/* ===========================
   CSS Variables & Reset
   =========================== */
:root {
    /* Light Theme Colors - WCAG AA Compliant */
    /* All text colors meet WCAG 2.1 Level AA standards (4.5:1 contrast ratio) */
    --bg-primary: #FFFFFF;
    --bg-secondary: #F9FAFB;
    --bg-card: #FFFFFF;
    --text-primary: #111827;        /* Contrast: 15.68:1 on white */
    --text-secondary: #4B5563;      /* Contrast: 7.37:1 on white */
    --text-muted: #6B7280;          /* Contrast: 5.39:1 on white */

    /* Brand Colors */
    --purple-primary: #7C3AED;      /* Used for backgrounds and large text */
    --purple-dark: #5B21B6;         /* Darker variant */
    --purple-light: #A78BFA;        /* Light variant */
    --purple-lighter: #DDD6FE;      /* Very light variant */
    --purple-bg: #F5F3FF;           /* Background tint */

    /* Accessibility-enhanced colors for light theme */
    --text-purple: #6D28D9;         /* Contrast: 6.79:1 on white - Used for purple text on light backgrounds */

    /* Accent Colors */
    --accent-gradient: linear-gradient(135deg, #7C3AED 0%, #A78BFA 100%);

    /* UI Elements */
    --border-color: #E5E7EB;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;

    /* Spacing */
    --container-max: 1200px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
}

/* Dark Theme */
body.dark-theme {
    --bg-primary: #7C3AED;
    --bg-secondary: #FFFFFF;
    --bg-card: #FFFFFF;
    --text-primary: #FFFFFF;
    --text-secondary: #E9D5FF;
    --text-muted: #C4B5FD;
    --border-color: #A78BFA;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color var(--transition-base), color var(--transition-base);
    overflow-x: hidden;
}

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

/* ===========================
   Header & Navigation
   =========================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all var(--transition-base);
    backdrop-filter: blur(10px);
    background-color: rgba(255, 255, 255, 0.9);
}

.dark-theme .header {
    background-color: rgba(124, 58, 237, 0.95);
}

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

.nav-logo {
    flex-shrink: 0;
}

.nav-logo img {
    height: 90px;
    width: auto;
    object-fit: contain;
}

.logo-light {
    display: block;
    mix-blend-mode: multiply;
}

.logo-dark {
    display: none;
    height: 120px;
}

.dark-theme .logo-light {
    display: none;
}

.dark-theme .logo-dark {
    display: block;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
    margin: 0;
}

.nav-link {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color var(--transition-fast);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--purple-primary);
    transition: width var(--transition-base);
}

.dark-theme .nav-link::after {
    background: white;
}

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

.dark-theme .nav-link:hover {
    color: var(--purple-lighter);
}

.nav-link:hover::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-base);
}

.dark-theme .nav-toggle span {
    background: white;
}

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

.nav-menu-actions {
    display: none;
}

.nav-mobile-controls {
    display: none;
}

.theme-toggle-desktop,
.btn-desktop {
    display: flex;
}

.theme-toggle-icon,
.btn-mobile-menu {
    display: none;
}

.theme-toggle {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-base);
    color: var(--text-primary);
}

.dark-theme .theme-toggle {
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: white;
}

.theme-toggle:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

.dark-theme .theme-toggle:hover {
    background: rgba(255, 255, 255, 0.3);
}

.sun-icon {
    display: block;
}

.moon-icon {
    display: none;
}

.dark-theme .sun-icon {
    display: none;
}

.dark-theme .moon-icon {
    display: block;
}

.theme-toggle-label {
    display: none;
}

/* ===========================
   Buttons
   =========================== */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    text-align: center;
    transition: all var(--transition-base);
    border: none;
    cursor: pointer;
    font-size: 0.95rem;
}

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

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

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

.dark-theme .btn-primary:hover {
    background: var(--purple-lighter);
    color: var(--purple-dark);
}

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

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

.dark-theme .btn-cta {
    background: var(--purple-lighter);
    color: var(--purple-dark);
    border-color: var(--purple-lighter);
}

.btn-cta:hover {
    background: var(--purple-lighter);
    transform: translateY(-2px);
}

/* ===========================
   Hero Section
   =========================== */
.hero {
    padding: 8rem 0 4rem;
    background: var(--bg-primary);
    margin-top: 110px;
}

.dark-theme .hero {
    margin-top: 140px;
}

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

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

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--spacing-sm);
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--text-purple) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.dark-theme .hero-title {
    background: linear-gradient(135deg, #FFFFFF 0%, #DDD6FE 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-tagline {
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--text-purple);
    margin-bottom: var(--spacing-lg);
    letter-spacing: 0.5px;
}

