/* CSS Variables */
:root {
    --color-white: #ffffff;
    --color-blue-50: #eff6ff;
    --color-blue-100: #dbeafe;
    --color-blue-200: #bfdbfe;
    --color-blue-400: #60a5fa;
    --color-blue-600: #2563eb;
    --color-blue-700: #1d4ed8;
    --color-purple-400: #c084fc;
    --color-purple-500: #a855f7;
    --color-pink-500: #ec4899;
    --color-yellow-400: #facc15;
    --color-gray-50: #f9fafb;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-500: #6b7280;
    --color-gray-600: #4b5563;
    --color-gray-700: #374151;
    --color-gray-800: #1f2937;
    --color-gray-900: #111827;
    
    --spacing-1: 0.25rem;
    --spacing-2: 0.5rem;
    --spacing-3: 0.75rem;
    --spacing-4: 1rem;
    --spacing-6: 1.5rem;
    --spacing-8: 2rem;
    --spacing-10: 2.5rem;
    --spacing-12: 3rem;
    --spacing-16: 4rem;
    --spacing-20: 5rem;
    
    --font-sans: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --radius: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
}

/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-sans);
    color: var(--color-gray-800);
    background-color: var(--color-white);
    line-height: 1.5;
}

.container {
    max-width: 72rem;
    margin: 0 auto;
    padding: 0 var(--spacing-4);
}

.hidden {
    display: none !important;
}

/* Header/Navigation */
.header {
    background-color: var(--color-white);
    padding: var(--spacing-4) var(--spacing-4);
    position: sticky;
    top: 0;
    z-index: 50;
    box-shadow: var(--shadow-sm);
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    cursor: pointer;
}

.logo img {
    height: 2rem;
    border-radius: 8px;
}

.mobile-menu-btn {
    display: block;
    background: none;
    border: none;
    color: var(--color-gray-600);
    cursor: pointer;
    padding: var(--spacing-2);
}

.mobile-menu-btn:hover {
    color: var(--color-gray-900);
}

.desktop-nav {
    display: none;
}

.mobile-menu {
    margin-top: var(--spacing-4);
    padding: var(--spacing-4) 0;
    border-top: 1px solid var(--color-gray-100);
}

.mobile-nav {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-4);
    padding: 0 var(--spacing-4);
}

.mobile-nav a,
.desktop-nav a {
    color: var(--color-gray-600);
    text-decoration: none;
    transition: color 0.15s;
}

.mobile-nav a:hover,
.desktop-nav a:hover {
    color: var(--color-blue-600);
}

/* Hero Section */
.hero {
    background-color: var(--color-gray-50);
    padding: var(--spacing-20) var(--spacing-4);
    position: relative;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    inset: 0;
    opacity: 0.1;
    pointer-events: none;
}

.bg-circle {
    position: absolute;
    border-radius: 50%;
}

.circle-1 {
    top: 5rem;
    left: 5rem;
    width: 16rem;
    height: 16rem;
    background-color: var(--color-blue-400);
    transform: rotate(45deg);
}

.circle-2 {
    bottom: 5rem;
    right: 5rem;
    width: 20rem;
    height: 20rem;
    background-color: var(--color-purple-400);
    transform: rotate(-12deg);
}

.circle-3 {
    top: 10rem;
    right: 10rem;
    width: 10rem;
    height: 10rem;
    background-color: var(--color-yellow-400);
}

.hero-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
    z-index: 10;
}

.hero-text {
    margin-bottom: var(--spacing-10);
}

.badge {
    background-color: var(--color-blue-100);
    color: var(--color-blue-600);
    padding: var(--spacing-1) var(--spacing-3);
    border-radius: 9999px;
    font-size: 0.875rem;
    font-weight: 500;
    display: inline-block;
}

.hero-text h1 {
    font-size: 2.25rem;
    font-weight: 700;
    margin-top: var(--spacing-4);
    margin-bottom: var(--spacing-4);
}

.hero-text h2 {
    font-size: 1.5rem;
    color: var(--color-gray-700);
    font-weight: 500;
    margin-bottom: var(--spacing-6);
}

.hero-description {
    font-size: 1.25rem;
    color: var(--color-gray-600);
    margin-bottom: var(--spacing-8);
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-2);
    font-weight: 500;
    padding: var(--spacing-3) var(--spacing-6);
    border-radius: var(--radius-lg);
    transition: background-color 0.15s;
    text-decoration: none;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--color-blue-600);
    color: var(--color-white);
}

.btn-primary:hover {
    background-color: var(--color-blue-700);
}

.btn-large {
    padding: var(--spacing-3) var(--spacing-8);
}

.hero-image {
    width: 100%;
}

.hero-card {
    background-color: var(--color-white);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    padding: var(--spacing-2);
}

.hero-card-content {
    position: relative;
    width: 100%;
    border-radius: var(--radius-lg);
    aspect-ratio: 16 / 9;
    overflow: hidden;
}

.gradient-bg {
    position: absolute;
    inset: 0;
    background: linear-gradient(to bottom right, var(--color-purple-500), var(--color-pink-500), var(--color-yellow-400));
    opacity: 0.9;
}

.hero-card-text {
    position: relative;
    z-index: 10;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    text-align: center;
    padding: var(--spacing-6);
}

.hero-card-text h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-white);
    margin-bottom: var(--spacing-3);
}

.hero-card-text p {
    color: var(--color-white);
    opacity: 0.9;
    max-width: 28rem;
    margin-bottom: var(--spacing-6);
}

/* About Section */
.about {
    padding: var(--spacing-20) var(--spacing-4);
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-16);
}

