:root {
    /* NuRevur Brand Colors adapted to Udemy Palette */
    --color-brand-teal: #0A8A8A;
    --color-brand-teal-dark: #076d6d;
    --color-brand-teal-light: #e0f2f2;
    --color-brand-teal-fade: rgba(10, 138, 138, 0.08);

    /* Udemy-inspired Neutrals */
    --color-udemy-black: #1c1d1f;
    --color-udemy-gray-900: #2d2f31;
    --color-udemy-gray-700: #6a6f73;
    --color-udemy-gray-100: #f7f9fa;
    --color-white: #ffffff;

    /* Typography */
    --font-primary: 'Inter', system-ui, -apple-system, sans-serif;
    --font-display: 'Outfit', 'Inter', sans-serif;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 3rem;
    --spacing-xl: 5rem;

    /* Borders & Radius (Udemy uses very small radius) */
    --radius-sm: 0;
    --radius-md: 4px;
    --radius-lg: 8px;
    --radius-full: 9999px;

    /* Shadows (Udemy uses crisp shadows) */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, .08), 0 4px 12px rgba(0, 0, 0, .08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, .15);
    --shadow-premium: 0 2px 4px rgba(0, 0, 0, .08), 0 4px 12px rgba(0, 0, 0, .08);

    /* Transitions */
    --transition-base: all 250ms cubic-bezier(.4, 0, .2, 1);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    background-color: var(--color-white);
    color: var(--color-udemy-gray-900);
    line-height: 1.4;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* Typography */
h1,
h2,
h3,
h4 {
    font-family: var(--font-display);
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-soft-black);
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    letter-spacing: -0.02em;
}

h2 {
    font-size: clamp(2rem, 4vw, 2.5rem);
    letter-spacing: -0.01em;
}

h3 {
    font-size: 1.5rem;
}

p {
    font-size: 1.125rem;
    color: var(--color-gray-600);
}

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

/* Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

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

/* Components */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0 1.2rem;
    height: 48px;
    font-size: 1rem;
    font-weight: 700;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition-base);
    border: 1px solid transparent;
    gap: 0.5rem;
    text-align: center;
}

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

.btn-primary:hover {
    background-color: var(--color-udemy-gray-900);
    transform: none;
    box-shadow: none;
}

.btn-large {
    height: 56px;
    padding: 0 2.4rem;
    font-size: 1.1rem;
}

.btn-secondary {
    background-color: var(--color-brand-teal-light);
    color: var(--color-brand-teal-dark);
}

.btn-secondary:hover {
    background-color: var(--color-brand-teal);
    color: var(--color-white);
}

.btn-outline {
    background-color: transparent;
    border: 2px solid var(--color-brand-teal);
    color: var(--color-brand-teal);
}

.btn-outline:hover {
    background-color: var(--color-brand-teal);
    color: var(--color-white);
}

.card {
    background: var(--color-white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-gray-100);
    transition: var(--transition-base);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-premium);
}

/* Navigation */
.navbar {
    position: sticky;
    top: 0;
    background: var(--color-white);
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0, 0, 0, .08);
    height: 72px;
    display: flex;
    align-items: center;
}

.nav-container {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2.4rem;
}

.logo-text {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--color-brand-teal);
}

.logo-text span {
    color: var(--color-soft-black);
    font-weight: 400;
    font-size: 1.1rem;
    margin-left: 0.5rem;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    font-weight: 500;
    color: var(--color-gray-600);
}

.nav-link:hover {
    color: var(--color-brand-teal);
}

.nav-cta {
    display: flex;
    gap: 1rem;
}

/* Footer */
.footer {
    background: var(--color-soft-black);
    color: var(--color-white);
    padding: var(--spacing-xl) 0 var(--spacing-md);
}

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

.footer-brand h4 {
    color: var(--color-white);
    margin-bottom: var(--spacing-sm);
    font-size: 1.5rem;
}

.footer-brand p {
    color: var(--color-gray-400);
    margin-bottom: var(--spacing-md);
}

.footer-links h5 {
    color: var(--color-white);
    margin-bottom: var(--spacing-md);
    font-size: 1.1rem;
}

.footer-links ul {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.75rem;
}

.footer-links a {
    color: var(--color-gray-400);
}

.footer-links a:hover {
    color: var(--color-brand-teal);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-md);
    text-align: center;
    color: var(--color-gray-400);
    font-size: 0.875rem;
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-fade-in {
    animation: fadeIn 0.8s ease forwards;
}

/* Specific Section Styles */
.hero {
    padding-top: calc(var(--spacing-xl) + 2rem);
    background: linear-gradient(rgba(255, 255, 255, 0.9), rgba(255, 255, 255, 0.8)),
        url('../img/hero-bg.png');
    background-size: cover;
    background-position: center;
    text-align: center;
    min-height: 80vh;
    display: flex;
    align-items: center;
}

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

.hero h1 {
    margin-bottom: 1.5rem;
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-lg);
}

.hero-btns {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
}

/* Module Accordion */
.accordion-item {
    background: var(--color-white);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-sm);
    border: 1px solid var(--color-gray-200);
    overflow: hidden;
}

.accordion-header {
    padding: var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    background: var(--color-white);
    transition: var(--transition-base);
}

.accordion-header:hover {
    background: var(--color-gray-50);
}

.accordion-title {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.module-number {
    background: var(--color-brand-teal-light);
    color: var(--color-brand-teal-dark);
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.875rem;
}

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
    padding: 0 var(--spacing-md);
}

.accordion-content.active {
    max-height: 500px;
    padding: 0 var(--spacing-md) var(--spacing-md);
}

/* Responsive */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

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

    .hero-btns {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .footer-grid {
        grid-template-columns: 1fr;
    }
}