/* ============================================================
   NAV.CSS — BAB Dynamics
   Navigation bar, logo, links, mobile hamburger menu.
   States: default (top of page) · .nav-scrolled (compact)
           .nav-links.nav-open (mobile menu visible)
   JS hooks: preloader.js toggles .nav-scrolled;
             toggleMobileMenu() toggles .nav-open + aria-expanded.
   ============================================================ */

/* ── NAV BAR ────────────────────────────────────────────────── */
#main-nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: var(--z-nav);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 22px 5%;
    background: transparent;
    border-bottom: 1px solid transparent;
    transition:
        background var(--transition-base),
        border-color var(--transition-base),
        padding var(--transition-base),
        backdrop-filter var(--transition-base);
}

/* Compact state — added by JS after scrolling past hero */
#main-nav.nav-scrolled {
    padding: 14px 5%;
    background: rgba(5, 10, 20, 0.88);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
}

/* ── LOGO ───────────────────────────────────────────────────── */
.nav-logo {
    display: inline-flex;
    align-items: baseline;
    gap: 7px;
    text-decoration: none;
    user-select: none;
    line-height: 1;
}

.logo-bab {
    font-family: var(--font-display);
    font-size: 22px;
    font-weight: 900;
    letter-spacing: 2px;
    color: var(--primary);
    text-shadow: 0 0 18px var(--primary-glow);
    transition: text-shadow var(--transition-base);
}

.nav-logo:hover .logo-bab {
    text-shadow: 0 0 30px var(--primary);
}

.logo-dynamics {
    font-family: var(--font-display);
    font-size: 12px;
    font-weight: 400;
    letter-spacing: 4px;
    color: var(--text-secondary);
    text-transform: uppercase;
}

/* ── NAV LINKS (Desktop) ────────────────────────────────────── */
.nav-links {
    display: flex;
    align-items: center;
    gap: 36px;
}

.nav-links a {
    position: relative;
    font-family: var(--font-body);
    font-size: 14px;
    font-weight: 600;
    letter-spacing: 2.5px;
    text-transform: uppercase;
    color: var(--text-secondary);
    text-decoration: none;
    padding: 6px 0;
    transition: color var(--transition-base);
}

/* Animated underline */
.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0%;
    height: 1.5px;
    background: var(--primary);
    box-shadow: 0 0 8px var(--primary-glow);
    transition: width var(--transition-base);
}

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

.nav-links a:hover::after,
.nav-links a:focus-visible::after {
    width: 100%;
}

/* Active page indicator (founder.html sets this class) */
.nav-links a.nav-link-active {
    color: var(--primary);
}

.nav-links a.nav-link-active::after {
    width: 100%;
}

/* ── HAMBURGER (Mobile toggle) ──────────────────────────────── */
#menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 40px;
    height: 40px;
    padding: 8px;
    background: transparent;
    border: 1px solid var(--border-dim);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: border-color var(--transition-base);
}

#menu-toggle:hover,
#menu-toggle:focus-visible {
    border-color: var(--primary);
}

#menu-toggle span {
    display: block;
    width: 100%;
    height: 1.5px;
    background: var(--text-primary);
    border-radius: 2px;
    transition:
        transform var(--transition-base),
        opacity var(--transition-base);
}

/* Hamburger → X animation when menu is open */
#menu-toggle.menu-open span:nth-child(1) {
    transform: translateY(6.5px) rotate(45deg);
}

#menu-toggle.menu-open span:nth-child(2) {
    opacity: 0;
}

#menu-toggle.menu-open span:nth-child(3) {
    transform: translateY(-6.5px) rotate(-45deg);
}

/* ── MOBILE MENU ────────────────────────────────────────────── */
@media (max-width: 860px) {

    #menu-toggle { display: flex; }

    .nav-links {
        position: fixed;
        top: 0;
        right: 0;
        height: 100vh;
        height: 100dvh;
        width: min(78vw, 320px);
        flex-direction: column;
        justify-content: center;
        align-items: flex-start;
        gap: 8px;
        padding: 90px 40px 40px;
        background: rgba(5, 10, 20, 0.97);
        border-left: 1px solid var(--border);
        backdrop-filter: blur(24px);
        -webkit-backdrop-filter: blur(24px);
        transform: translateX(100%);
        transition: transform 0.45s cubic-bezier(0.16, 1, 0.3, 1);
        visibility: hidden;
    }

    .nav-links.nav-open {
        transform: translateX(0);
        visibility: visible;
    }

    .nav-links a {
        width: 100%;
        font-size: 17px;
        letter-spacing: 3px;
        padding: 16px 0;
        border-bottom: 1px solid var(--border-dim);
        opacity: 0;
        transform: translateX(24px);
        transition:
            opacity 0.4s ease,
            transform 0.4s cubic-bezier(0.16, 1, 0.3, 1),
            color var(--transition-base);
    }

    /* Staggered link entrance when menu opens */
    .nav-links.nav-open a {
        opacity: 1;
        transform: translateX(0);
    }

    .nav-links.nav-open a:nth-child(1) { transition-delay: 0.06s; }
    .nav-links.nav-open a:nth-child(2) { transition-delay: 0.12s; }
    .nav-links.nav-open a:nth-child(3) { transition-delay: 0.18s; }
    .nav-links.nav-open a:nth-child(4) { transition-delay: 0.24s; }
    .nav-links.nav-open a:nth-child(5) { transition-delay: 0.30s; }

    /* Underline animation off in mobile drawer — full-width borders instead */
    .nav-links a::after { display: none; }

}

/* ── MOBILE MENU BACKDROP ───────────────────────────────────── */
.nav-backdrop {
    position: fixed;
    inset: 0;
    z-index: calc(var(--z-nav) - 1);
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(3px);
    opacity: 0;
    visibility: hidden;
    transition:
        opacity var(--transition-base),
        visibility var(--transition-base);
}

.nav-backdrop.backdrop-visible {
    opacity: 1;
    visibility: visible;
}

/* ── REDUCED MOTION ─────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {

    .nav-links,
    .nav-links a,
    #menu-toggle span {
        transition: none;
    }

}