.section-header h2 {
    font-size: 1.875rem;
    font-weight: 700;
    margin-bottom: var(--spacing-4);
}

.section-header p {
    font-size: 1.25rem;
    color: var(--color-gray-600);
    max-width: 48rem;
    margin: 0 auto;
}

.feature-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-8);
}

.feature-card {
    background-color: var(--color-white);
    border-radius: var(--radius-xl);
    padding: var(--spacing-8);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-gray-100);
}

.feature-icon {
    width: 3rem;
    height: 3rem;
    background-color: var(--color-blue-100);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-6);
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-3);
}

.feature-card p {
    color: var(--color-gray-600);
}

/* Syllabus Section */
.syllabus {
    padding: var(--spacing-20) var(--spacing-4);
    background-color: var(--color-gray-50);
}

.curriculum-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-4);
}

.curriculum-card {
    background-color: var(--color-white);
    border-radius: var(--radius-xl);
    padding: var(--spacing-6);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-gray-100);
    transition: box-shadow 0.3s;
}

.curriculum-card:hover {
    box-shadow: var(--shadow-md);
}

.curriculum-module {
    color: var(--color-blue-600);
    font-weight: 500;
    font-size: 0.875rem;
}

.curriculum-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-top: var(--spacing-1);
    margin-bottom: var(--spacing-2);
}

.curriculum-card p {
    color: var(--color-gray-600);
}

/* Instructor Section */
.instructor {
    padding: var(--spacing-20) var(--spacing-4);
}

.instructor-content {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.instructor-image {
    margin-bottom: var(--spacing-10);
}

.instructor-avatar {
    width: 12rem;
    height: 12rem;
    background: linear-gradient(to bottom right, var(--color-blue-100), var(--color-blue-200));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto;
}

.avatar-emoji {
    font-size: 5rem;
}

.instructor-text h2 {
    font-size: 1.875rem;
    font-weight: 700;
    margin-bottom: var(--spacing-4);
}

.instructor-text h3 {
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--color-gray-700);
    margin-bottom: var(--spacing-4);
}

.instructor-text p {
    font-size: 1.125rem;
    color: var(--color-gray-600);
    margin-bottom: var(--spacing-6);
}

.social-links {
    display: flex;
    gap: var(--spacing-4);
}

.social-links a {
    color: var(--color-gray-600);
    transition: color 0.15s;
}

.social-links a:hover {
    color: var(--color-blue-600);
}

/* Enrollment Section */
.enrollment {
    padding: var(--spacing-20) var(--spacing-4);
    background-color: var(--color-blue-50);
}

.enrollment-cta {
    display: flex;
    justify-content: center;
}

/* FAQ Section */
.faq {
    padding: var(--spacing-20) var(--spacing-4);
}

.faq-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-4);
    max-width: 56rem;
    margin: 0 auto;
}

.faq-item {
    border: 1px solid var(--color-gray-200);
    border-radius: var(--radius-xl);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-6);
    text-align: left;
    background: none;
    border: none;
    cursor: pointer;
    font-family: inherit;
}

.faq-question h3 {
    font-size: 1.125rem;
    font-weight: 500;
}

.faq-question .chevron {
    color: var(--color-gray-500);
    transition: transform 0.3s;
    flex-shrink: 0;
}

.faq-item.active .chevron {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 var(--spacing-6) var(--spacing-6);
    color: var(--color-gray-600);
}

.faq-contact {
    margin-top: var(--spacing-12);
    text-align: center;
}

.faq-contact p {
    color: var(--color-gray-600);
    margin-bottom: var(--spacing-4);
}

.faq-contact a {
    color: var(--color-blue-600);
    font-weight: 500;
    text-decoration: none;
}

.faq-contact a:hover {
    color: var(--color-blue-700);
}

/* Footer */
.footer {
    padding: var(--spacing-6) var(--spacing-4);
    background-color: var(--color-gray-50);
}

.footer-content {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-4);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-2);
}

.footer-logo img {
    height: 1.5rem;
    border-radius: 8px;
}

.footer-logo p {
    color: var(--color-gray-600);
    font-weight: 700;
}

.footer-social {
    display: flex;
    gap: var(--spacing-4);
}

.footer-social a {
    color: var(--color-gray-600);
    transition: color 0.15s;
}

.footer-social a:hover {
    color: var(--color-blue-600);
}

/* Responsive Design */
@media (min-width: 48rem) {
    /* Tablet and Desktop */
    
    .mobile-menu-btn {
        display: none;
    }
    
    .desktop-nav {
        display: flex;
        gap: var(--spacing-8);
    }
    
    .hero-text h1 {
        font-size: 3rem;
    }
    
    .hero-text h2 {
        font-size: 1.875rem;
    }
    
    .hero-content {
        flex-direction: row;
        align-items: center;
    }
    
    .hero-text {
        width: 50%;
        margin-bottom: 0;
    }
    
    .hero-image {
        width: 50%;
        padding-left: var(--spacing-10);
    }
    
    .hero-card-text h3 {
        font-size: 1.875rem;
    }
    
    .feature-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .curriculum-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .instructor-content {
        flex-direction: row;
        align-items: center;
    }
    
    .instructor-image {
        width: 33.33%;
        margin-bottom: 0;
    }
    
    .instructor-text {
        width: 66.67%;
        padding-left: var(--spacing-10);
    }
    
    .footer-content {
        flex-direction: row;
    }
}

/* Smooth scrolling */
html {
    scroll-behavior: smooth;
}

/* Accessibility */
.btn:focus-visible,
button:focus-visible,
a:focus-visible {
    outline: 2px solid var(--color-blue-600);
    outline-offset: 2px;
}