/* Global Styles */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;600;700&display=swap');

:root {
    --bg-color: #050510;
    --text-primary: #ffffff;
    --text-secondary: #a0a0b0;
    --accent-primary: #8b5cf6;
    --accent-secondary: #3b82f6;
    --accent-tertiary: #ec4899;
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
    --glass-blur: 10px;
    --transition-speed: 0.3s;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

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

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

.fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in-up.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Utilities */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 30px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-speed) ease;
    border: none;
}

.btn-primary {
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary));
    color: white;
    box-shadow: 0 0 20px rgba(139, 92, 246, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 30px rgba(139, 92, 246, 0.5);
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    backdrop-filter: blur(5px);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--text-primary);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 1rem;
    background: linear-gradient(to right, #fff, #a0a0b0);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    font-size: 1.1rem;
}

/* Header */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 20px 0;
    background: rgba(5, 5, 16, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--glass-border);
    transition: background 0.3s ease, padding 0.3s ease;
}

header.scrolled {
    background: rgba(5, 5, 16, 0.95);
    padding: 15px 0;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.5);
}

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

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 1px;
    color: white;
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo span {
    color: var(--accent-primary);
}

.nav-links {
    display: flex;
    gap: 30px;
}

.nav-links a {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.nav-links a:hover {
    color: white;
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 6px;
    cursor: pointer;
    z-index: 1001;
}

.mobile-menu-btn span {
    display: block;
    width: 25px;
    height: 2px;
    background-color: white;
    transition: all 0.3s ease;
}

.mobile-menu-btn.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 6px);
}

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -6px);
}

/* Hero Section */
.hero {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding-top: 80px;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.hero-bg img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.4;
    filter: brightness(0.6);
}

.hero-bg::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 150px;
    background: linear-gradient(to top, var(--bg-color), transparent);
}

.hero-content {
    text-align: center;
    max-width: 800px;
    z-index: 1;
}

.hero h1 {
    font-size: 4rem;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    letter-spacing: -1px;
}

.hero h1 span {
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-tertiary));
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
}

/* Features Section */
.features {
    padding: 100px 0;
    position: relative;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.feature-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    padding: 30px;
    border-radius: 20px;
    transition: var(--transition-speed);
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-10px);
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--accent-primary);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    border-radius: 50%;
    background: rgba(139, 92, 246, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
}

.feature-icon img {
    width: 50px;
    height: 50px;
    object-fit: contain;
}

.feature-card h3 {
    margin-bottom: 15px;
    font-size: 1.5rem;
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Showcase Section */
.showcase {
    padding: 100px 0;
    background: linear-gradient(180deg, var(--bg-color) 0%, #0a0a20 50%, var(--bg-color) 100%);
}

.video-placeholder-large {
    width: 100%;
    height: 600px;
    background: #000;
    border-radius: 20px;
    border: 1px solid var(--glass-border);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    box-shadow: 0 0 50px rgba(139, 92, 246, 0.2);
}

.video-placeholder-large::before {
    content: 'Interactive World Model Demo';
    color: var(--text-secondary);
    font-size: 2rem;
    z-index: 2;
}

/* Footer */
footer {
    padding: 50px 0;
    border-top: 1px solid var(--glass-border);
    margin-top: 50px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 40px;
}

.footer-logo {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 20px;
}

.footer-links h4 {
    margin-bottom: 20px;
    color: white;
}

.footer-links ul li {
    margin-bottom: 10px;
}

.footer-links a {
    color: var(--text-secondary);
}

.footer-links a:hover {
    color: var(--accent-primary);
}

.legal {
    margin-top: 50px;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.8rem;
    display: flex;
    justify-content: center;
    gap: 20px;
}

/* Responsive */
@media (max-width: 768px) {
    .features-grid {
        grid-template-columns: 1fr;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 100%;
        height: 100vh;
        background: rgba(5, 5, 16, 0.98);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        transition: right 0.3s ease;
        z-index: 1000;
    }

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

    .nav-links a {
        font-size: 1.5rem;
    }

    .hero h1 {
        font-size: 2.5rem;
    }
}