.dark-theme .hero-tagline {
    color: var(--purple-lighter);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
    line-height: 1.7;
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.child-illustration {
    width: 100%;
    max-width: 400px;
    height: auto;
    filter: drop-shadow(0 20px 40px rgba(124, 58, 237, 0.3));
    animation: float 3s ease-in-out infinite;
}

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

/* ===========================
   Section Titles
   =========================== */
.section-title {
    font-size: 2.5rem;
    font-weight: 800;
    text-align: center;
    margin-bottom: var(--spacing-xl);
    color: var(--text-primary);
}

/* ===========================
   Why BeyondClass Section
   =========================== */
.why-section {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-secondary);
}

.dark-theme .why-section {
    background: #FFFFFF;
}

.dark-theme .why-section .section-title {
    color: #111827;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-2xl);
}

.feature-card {
    background: var(--bg-card);
    padding: var(--spacing-xl);
    border-radius: 16px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.dark-theme .feature-card {
    border: 1px solid #E5E7EB;
}

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

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--purple-bg);
    border-radius: 50%;
    color: var(--text-purple);
}

.dark-theme .feature-icon {
    background: var(--purple-bg);
    color: var(--text-purple);
}

.feature-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.dark-theme .feature-title {
    color: #111827;
}

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

.dark-theme .feature-description {
    color: #4B5563;
}

/* ===========================
   Programs Section
   =========================== */
.programs-section {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-primary);
}

.dark-theme .programs-section {
    background: #FFFFFF;
}

.dark-theme .programs-section .section-title {
    color: #111827;
}

.programs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-2xl);
}

.program-card {
    background: var(--purple-primary);
    color: white;
    padding: var(--spacing-xl);
    border-radius: 16px;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.dark-theme .program-card {
    background: var(--purple-primary);
    border: none;
}

.program-card::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    opacity: 0;
    transition: opacity var(--transition-slow);
}

.program-card:hover::before {
    opacity: 1;
}

.program-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: var(--shadow-xl);
}

.program-title {
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.program-description {
    font-size: 0.95rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.9;
    line-height: 1.6;
}

.program-link {
    color: white;
    text-decoration: none;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: gap var(--transition-base);
}

.program-link::after {
    content: '→';
    transition: transform var(--transition-base);
}

.program-link:hover {
    gap: 0.75rem;
}

.program-link:hover::after {
    transform: translateX(4px);
}

/* ===========================
   Impact Section
   =========================== */
.impact-section {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-secondary);
}

.dark-theme .impact-section {
    background: #FFFFFF;
}

.dark-theme .impact-section .section-title {
    color: #111827;
}

.impact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-2xl);
}

.impact-stat {
    background: var(--bg-card);
    padding: var(--spacing-xl);
    border-radius: 16px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

.dark-theme .impact-stat {
    border: 1px solid #E5E7EB;
}

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

.stat-number {
    font-size: 3rem;
    font-weight: 800;
    color: var(--text-purple);
    margin-bottom: var(--spacing-xs);
}

.dark-theme .stat-number {
    color: var(--text-purple);
}

.stat-label {
    font-size: 1rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.dark-theme .stat-label {
    color: #4B5563;
}

.impact-highlight {
    background: var(--purple-primary);
    color: white;
    padding: var(--spacing-xl);
    border-radius: 16px;
    grid-column: span 1;
}

.dark-theme .impact-highlight {
    background: var(--purple-primary);
    border: none;
}

.highlight-text {
    font-size: 1.1rem;
    font-style: italic;
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
}

.highlight-author {
    font-size: 0.9rem;
    opacity: 0.9;
    font-weight: 600;
}

/* ===========================
   CTA Section
   =========================== */
.cta-section {
    padding: var(--spacing-3xl) 0;
    background: var(--purple-primary);
    text-align: center;
}

.dark-theme .cta-section {
    background: var(--purple-primary);
}

.cta-container {
    max-width: 800px;
}

.cta-title {
    font-size: 3rem;
    font-weight: 800;
    color: white;
    margin-bottom: var(--spacing-xl);
}

/* ===========================
   Footer
   =========================== */
.footer {
    background: var(--bg-secondary);
    padding: var(--spacing-xl) 0 var(--spacing-md);
    border-top: 1px solid var(--border-color);
}

.dark-theme .footer {
    background: var(--purple-primary);
    border-top: 1px solid var(--purple-light);
}

.footer-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.footer-links {
    display: flex;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
}

.footer-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.dark-theme .footer-link {
    color: rgba(255, 255, 255, 0.8);
}

.footer-link:hover {
    color: var(--text-purple);
}

.dark-theme .footer-link:hover {
    color: white;
}

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

.social-link {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    color: var(--text-primary);
    transition: all var(--transition-base);
}

.dark-theme .social-link {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: white;
}

