    position: relative;
    padding: var(--spacing-sm) 0;
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
}

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

.mobile-menu-btn {
    display: none;
    width: 44px;
    height: 44px;
    border-radius: var(--radius-md);
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
}

.mobile-menu-btn svg {
    width: 24px;
    height: 24px;
    stroke: var(--text-primary);
}

/* Mobile Navigation */
.mobile-nav {
    position: fixed;
    top: 0;
    right: -100%;
    width: 100%;
    max-width: 400px;
    height: 100vh;
    background: white;
    box-shadow: var(--shadow-xl);
    z-index: 2000;
    transition: right var(--transition-normal);
    display: flex;
    flex-direction: column;
}

.mobile-nav.active {
    right: 0;
}

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

.close-btn {
    width: 44px;
    height: 44px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
}

.close-btn svg {
    width: 24px;
    height: 24px;
    stroke: var(--text-primary);
}

.mobile-nav-links {
    flex: 1;
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.mobile-nav-link {
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    font-weight: 500;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

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

.mobile-nav-actions {
    padding: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

/* ===================================
   HERO SECTION
   =================================== */

.hero {
    padding: var(--spacing-4xl) 0;
    background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.1) 0%, transparent 70%);
    border-radius: 50%;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.hero-text {
    z-index: 1;
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    background: white;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-full);
    font-size: 14px;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
}

.badge svg {
    width: 16px;
    height: 16px;
}

.hero h1 {
    margin-bottom: var(--spacing-lg);
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--primary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-2xl);
    max-width: 600px;
}

.hero-actions {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-3xl);
    flex-wrap: wrap;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
}

.hero-stats .stat {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.stat-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-lg);
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.stat-icon svg {
    width: 24px;
    height: 24px;
    stroke: white;
}

.stat div {
    display: flex;
    flex-direction: column;
}

.stat-value {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    font-family: var(--font-heading);
}

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

/* Hero Visual */
.hero-visual {
    position: relative;
    height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-circle {
    width: 400px;
    height: 400px;
    border-radius: 50%;
    background: var(--gradient-primary);
    opacity: 0.1;
    position: absolute;
}

.floating-card {
    position: absolute;
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    animation: float 3s ease-in-out infinite;
}

.floating-card svg {
    width: 32px;
    height: 32px;
    stroke: var(--primary-color);
}

.floating-card span {
    font-weight: 600;
    color: var(--text-primary);
}

.card-1 {
    top: 10%;
    left: 10%;
}

.card-2 {
    top: 50%;
    right: 5%;
    animation-delay: 1s;
}

.card-3 {
    bottom: 15%;
    left: 15%;
    animation-delay: 2s;
}

/* ===================================
   SECTION STYLES
   =================================== */

section {
    padding: var(--spacing-4xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.section-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-full);
    font-size: 14px;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: var(--spacing-lg);
}

.section-badge svg {
    width: 16px;
    height: 16px;
}

.section-header h2 {
    margin-bottom: var(--spacing-md);
}

.section-header p {
    font-size: 1.125rem;
    max-width: 700px;
    margin: 0 auto;
}

/* ===================================
   FEATURES SECTION
   =================================== */

.features {
    background: var(--bg-secondary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-xl);
}

.feature-card {
    background: white;
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
    border: 2px solid transparent;
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-light);
}

.feature-icon {
    width: 64px;
    height: 64px;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-lg);
}

.feature-icon svg {
    width: 32px;
    height: 32px;
    stroke: white;
}

.feature-icon.purple {
    background: var(--gradient-physics);
}

.feature-icon.blue {
    background: var(--gradient-math);
}

.feature-icon.green {
    background: var(--gradient-biology);
}

.feature-icon.orange {
    background: linear-gradient(135deg, #F59E0B 0%, #EF4444 100%);
}

.feature-icon.pink {
    background: var(--gradient-chemistry);
}

.feature-icon.teal {
    background: linear-gradient(135deg, #14B8A6 0%, #06B6D4 100%);
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
}

