:root {
    --bg-main: #050505;
    --bg-card: #111111;
    --bg-highlight: #1a1a1a;
    --text-primary: #f8f9fa;
    --text-secondary: #9ca3af;
    --border-color: #262626;
    --accent-glow: rgba(59, 130, 246, 0.5);
    --btn-primary: linear-gradient(135deg, #2563eb, #3b82f6);
    --btn-hover: linear-gradient(135deg, #1d4ed8, #2563eb);
    --radius-lg: 16px;
    --radius-md: 8px;
    --transition: 0.3s ease;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-main);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    scroll-behavior: smooth;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.text-center { text-align: center; }
.justify-center { justify-content: center; }
.mt-4 { margin-top: 2rem; }

/* Typography */
h1, h2, h3 { line-height: 1.2; font-weight: 700; }
h1 { font-size: clamp(2.5rem, 5vw, 4.5rem); letter-spacing: -0.02em; margin-bottom: 1rem; }
h2 { font-size: clamp(2rem, 4vw, 3rem); margin-bottom: 1.5rem; letter-spacing: -0.01em; }
h3 { font-size: 1.25rem; margin-bottom: 0.75rem; }
p { color: var(--text-secondary); margin-bottom: 1rem; font-size: 1.125rem; max-width: 700px; margin-left: auto; margin-right: auto; }

/* Header */
.site-header {
    position: sticky;
    top: 0;
    background: rgba(5, 5, 5, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 100;
}
.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}
.brand-logo {
    color: var(--text-primary);
    text-decoration: none;
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: 0.5px;
}
.main-nav a {
    color: var(--text-secondary);
    text-decoration: none;
    margin-left: 24px;
    font-size: 0.95rem;
    transition: var(--transition);
}
.main-nav a:hover, .main-nav a:focus {
    color: var(--text-primary);
}

/* Hero Section */
.hero {
    padding: 120px 0 80px;
    text-align: center;
    position: relative;
}
.hero::before {
    content: '';
    position: absolute;
    top: -100px;
    left: 50%;
    transform: translateX(-50%);
    width: 600px;
    height: 400px;
    background: var(--accent-glow);
    filter: blur(120px);
    z-index: -1;
    opacity: 0.3;
}
.badge {
    display: inline-block;
    padding: 6px 16px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 999px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    letter-spacing: 1px;
}

/* Buttons */
.cta-group {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 2.5rem;
}
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    border: none;
}
.btn-primary {
    background: var(--btn-primary);
    color: #fff;
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.2);
}
.btn-primary:hover, .btn-primary:focus {
    background: var(--btn-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}
.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}
.btn-secondary:hover, .btn-secondary:focus {
    background: rgba(255, 255, 255, 0.05);
    border-color: #404040;
}

/* Sections */
section { padding: 80px 0; }

/* Grid Cards */
.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
    margin-top: 40px;
}
.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 32px;
    border-radius: var(--radius-lg);
    transition: var(--transition);
}
.feature-card:hover {
    border-color: #404040;
    transform: translateY(-4px);
}
.feature-card p { margin: 0; font-size: 1rem; }

/* Highlight */
.highlight-box {
    background: linear-gradient(180deg, var(--bg-card) 0%, var(--bg-highlight) 100%);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 64px 32px;
    text-align: center;
}
.highlight-box h2 { margin-bottom: 1rem; }
.highlight-box p { margin: 0 auto; }

/* FAQ */
.faq-list { max-width: 800px; margin: 40px auto 0; }
.faq-item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    margin-bottom: 16px;
    overflow: hidden;
}
.faq-item summary {
    padding: 24px;
    font-size: 1.125rem;
    font-weight: 600;
    cursor: pointer;
    list-style: none;
    position: relative;
    outline: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
    content: '+';
    position: absolute;
    right: 24px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.5rem;
    color: var(--text-secondary);
    transition: var(--transition);
}
.faq-item[open] summary::after { content: '−'; }
.faq-content {
    padding: 0 24px 24px;
    color: var(--text-secondary);
}
.faq-content p { margin: 0; font-size: 1rem; text-align: left; }

/* Footer */
.site-footer {
    padding: 40px 0;
    border-top: 1px solid var(--border-color);
    margin-top: 40px;
}
.site-footer p { font-size: 0.875rem; margin: 0; }

/* Focus States for Accessibility */
a:focus-visible, button:focus-visible, summary:focus-visible {
    outline: 2px solid #3b82f6;
    outline-offset: 4px;
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .main-nav { display: none; /* Keep simple for static HTML/CSS */ }
    section { padding: 60px 0; }
    .hero { padding: 80px 0 60px; }
    .cta-group { flex-direction: column; width: 100%; max-width: 300px; margin-left: auto; margin-right: auto; }
    .btn { width: 100%; }
}