:root {
    --bg-dark: #0f172a;
    --bg-card: #1e293b;
    --primary-color: #38bdf8; /* Sky blue */
    --accent-color: #818cf8; /* Indigo */
    --text-main: #f1f5f9;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --gradient-hero: linear-gradient(135deg, #0f172a 0%, #1e1b4b 100%);
    --shadow-card: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 0;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* Header */
header {
    background-color: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 0 20px;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    height: 70px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--text-main);
    letter-spacing: -0.025em;
}

.brand-logo {
    height: 40px; /* Adjust as needed */
    vertical-align: middle;
}

nav {
    display: flex;
    gap: 20px;
    align-items: center;
}

nav a {
    text-decoration: none;
    color: var(--text-muted);
    font-size: 0.95rem;
    font-weight: 500;
    transition: color 0.2s;
}

nav a:hover {
    color: var(--primary-color);
}

.nav-btn {
    background-color: rgba(56, 189, 248, 0.1);
    color: var(--primary-color) !important;
    padding: 6px 16px;
    border-radius: 9999px;
    font-weight: 600;
}

.nav-btn:hover {
    background-color: rgba(56, 189, 248, 0.2);
}

/* Hero Section */
.hero {
    background: var(--gradient-hero);
    padding: 80px 20px 60px;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin: 0 0 20px;
    background: linear-gradient(to right, #fff, #94a3b8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.05em;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-muted);
    max-width: 700px;
    margin: 0 auto 40px;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 60px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s;
}

.btn-primary {
    background-color: var(--primary-color);
    color: #0f172a;
}

.btn-primary:hover {
    background-color: #0ea5e9;
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--text-main);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.15);
}

.email-text {
    color: var(--text-main);
    text-decoration: none;
    transition: color 0.2s;
}

.email-text:hover {
    color: var(--primary-color);
}

.hero-image-container {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.3), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
    border: 1px solid var(--border-color);
}

.hero-image {
    width: 100%;
    height: auto;
    display: block;
}

/* Main Content */
.main-content {
    padding: 60px 20px;
}

section,
article {
    margin-bottom: 80px;
    scroll-margin-top: 100px; /* For anchor links */
}

.content-block {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 40px;
    box-shadow: var(--shadow-card);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 20px;
}

h2 {
    font-size: 2rem;
    margin: 0;
    color: var(--text-main);
}

h3 {
    font-size: 1.5rem;
    margin: 0 0 15px;
    color: var(--text-main);
}

h4 {
    font-size: 1.15rem;
    color: var(--primary-color);
    margin: 25px 0 10px;
}

p {
    color: var(--text-muted);
    font-size: 1.1rem;
    margin-bottom: 20px;
}

.highlight-purpose {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--primary-color);
    text-align: center;
    margin: 40px auto;
    max-width: 800px;
}

strong {
    color: var(--text-main);
}

.badge {
    background-color: rgba(56, 189, 248, 0.1);
    color: var(--primary-color);
    padding: 6px 12px;
    border-radius: 9999px;
    font-size: 0.875rem;
    font-weight: 600;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    margin: 40px 0;
}

.stat-item {
    background-color: rgba(15, 23, 42, 0.5);
    padding: 24px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 5px;
}

.stat-label {
    display: block;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-main);
    margin-bottom: 8px;
}

.stat-desc {
    display: block;
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Feature Grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

/* Synthetic Section Grid */
.synthetic-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
    align-items: start;
}

@media (max-width: 900px) {
    .synthetic-grid {
        grid-template-columns: 1fr;
    }
}


/* Tech Details (Accordion) */
.tech-details-container {
    margin: 30px 0;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.tech-details {
    background-color: rgba(15, 23, 42, 0.3);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    transition: all 0.3s ease;
}

.tech-details[open] {
    background-color: rgba(15, 23, 42, 0.6);
    border-color: var(--primary-color);
}

.tech-details summary {
    padding: 16px 20px;
    cursor: pointer;
    font-weight: 600;
    color: var(--text-main);
    display: flex;
    align-items: center;
    list-style: none; /* Remove default triangle */
    user-select: none;
    transition: background-color 0.2s;
}

.tech-details summary:hover {
    background-color: rgba(255, 255, 255, 0.05);
}

/* Custom triangle indicator */
.tech-details summary::after {
    content: '+';
    margin-left: auto;
    font-size: 1.25rem;
    font-weight: 400;
    color: var(--primary-color);
    transition: transform 0.2s;
}

.tech-details[open] summary::after {
    content: '-';
    transform: rotate(0deg); /* Or rotate(45deg) if using + */
}

/* Hide default marker in WebKit */
.tech-details summary::-webkit-details-marker {
    display: none;
}

.details-content {
    padding: 0 20px 20px 20px;
    border-top: 1px solid transparent;
    animation: slideDown 0.3s ease-out;
}

.tech-details[open] .details-content {
    border-top-color: var(--border-color);
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-5px); }
    to { opacity: 1; transform: translateY(0); }
}


/* Image Gallery */
.image-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 40px;
}

.image-gallery.four-cols {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

figure {
    margin: 0;
    background-color: #000;
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--border-color);
    transition: transform 0.2s;
}

figure:hover {
    transform: translateY(-4px);
    border-color: var(--primary-color);
}

figure img {
    width: 100%;
    height: auto;
    display: block;
    object-fit: cover;
    aspect-ratio: 16/9; /* Enforce consistency */
}

figcaption {
    padding: 12px;
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-muted);
    background-color: rgba(15, 23, 42, 0.8);
    border-top: 1px solid var(--border-color);
}

/* FAQ Section */
.faq-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-top: 30px;
}

.faq-item {
    background-color: rgba(15, 23, 42, 0.5);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    transition: all 0.2s ease;
}

.faq-item:hover {
    border-color: var(--primary-color);
    background-color: rgba(15, 23, 42, 0.7);
}

.faq-item h3 {
    font-size: 1.15rem;
    margin: 0 0 12px;
    color: var(--primary-color);
    font-weight: 600;
}

.faq-item p {
    margin: 0;
    font-size: 1rem;
    line-height: 1.7;
}

.faq-item a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.2s;
}

.faq-item a:hover {
    color: var(--accent-color);
    text-decoration: underline;
}

/* Footer */
footer {
    background-color: var(--bg-card);
    border-top: 1px solid var(--border-color);
    padding: 40px 20px;
    margin-top: auto;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-links a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.2s;
}

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

/* Responsive adjustments */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .content-block {
        padding: 24px;
    }

    .header-container {
        height: auto;
        flex-direction: column;
        padding: 15px 0;
    }

    nav {
        margin-top: 15px;
        flex-wrap: wrap;
        justify-content: center;
    }
}