.feature-card p {
    font-size: 1rem;
    line-height: 1.7;
}

/* ===================================
   COURSES SECTION
   =================================== */

.courses {
    background: white;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-xl);
}

.course-card {
    background: white;
    border-radius: var(--radius-2xl);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-normal);
    cursor: pointer;
    border: 2px solid transparent;
}

.course-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-light);
}

.course-header {
    padding: var(--spacing-2xl);
    position: relative;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.physics-gradient {
    background: var(--gradient-physics);
}

.chemistry-gradient {
    background: var(--gradient-chemistry);
}

.math-gradient {
    background: var(--gradient-math);
}

.biology-gradient {
    background: var(--gradient-biology);
}

.course-icon {
    font-size: 64px;
}

.course-badge {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(255, 255, 255, 0.95);
    border-radius: var(--radius-full);
    font-size: 12px;
    font-weight: 700;
    color: var(--primary-color);
    box-shadow: var(--shadow-sm);
}

.course-body {
    padding: var(--spacing-2xl);
}

.course-body h3 {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-md);
}

.course-body > p {
    font-size: 1rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-secondary);
}

.course-meta {
    display: flex;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.course-meta span {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.course-meta svg {
    width: 16px;
    height: 16px;
}

.course-topics {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
}

.topic-tag {
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--bg-secondary);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.course-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
}

.course-rating {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.course-rating svg {
    width: 20px;
    height: 20px;
    fill: #F59E0B;
    stroke: #F59E0B;
}

.course-rating span:first-of-type {
    font-weight: 700;
    color: var(--text-primary);
}

.reviews {
    font-size: 0.875rem;
    color: var(--text-light);
}

/* ===================================
   COURSE DETAIL MODAL
   =================================== */

.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    z-index: 3000;
    display: none;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
}

.modal.active {
    display: flex;
}

.modal-content {
    background: white;
    border-radius: var(--radius-2xl);
    max-width: 600px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    animation: modalSlideIn 0.3s ease;
}

.modal-large {
    max-width: 900px;
}

.close-modal {
    position: absolute;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
}

.close-modal svg {
    width: 20px;
    height: 20px;
    stroke: var(--text-primary);
}

.close-modal:hover {
    background: var(--bg-tertiary);
}

.course-detail {
    padding: var(--spacing-2xl);
}

.course-detail-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-xl);
    border-bottom: 2px solid var(--border-color);
}

.course-detail-icon {
    font-size: 72px;
}

.course-detail-header h2 {
    font-size: 2rem;
    margin-bottom: var(--spacing-sm);
}

.course-tabs {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xl);
    border-bottom: 2px solid var(--border-color);
}

.course-tab {
    padding: var(--spacing-md) var(--spacing-lg);
    font-weight: 600;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    border-bottom: 3px solid transparent;
    margin-bottom: -2px;
}

.course-tab.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.course-tab svg {
    width: 18px;
    height: 18px;
}

.course-tab-content {
    display: none;
}

.course-tab-content.active {
    display: block;
}

/* Chapters List */
.chapters-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.chapter-item {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    transition: all var(--transition-fast);
    cursor: pointer;
}

.chapter-item:hover {
    background: var(--bg-tertiary);
    transform: translateX(4px);
}

.chapter-number {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    background: var(--gradient-primary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.125rem;
    flex-shrink: 0;
}

.chapter-info {
    flex: 1;
}

.chapter-info h4 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
}

.chapter-info p {
    font-size: 0.875rem;
    color: var(--text-light);
}

.chapter-duration {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.chapter-duration svg {
    width: 16px;
    height: 16px;
}

/* About Course */
.about-course h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-lg);
}

.learning-points {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.learning-points li {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    font-size: 1rem;
    color: var(--text-secondary);
}

.learning-points svg {
    width: 24px;
    height: 24px;
    stroke: var(--success-color);
    flex-shrink: 0;
    margin-top: 2px;
}

/* Reviews */
.reviews-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.review-card {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
}

.review-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.reviewer-avatar {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-full);
    background: var(--gradient-primary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.25rem;
}

