/**
 * THE HALDANKAR METHOD RESEARCH LABORATORY — GLOBAL NAVIGATION STYLES
 * Pure Dark Terminal / APCA-Compliant Header & Nav System
 */

/* --------------------------------------------------------------------------
   1. DESIGN TOKENS & CSS VARIABLES
   -------------------------------------------------------------------------- */
:root {
    --nav-bg: #000000;
    --nav-bg-alt: #09090b;
    --nav-surface: #09090b;
    --nav-surface-elevated: #121215;
    --nav-text-primary: #f4f4f5;
    --nav-text-secondary: #d4d4d8;
    --nav-text-muted: #a1a1aa;
    --nav-border: #27272a;
    --nav-border-strong: #3f3f46;
    --nav-gold: #c6a227;
    --nav-gold-hover: #d4af37;
    --nav-gold-subtle: rgba(198, 162, 39, 0.08);
    --nav-gold-border: rgba(198, 162, 39, 0.35);
    
    --nav-font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --nav-font-mono: 'JetBrains Mono', 'SF Mono', Consolas, Menlo, monospace;
    --nav-font-serif: 'Playfair Display', Georgia, Cambria, serif;
    
    --nav-height: 68px;
    --nav-max-width: 1200px;
    --nav-shadow-dropdown: none;
}

/* --------------------------------------------------------------------------
   2. UNIFIED SITE HEADER
   -------------------------------------------------------------------------- */
.site-header {
    position: sticky;
    top: 0;
    background-color: var(--nav-bg);
    border-bottom: 1px solid var(--nav-border);
    z-index: 900;
    width: 100%;
    backdrop-filter: none;
}

.site-header .header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: var(--nav-height);
    max-width: var(--nav-max-width);
    margin-left: auto;
    margin-right: auto;
    padding-left: clamp(1rem, 3vw, 2rem);
    padding-right: clamp(1rem, 3vw, 2rem);
    box-sizing: border-box;
}

/* Brand Lockup: THE HALDANKAR METHOD RESEARCH LABORATORY */
.header-brand-group {
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.header-brand-group .lab-brand {
    display: inline-flex;
    flex-direction: column;
    text-decoration: none;
    line-height: 1.15;
    user-select: none;
}

.header-brand-group .lab-brand__title {
    font-family: var(--nav-font-serif);
    font-size: 1.0625rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    color: var(--nav-text-primary);
}

.header-brand-group .lab-brand__subtitle {
    font-family: var(--nav-font-mono);
    font-size: 0.625rem;
    font-weight: 500;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--nav-gold);
}

/* Legacy lockup support during transition */
.header-brand-group .haldankar-brand {
    display: inline-flex;
    flex-direction: column;
    text-decoration: none;
    line-height: 1.15;
}

.header-brand-group .haldankar-brand__title {
    font-family: var(--nav-font-serif);
    font-size: 1.0625rem;
    font-weight: 600;
    color: var(--nav-text-primary);
}

.header-brand-group .haldankar-brand__word--gold {
    color: var(--nav-gold);
}

.header-brand-group .haldankar-brand__word--muted {
    color: var(--nav-text-primary);
}

/* --------------------------------------------------------------------------
   3. PRIMARY NAVIGATION MENU
   -------------------------------------------------------------------------- */
.header-nav {
    display: flex;
    align-items: center;
}

.nav-menu {
    display: flex;
    align-items: center;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: 1.5rem;
}

.nav-link {
    font-family: var(--nav-font-mono);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--nav-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 0.5rem 0;
    text-decoration: none;
    transition: color 0.1s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
}

.nav-link:hover {
    color: var(--nav-gold-hover);
}

.nav-link.active {
    color: var(--nav-gold);
    font-weight: 600;
    border-bottom: 2px solid var(--nav-gold);
}

/* --------------------------------------------------------------------------
   4. HEADER ACTIONS
   -------------------------------------------------------------------------- */
.header-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.header-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    font-family: var(--nav-font-mono);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--nav-text-secondary);
    background: var(--nav-surface);
    border: 1px solid var(--nav-border);
    border-radius: 2px;
    padding: 0.4rem 0.75rem;
    text-decoration: none;
    cursor: pointer;
    transition: border-color 0.1s ease, color 0.1s ease;
}

.header-btn:hover {
    border-color: var(--nav-gold);
    color: var(--nav-gold);
}

.mobile-toggle-btn {
    display: none;
    background: transparent;
    border: 1px solid var(--nav-border);
    border-radius: 2px;
    color: var(--nav-text-primary);
    font-size: 1.1rem;
    padding: 0.35rem 0.6rem;
    cursor: pointer;
}

/* --------------------------------------------------------------------------
   5. MOBILE RESPONSIVE
   -------------------------------------------------------------------------- */
@media (max-width: 900px) {
    .mobile-toggle-btn {
        display: block;
    }

    .header-nav {
        position: absolute;
        top: var(--nav-height);
        left: 0;
        right: 0;
        background: var(--nav-surface);
        border-bottom: 1px solid var(--nav-border);
        display: none;
        flex-direction: column;
        padding: 1.5rem;
    }

    .nav-menu.open, .header-nav.open {
        display: flex;
    }

    .nav-menu {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
        width: 100%;
    }

    .nav-link {
        font-size: 0.875rem;
        padding: 0.5rem 0;
        width: 100%;
    }
}