/* Premium Design System Base */
:root {
    --bg-color: #05070a;
    --surface-color: #0d121c;
    --surface-hover: #151d2a;

    --text-primary: #f8f9fa;
    --text-secondary: #a0aab5;
    --text-tertiary: #6c757d;

    --accent-color: #2563eb;
    --accent-hover: #1d4ed8;

    --border-color: #1f2937;

    --font-sans: 'Inter', sans-serif;

    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 8rem;

    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

/* Resets */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-sans);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    scroll-behavior: smooth;
}

ul {
    list-style: none;
}

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

img {
    max-width: 100%;
    display: block;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* Layout & Containers */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

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

/* Typography */
h1,
h2,
h3,
h4 {
    font-weight: 600;
    line-height: 1.1;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

.hero-title {
    font-size: clamp(3rem, 6vw, 5rem);
    margin-bottom: var(--spacing-sm);
}

.hero-subtitle {
    font-size: clamp(1.25rem, 2vw, 1.75rem);
    color: var(--text-secondary);
    font-weight: 300;
    margin-bottom: var(--spacing-md);
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    margin-bottom: var(--spacing-lg);
}

.eyebrow {
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--accent-color);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    display: block;
}

.body-large {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2rem;
    border-radius: 4px;
    font-weight: 500;
    transition: var(--transition);
}

.btn-primary {
    background-color: var(--accent-color);
    color: #fff;
}

.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
}

.btn-secondary {
    background-color: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--surface-color);
    border-color: var(--text-secondary);
}

.link-arrow {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-primary);
    font-weight: 500;
}

.link-arrow:hover {
    color: var(--accent-color);
    gap: 0.75rem;
}

/* Site Header */
.site-header {
    padding: var(--spacing-md) 0;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    background: rgba(5, 7, 10, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
}

.site-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-weight: 600;
    font-size: 1.25rem;
    letter-spacing: -0.01em;
}

.nav-links {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

.nav-links a {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

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

.menu-toggle {
    display: none;
    color: var(--text-primary);
    font-size: 1.5rem;
}

/* Site Footer */
.site-footer {
    background-color: var(--surface-color);
    padding: var(--spacing-xl) 0 var(--spacing-md);
    border-top: 1px solid var(--border-color);
}

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

.footer-col h4 {
    margin-bottom: var(--spacing-md);
    font-size: 1.125rem;
}

.footer-col p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    max-width: 300px;
}

.footer-col ul {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

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

.footer-col ul a:hover {
    color: var(--text-primary);
}

.footer-bottom {
    display: flex;
    justify-content: flex-start;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-color);
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

/* Layout Utilities */
.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

/* Animations */
.fade-up {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

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

/* Cards */
.card {
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    padding: var(--spacing-md);
    border-radius: 8px;
    height: 100%;
    transition: var(--transition);
}

.card:hover {
    border-color: var(--text-secondary);
}

/* Responsive */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        /* Mobile menu logic added via JS */
    }

    .menu-toggle {
        display: block;
    }

    .grid-2,
    .grid-3,
    .footer-grid {
        grid-template-columns: 1fr;
    }

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

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

/* Light Mode Section Overrides */
.section-light {
    background-color: #ffffff;
    color: #05070a;
}

.section-light .text-secondary,
.section-light p,
.section-light li {
    color: #4a5568 !important;
}

.section-light .text-tertiary {
    color: #718096 !important;
}

.section-light h1,
.section-light h2,
.section-light h3,
.section-light h4,
.section-light h5,
.section-light h6,
.section-light .section-title,
.section-light strong {
    color: #05070a !important;
}

.section-light .card {
    background-color: #f8fafc;
    border-color: #e2e8f0;
}

.section-light .card:hover {
    border-color: #cbd5e0;
}

.section-light .btn-secondary {
    color: #05070a;
    border-color: #cbd5e0;
}

.section-light .btn-secondary:hover {
    background-color: #f1f5f9;
}

.section-light .link-arrow {
    color: #05070a;
}

.section-light .link-arrow:hover {
    color: var(--accent-color);
}