.review-header h4 {
    font-size: 1rem;
    margin-bottom: var(--spacing-xs);
}

.review-rating {
    display: flex;
    gap: 4px;
}

.review-rating svg {
    width: 16px;
    height: 16px;
    fill: #F59E0B;
    stroke: #F59E0B;
}

.review-card p {
    font-size: 0.9375rem;
    line-height: 1.6;
}

/* ===================================
   ABOUT SECTION
   =================================== */

.about {
    background: var(--bg-secondary);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.about-text {
    max-width: 600px;
}

.about-text h2 {
    margin-bottom: var(--spacing-lg);
}

.about-text p {
    margin-bottom: var(--spacing-lg);
}

.about-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.about-feature {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 600;
    color: var(--text-primary);
}

.about-feature svg {
    width: 20px;
    height: 20px;
    stroke: var(--success-color);
}

.founder-info {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.founder-avatar {
    width: 64px;
    height: 64px;
    border-radius: var(--radius-full);
    background: var(--gradient-primary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 2rem;
}

.founder-info h4 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
}

.founder-info p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
}

.stat-box {
    background: white;
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.stat-box:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.stat-box svg {
    width: 48px;
    height: 48px;
    stroke: var(--primary-color);
    margin: 0 auto var(--spacing-md);
}

.stat-box h3 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-box p {
    font-size: 1rem;
    color: var(--text-secondary);
}

/* ===================================
   CONTACT SECTION
   =================================== */

.contact {
    background: white;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
}

.contact-info {
    max-width: 500px;
}

.contact-info h2 {
    margin-bottom: var(--spacing-lg);
}

.contact-info p {
    margin-bottom: var(--spacing-2xl);
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.contact-method {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    transition: all var(--transition-normal);
    border: 2px solid transparent;
}

.contact-method:hover {
    background: white;
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
    transform: translateX(4px);
}

.method-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.method-icon svg {
    width: 28px;
    height: 28px;
    stroke: white;
}

.whatsapp .method-icon {
    background: linear-gradient(135deg, #25D366 0%, #128C7E 100%);
}

.email .method-icon {
    background: var(--gradient-primary);
}

.instagram .method-icon {
    background: linear-gradient(135deg, #F58529 0%, #DD2A7B 50%, #8134AF 100%);
}

.contact-method h4 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
}

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

.contact-method svg:last-child {
    width: 20px;
    height: 20px;
    stroke: var(--text-light);
    margin-left: auto;
}

/* Contact Form */
.contact-form-container {
    background: var(--bg-secondary);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-lg);
}

.contact-form h3 {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-xl);
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

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

.form-group label svg {
    width: 18px;
    height: 18px;
    stroke: var(--primary-color);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: var(--spacing-md);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 15px;
    transition: all var(--transition-fast);
    background: white;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

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

.form-options {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-lg);
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.9375rem;
    color: var(--text-secondary);
    cursor: pointer;
}

.checkbox-label input {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.forgot-link {
    font-size: 0.9375rem;
    color: var(--primary-color);
    font-weight: 600;
}

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

/* ===================================
   AUTH FORMS
   =================================== */

.auth-form {
    padding: var(--spacing-2xl);
}

.auth-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.auth-header svg {
    width: 64px;
    height: 64px;
    stroke: var(--primary-color);
    margin: 0 auto var(--spacing-lg);
}

.auth-header h2 {
    font-size: 2rem;
    margin-bottom: var(--spacing-sm);
}

.auth-header p {
    font-size: 1rem;
    color: var(--text-secondary);
}

.auth-footer {
    text-align: center;
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--border-color);
}

.auth-footer p {
    font-size: 0.9375rem;
}

.auth-footer a {
    color: var(--primary-color);
    font-weight: 600;
}

.auth-footer a:hover {
    text-decoration: underline;
}

/* ===================================
   FOOTER
   =================================== */

.footer {
    background: var(--text-primary);
    color: white;
    padding: var(--spacing-3xl) 0 var(--spacing-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: var(--spacing-3xl);
    margin-bottom: var(--spacing-3xl);
}