.social-link:hover {
    background: var(--purple-primary);
    color: white;
    transform: translateY(-2px);
    border-color: var(--purple-primary);
}

.dark-theme .social-link:hover {
    background: white;
    color: var(--purple-primary);
    border-color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.9rem;
}

.dark-theme .footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    color: rgba(255, 255, 255, 0.7);
}

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

/* Tablet */
@media (max-width: 968px) {
    .hero-container {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }

    .hero-content {
        text-align: center;
        max-width: 100%;
    }

    .hero-title {
        font-size: 2.8rem;
    }

    .hero-tagline {
        font-size: 1.3rem;
    }

    .hero-image {
        order: -1;
    }

    .child-illustration {
        max-width: 300px;
    }

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

    .cta-title {
        font-size: 2.2rem;
    }

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

    .impact-highlight {
        grid-column: span 2;
    }
}

/* Mobile */
@media (max-width: 768px) {
    .nav-logo img {
        height: 75px;
    }

    .logo-dark {
        height: 100px;
    }

    /* Show mobile controls (theme icon + hamburger) */
    .nav-mobile-controls {
        display: flex;
        align-items: center;
        gap: var(--spacing-md);
    }

    /* Hide desktop actions on mobile */
    .nav-actions {
        display: none;
    }

    .theme-toggle-desktop,
    .btn-desktop {
        display: none;
    }

    /* Show theme icon in mobile header */
    .theme-toggle-icon {
        display: flex;
        width: 40px;
        height: 40px;
        padding: 0;
        background: var(--bg-secondary);
        border: 1px solid var(--border-color);
        border-radius: 50%;
        align-items: center;
        justify-content: center;
        cursor: pointer;
        transition: all var(--transition-base);
        color: var(--text-primary);
    }

    .dark-theme .theme-toggle-icon {
        background: rgba(255, 255, 255, 0.2);
        border: 1px solid rgba(255, 255, 255, 0.3);
        color: white;
    }

    .theme-toggle-icon:hover {
        transform: scale(1.05);
    }

    /* Show mobile menu actions */
    .nav-menu-actions {
        display: block;
        padding-top: var(--spacing-md);
        margin-top: var(--spacing-md);
        border-top: 1px solid var(--border-color);
    }

    .dark-theme .nav-menu-actions {
        border-top: 1px solid rgba(255, 255, 255, 0.2);
    }

    .btn-mobile-menu {
        display: block;
        width: 100%;
        padding: var(--spacing-md);
        font-size: 1rem;
        text-align: center;
    }

    .nav-menu {
        position: fixed;
        top: 100px;
        left: 0;
        right: 0;
        background: var(--bg-primary);
        flex-direction: column;
        padding: var(--spacing-lg);
        border-bottom: 1px solid var(--border-color);
        transform: translateY(-100%);
        opacity: 0;
        transition: all var(--transition-base);
        pointer-events: none;
        box-shadow: var(--shadow-lg);
        max-height: calc(100vh - 100px);
        overflow-y: auto;
    }

    .dark-theme .nav-menu {
        top: 125px;
        border-bottom: 1px solid rgba(255, 255, 255, 0.3);
        max-height: calc(100vh - 125px);
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: all;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .hero {
        padding: 4rem 0 3rem;
        margin-top: 90px;
    }

    .dark-theme .hero {
        margin-top: 110px;
    }

    .child-illustration {
        max-width: 220px;
    }

    .hero-title {
        font-size: 2.2rem;
    }

    .hero-tagline {
        font-size: 1.2rem;
    }

    .hero-subtitle {
        font-size: 1.1rem;
    }

    .section-title {
        font-size: 1.8rem;
    }

    .features-grid,
    .programs-grid {
        grid-template-columns: 1fr;
    }

    .impact-grid {
        grid-template-columns: 1fr;
    }

    .impact-highlight {
        grid-column: span 1;
    }

    .cta-title {
        font-size: 1.8rem;
    }

    .footer-container {
        flex-direction: column;
        text-align: center;
    }

    .footer-links {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }

    .nav-logo img {
        height: 65px;
    }

    .logo-dark {
        height: 85px;
    }

    .hero {
        padding: 3rem 0 2rem;
        margin-top: 80px;
    }

    .dark-theme .hero {
        margin-top: 95px;
    }

    .child-illustration {
        max-width: 180px;
    }

    .hero-title {
        font-size: 1.8rem;
    }

    .hero-tagline {
        font-size: 1.1rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .btn-large {
        padding: 0.875rem 1.5rem;
        font-size: 1rem;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .feature-card,
    .program-card,
    .impact-stat {
        padding: var(--spacing-md);
    }

    .stat-number {
        font-size: 2.5rem;
    }

    .cta-title {
        font-size: 1.5rem;
    }
}

/* ===========================
   Animations & Utilities
   =========================== */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

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