/* ==========================================================================
   NEUBoard — Styles
   Dark, authoritative design for board-level AI governance
   ========================================================================== */

/* --------------------------------------------------------------------------
   CSS Custom Properties (Design Tokens)
   -------------------------------------------------------------------------- */
:root {
    /* Colors */
    --color-primary: #1a1f36;
    --color-secondary: #2d3748;
    --color-accent: #b8860b;
    --color-accent-hover: #d4a017;
    --color-text-light: #f7f8fa;
    --color-text-muted: #a0aec0;
    --color-text-dark: #1a1f36;
    --color-bg-light: #ffffff;
    --color-bg-dark: #1a1f36;
    --color-border: rgba(255, 255, 255, 0.1);
    --color-border-light: rgba(26, 31, 54, 0.1);

    /* Typography */
    --font-heading: 'Playfair Display', Georgia, 'Times New Roman', serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* Font Sizes */
    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 2rem;
    --text-4xl: 2.5rem;
    --text-5xl: 3.5rem;

    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    --space-2xl: 5rem;
    --space-3xl: 8rem;

    /* Layout */
    --max-width: 800px;
    --container-padding: 1.5rem;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 300ms ease;
}

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

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

body {
    font-family: var(--font-body);
    font-size: var(--text-base);
    line-height: 1.7;
    color: var(--color-text-dark);
    background-color: var(--color-bg-dark);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* --------------------------------------------------------------------------
   Accessibility
   -------------------------------------------------------------------------- */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    padding: var(--space-sm) var(--space-md);
    background: var(--color-accent);
    color: var(--color-text-light);
    text-decoration: none;
    z-index: 1000;
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: 0;
}

/* Focus styles */
:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

/* --------------------------------------------------------------------------
   Layout
   -------------------------------------------------------------------------- */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

.section {
    padding: var(--space-3xl) 0;
}

.section--hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: var(--space-2xl) 0;
}

.section--compact {
    padding: var(--space-2xl) 0;
}

.section--dark {
    background-color: var(--color-bg-dark);
    color: var(--color-text-light);
}

.section--light {
    background-color: var(--color-bg-light);
    color: var(--color-text-dark);
}

/* --------------------------------------------------------------------------
   Typography
   -------------------------------------------------------------------------- */
h1, h2, h3 {
    font-family: var(--font-heading);
    font-weight: 600;
    line-height: 1.2;
}

.logo {
    font-size: var(--text-5xl);
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: var(--space-md);
    color: var(--color-text-light);
}

.tagline {
    font-family: var(--font-heading);
    font-size: var(--text-2xl);
    font-weight: 500;
    color: var(--color-accent);
    margin-bottom: var(--space-lg);
}

.subheading {
    font-size: var(--text-lg);
    color: var(--color-text-muted);
    max-width: 600px;
    margin: 0 auto var(--space-xl);
    line-height: 1.8;
}

.section-title {
    font-size: var(--text-3xl);
    margin-bottom: var(--space-xl);
}

.section--light .section-title {
    color: var(--color-text-dark);
}

.section--dark .section-title {
    color: var(--color-text-light);
}

/* --------------------------------------------------------------------------
   Prose (Body Text Blocks)
   -------------------------------------------------------------------------- */
.prose {
    font-size: var(--text-lg);
    line-height: 1.8;
}

.prose p {
    margin-bottom: var(--space-md);
}

.prose p:last-child {
    margin-bottom: 0;
}

.prose .lead {
    font-size: var(--text-xl);
    font-weight: 500;
    color: var(--color-accent);
    margin-bottom: var(--space-md);
}

.section--light .prose .lead {
    color: var(--color-primary);
}

.prose--small {
    font-size: var(--text-base);
    color: var(--color-text-muted);
}

/* --------------------------------------------------------------------------
   Lists
   -------------------------------------------------------------------------- */
.feature-list,
.audience-list,
.engagement-list {
    list-style: none;
    font-size: var(--text-lg);
}

.feature-list li,
.audience-list li,
.engagement-list li {
    position: relative;
    padding-left: var(--space-lg);
    margin-bottom: var(--space-md);
    line-height: 1.6;
}

.feature-list li:last-child,
.audience-list li:last-child,
.engagement-list li:last-child {
    margin-bottom: 0;
}

.feature-list li::before,
.audience-list li::before,
.engagement-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.6em;
    width: 8px;
    height: 2px;
    background-color: var(--color-accent);
}

.section--light .feature-list li::before,
.section--light .audience-list li::before,
.section--light .engagement-list li::before {
    background-color: var(--color-primary);
}

.engagement-type {
    display: block;
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */
.cta-group {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    justify-content: center;
}

.btn {
    display: inline-block;
    padding: var(--space-sm) var(--space-lg);
    font-family: var(--font-body);
    font-size: var(--text-base);
    font-weight: 500;
    text-decoration: none;
    border-radius: 4px;
    transition: all var(--transition-base);
    cursor: pointer;
    border: 2px solid transparent;
}

.btn--primary {
    background-color: var(--color-accent);
    color: var(--color-text-light);
    border-color: var(--color-accent);
}

.btn--primary:hover,
.btn--primary:focus {
    background-color: var(--color-accent-hover);
    border-color: var(--color-accent-hover);
}

.btn--secondary {
    background-color: transparent;
    color: var(--color-text-light);
    border-color: var(--color-text-muted);
}

.btn--secondary:hover,
.btn--secondary:focus {
    border-color: var(--color-text-light);
    color: var(--color-text-light);
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.footer {
    background-color: var(--color-secondary);
    padding: var(--space-xl) 0;
    text-align: center;
}

.footer-email {
    display: inline-block;
    color: var(--color-text-muted);
    text-decoration: none;
    font-size: var(--text-sm);
    margin-bottom: var(--space-sm);
    transition: color var(--transition-fast);
}

.footer-email:hover {
    color: var(--color-accent);
}

.copyright {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    opacity: 0.7;
}

/* --------------------------------------------------------------------------
   Animations (Fade-in on scroll)
   -------------------------------------------------------------------------- */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* --------------------------------------------------------------------------
   Responsive Design
   -------------------------------------------------------------------------- */
@media (max-width: 768px) {
    :root {
        --text-5xl: 2.5rem;
        --text-4xl: 2rem;
        --text-3xl: 1.75rem;
        --text-2xl: 1.25rem;
        --space-3xl: 5rem;
        --space-2xl: 3rem;
    }

    .section--hero {
        min-height: auto;
        padding: var(--space-3xl) 0;
    }

    .subheading {
        font-size: var(--text-base);
    }

    .cta-group {
        flex-direction: column;
        align-items: stretch;
    }

    .btn {
        text-align: center;
    }
}

@media (max-width: 480px) {
    :root {
        --text-5xl: 2rem;
        --text-3xl: 1.5rem;
        --container-padding: 1rem;
    }

    .prose,
    .feature-list,
    .audience-list,
    .engagement-list {
        font-size: var(--text-base);
    }
}

/* --------------------------------------------------------------------------
   Print Styles
   -------------------------------------------------------------------------- */
@media print {
    .section--dark {
        background: white;
        color: black;
    }

    .section--dark .section-title,
    .section--dark .logo {
        color: black;
    }

    .btn {
        border: 1px solid black;
    }

    .skip-link {
        display: none;
    }

    .section {
        page-break-inside: avoid;
    }
}