.footer-col h4 {
    color: white;
    font-size: 1.125rem;
    margin-bottom: var(--spacing-lg);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-family: var(--font-heading);
    font-size: 28px;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

.footer-logo svg {
    width: 36px;
    height: 36px;
    stroke: white;
}

.footer-col p {
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: var(--spacing-lg);
}

.footer-powered {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    font-size: 0.9375rem;
}

.footer-powered span {
    color: rgba(255, 255, 255, 0.7);
}

.footer-powered strong {
    color: white;
    font-weight: 700;
}

.footer-col ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

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

.footer-col ul li a:hover {
    color: white;
    padding-left: var(--spacing-sm);
}

.contact-list li {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.contact-list svg {
    width: 18px;
    height: 18px;
    stroke: rgba(255, 255, 255, 0.7);
}

.footer-bottom {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: var(--spacing-xl);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9375rem;
}

.footer-social {
    display: flex;
    gap: var(--spacing-md);
}

.social-link {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.social-link:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

.social-link svg {
    width: 20px;
    height: 20px;
    stroke: white;
}

/* ===================================
   WHATSAPP FLOAT BUTTON
   =================================== */

.whatsapp-float {
    position: fixed;
    bottom: var(--spacing-xl);
    right: var(--spacing-xl);
    width: 64px;
    height: 64px;
    border-radius: var(--radius-full);
    background: linear-gradient(135deg, #25D366 0%, #128C7E 100%);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-xl);
    z-index: 999;
    transition: all var(--transition-normal);
    animation: pulse 2s ease-in-out infinite;
}

.whatsapp-float:hover {
    transform: scale(1.1);
    box-shadow: 0 20px 40px rgba(37, 211, 102, 0.4);
}

.whatsapp-float svg {
    width: 32px;
    height: 32px;
    stroke: white;
}

/* ===================================
   TOAST NOTIFICATION
   =================================== */

.toast {
    position: fixed;
    bottom: var(--spacing-xl);
    left: 50%;
    transform: translateX(-50%) translateY(200%);
    background: var(--text-primary);
    color: white;
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    box-shadow: var(--shadow-xl);
    z-index: 9999;
    transition: transform var(--transition-normal);
}

.toast.show {
    transform: translateX(-50%) translateY(0);
}

.toast svg {
    width: 24px;
    height: 24px;
    stroke: var(--success-color);
}

/* ===================================
   ANIMATIONS
   =================================== */

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-20px);
    }
}

@keyframes pulse {
    0%, 100% {
        box-shadow: 0 0 0 0 rgba(37, 211, 102, 0.7);
    }
    50% {
        box-shadow: 0 0 0 20px rgba(37, 211, 102, 0);
    }
}

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

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* ===================================
   RESPONSIVE DESIGN
   =================================== */

@media (max-width: 1024px) {
    .hero-content,
    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-2xl);
    }
    
    .hero-visual {
        height: 400px;
    }
    
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .nav-actions .btn-secondary,
    .nav-actions .btn-primary {
        display: none;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .hero {
        padding: var(--spacing-3xl) 0;
    }
    
    .hero-stats {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .hero-visual {
        display: none;
    }
    
    .hero-actions {
        flex-direction: column;
        width: 100%;
    }
    
    .hero-actions button {
        width: 100%;
    }
    
    .features-grid,
    .courses-grid {
        grid-template-columns: 1fr;
    }
    
    .about-stats {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-2xl);
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: var(--spacing-lg);
        text-align: center;
    }
    
    .modal-content {
        max-width: 95%;
        margin: var(--spacing-md);
    }
    
    .course-tabs {
        overflow-x: auto;
    }
    
    .whatsapp-float {
        width: 56px;
        height: 56px;
        bottom: var(--spacing-lg);
        right: var(--spacing-lg);
    }
    
    .whatsapp-float svg {
        width: 28px;
        height: 28px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-md);
    }
    
    section {
        padding: var(--spacing-2xl) 0;
    }
    
    .hero-stats .stat {
        flex-direction: column;
        text-align: center;
    }
    
    .about-features {
        grid-template-columns: 1fr;
    }
}