:root {
    /* Refined Color Palette */
    --color-soft-black: #09090b;
    --color-off-white: #fcfcfc;
    --color-white: #ffffff;
    --color-brand-teal: #0A8A8A;
    --color-brand-teal-dark: #076d6d;
    --color-brand-teal-light: #e0f2f2;
    --color-brand-teal-fade: rgba(10, 138, 138, 0.08);

    --color-gray-50: #f9fafb;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-300: #d1d5db;
    --color-gray-400: #9ca3af;
    --color-gray-600: #4b5563;
    --color-gray-800: #1f2937;

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

    /* Spacing System */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1.5rem;
    --spacing-md: 4rem;
    --spacing-lg: 10rem;
    /* Increased for breathability */
    --spacing-xl: 14rem;
    /* Increased for drama */

    /* Effects */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 20px;
    /* Refined for premium feel */
    --radius-full: 9999px;

    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-premium: 0 30px 60px -12px rgba(0, 0, 0, 0.08), 0 18px 36px -18px rgba(0, 0, 0, 0.1);
}

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

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

body {
    font-family: var(--font-primary);
    color: var(--color-soft-black);
    background-color: #f8f9fa;
    /* Soft off-white for card contrast */
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

.container {
    max-width: 1000px;
    /* Slightly tighter for premium focused feel */
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
    width: 100%;
}

/* Typography Enhancements */
h1,
h2,
h3 {
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.02em;
    color: var(--color-soft-black);
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    margin-bottom: var(--spacing-sm);
}

h2 {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    margin-bottom: var(--spacing-sm);
}

p {
    font-size: 1.125rem;
    color: var(--color-gray-600);
    margin-bottom: var(--spacing-sm);
    line-height: 1.7;
}

/* Section Dividers */
.section-divider {
    border: 0;
    height: 1px;
    background: linear-gradient(to right, transparent, var(--color-gray-200), transparent);
    width: 80%;
    max-width: 600px;
    margin: 0 auto;
    opacity: 0.6;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

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

.section {
    padding: 3rem 0;
    /* Tighter padding for card-based layout */
    animation: fadeInUp 1s cubic-bezier(0.23, 1, 0.32, 1) forwards;
}

/* Buttons - NuRevur Branding */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: var(--radius-md);
    /* Matching NuRevur card feel */
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    letter-spacing: 0.01em;
    border: none;
}

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

.btn-primary:hover {
    background-color: var(--color-brand-teal-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-outline {
    background-color: transparent;
    color: var(--color-brand-teal);
    border: 1.5px solid var(--color-brand-teal);
}

.btn-outline:hover {
    background-color: var(--color-brand-teal);
    color: var(--color-white);
    transform: translateY(-2px);
}

.btn-large {
    padding: 1.35rem 3.5rem;
    font-size: 1.25rem;
    letter-spacing: 0.02em;
}

/* Logo */
.logo {
    display: block;
    max-width: 160px;
    height: auto;
    margin: 0 auto var(--spacing-md);
}

/* Header */
.header {
    background-color: transparent;
    /* Changed to transparent as it's the hero */
    padding: var(--spacing-lg) 0 var(--spacing-md);
    text-align: center;
}

.header-title {
    max-width: 850px;
    margin: 0 auto var(--spacing-sm);
}

.header-sub {
    font-size: 1.25rem;
    color: var(--color-gray-600);
    max-width: 700px;
    margin: 0 auto 1.5rem;
}

.header-intro {
    font-size: 1.1rem;
    color: var(--color-gray-400);
    max-width: 650px;
    margin: 0 auto;
    font-weight: 400;
    line-height: 1.6;
}

/* Video Container */
.video-container {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    overflow: hidden;
    max-width: 900px;
    margin: 0 auto;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-premium);
    background-color: #000;
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

/* Section Dividers */
.section-divider {
    border: 0;
    height: 1px;
    background: linear-gradient(to right, transparent, rgba(10, 138, 138, 0.12), transparent);
    width: 60%;
    max-width: 500px;
    margin: 0 auto;
    opacity: 0.8;
}

/* Modern Section Cards */
.section-card {
    background: #FFFFFF;
    border: 1px solid #E5E5E5;
    border-radius: 10px;
    padding: 4rem 2rem;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.03);
    max-width: 900px;
    margin: 0 auto;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    text-align: center;
}

.section-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.05);
}

.section-card h2 {
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
}

.section-card p {
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* Content Blocks (Simulator, NuRi) */
.content-block {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

/* Enrollment CTA Section */
.cta-section {
    padding: 3rem 0;
}

.cta-box {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.cta-box h2 {
    margin-bottom: 1rem;
}

.cta-box p {
    margin-bottom: 2rem;
}

.cta-list {
    text-align: left;
    background: var(--color-white);
    padding: 2.5rem;
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-gray-100);
    margin: 2.5rem auto;
    box-shadow: var(--shadow-sm);
}

.cta-list h3 {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    color: var(--color-soft-black);
}

.cta-list ul {
    list-style: none;
}

.cta-list li {
    font-size: 1.125rem;
    color: var(--color-gray-600);
    margin-bottom: 1rem;
    padding-left: 1.75rem;
    position: relative;
    display: flex;
    align-items: center;
}

.cta-list li::before {
    content: "";
    position: absolute;
    left: 0;
    width: 10px;
    height: 10px;
    background-color: var(--color-brand-teal);
    border-radius: 50%;
    opacity: 0.6;
}

.cta-list li:last-child {
    margin-bottom: 0;
}

/* Footer */
.footer {
    background-color: var(--color-white);
    padding: var(--spacing-md) 0;
    border-top: 1px solid var(--color-gray-100);
    text-align: center;
}

.footer p {
    font-size: 1rem;
    color: var(--color-soft-black);
    margin-bottom: 0;
}

/* Visibility Control */
.bg-light {
    background-color: var(--color-gray-50);
}

.bg-teal-soft {
    background-color: var(--color-brand-teal-light);
}

.text-subtle {
    font-size: 0.95rem;
    font-weight: 300;
    color: var(--color-gray-400);
}

.footer-disclaimer {
    font-size: 0.85rem;
    font-weight: 300;
    color: #111111;
    margin-top: 1.5rem;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    :root {
        --spacing-lg: 4rem;
        /* Further reduced for mobile efficiency */
        --spacing-xl: 6rem;
    }

    .container {
        padding: 0 1.25rem;
    }

    h1 {
        font-size: clamp(2rem, 8vw, 2.5rem);
        /* Tighter scaling for mobile headers */
    }

    h2 {
        font-size: clamp(1.5rem, 6vw, 2rem);
    }

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

    .section-card {
        padding: 2.5rem 1.5rem;
        /* Balanced for mobile */
    }

    .btn {
        width: 100%;
        margin-bottom: 0.75rem;
        padding: 1rem 1.5rem;
    }

    .btn:last-child {
        margin-bottom: 0;
    }

    .btn-large {
        padding: 1.25rem 2rem;
        font-size: 1.15rem;
    }

    .cta-list {
        padding: 1.75rem 1.25rem;
        /* More breathable on small screens */
        margin: 2rem 0;
    }


}

/* NuRi Section Specifics */
#nuri .btn-outline {
    margin-top: 1rem;
}