/*
 * Location  : assets/css/nav.css
 * File      : nav.css
 * Function  : Navigation – transparent-over-hero, sticky on scroll,
 *             adapts to zone-dark / zone-light context, mobile hamburger
 * Version   : 2.1.0
 * Generated : 2026-03-17
 * Changelog :
 *   1.0.0 (2026-03-17) – Initial release (dark-only nav)
 *   2.0.0 (2026-03-17) – Transparent over hero, scrolled state adaptation,
 *                         zone-adaptive link colours, updated token references
 */

/* ══════════════════════════════════════════════════════════
   TOP BAR
══════════════════════════════════════════════════════════ */
.topbar {
  background: rgba(0,0,0,.92);
  padding: .45rem 0;
  font-size: var(--fs-xs);
  border-bottom: 1px solid rgba(255,255,255,.06);
  position: relative;
  z-index: 1001;
}
.topbar__inner {
  display: flex; align-items: center;
  justify-content: space-between;
  flex-wrap: wrap; gap: .5rem;
}
.topbar__contacts {
  display: flex; align-items: center;
  gap: var(--sp-md); flex-wrap: wrap;
}
.topbar__contact {
  display: inline-flex; align-items: center; gap: .35rem;
  color: rgba(255,255,255,.55);
  text-decoration: none;
  transition: color var(--fast);
  white-space: nowrap;
}
.topbar__contact:hover { color: var(--clr-accent); }
.topbar__contact i { color: var(--clr-accent); font-size: .7rem; }

.topbar__social { display: flex; align-items: center; gap: .6rem; }
.topbar__social a {
  color: rgba(255,255,255,.45);
  font-size: 1rem; text-decoration: none;
  display: flex; align-items: center;
  transition: color var(--fast);
}
.topbar__social a:hover { color: var(--clr-accent); }

/* ══════════════════════════════════════════════════════════
   MAIN NAVIGATION
══════════════════════════════════════════════════════════ */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  /* Start transparent – blends with hero photo */
  background: transparent;
  transition:
    background var(--base) var(--ease),
    box-shadow  var(--base) var(--ease),
    backdrop-filter var(--base) var(--ease);
}

/* Once user scrolls past hero → solid dark bg */
.site-nav.scrolled {
  background: rgba(8,12,20,.96);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 4px 32px rgba(0,0,0,.55);
  border-bottom: 1px solid rgba(30,42,66,.6);
}

/* Thin accent line at bottom when scrolled */
.site-nav.scrolled::after {
  content: '';
  position: absolute; bottom: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, var(--clr-accent), var(--clr-violet), transparent 80%);
}

.site-nav__inner {
  display: flex; align-items: center;
  justify-content: space-between;
  height: 68px;
}

/* ── Logo ─────────────────────────────────────────────── */
.site-nav__logo {
  display: flex; align-items: center;
  text-decoration: none; flex-shrink: 0;
}
/* The .logo-dark class on logo-wrapper handles white fill via CSS in main.css */
.site-nav__logo .logo-wrapper { width: 160px; }
.site-nav__logo svg { width: 100%; height: auto; }
.site-nav__logo:hover .logo-wrapper { opacity: .85; }

/* ── Nav Links ────────────────────────────────────────── */
.site-nav__links {
  display: flex; align-items: center;
  gap: .2rem; list-style: none;
}

.site-nav__link {
  display: inline-flex; align-items: center;
  padding: .5rem 1rem;
  font-family: var(--font-display);
  font-size: 1rem; letter-spacing: .06em;
  color: rgba(255,255,255,.7);
  text-decoration: none;
  border-radius: var(--r-sm);
  position: relative;
  transition: color var(--fast), background var(--fast);
}
/* Underline accent */
.site-nav__link::after {
  content: '';
  position: absolute; bottom: 4px; left: 1rem; right: 1rem; height: 2px;
  background: var(--clr-accent);
  transform: scaleX(0); transform-origin: left;
  transition: transform var(--base) var(--ease-out);
  border-radius: 2px;
}
.site-nav__link:hover,
.site-nav__link[aria-current="page"] { color: #fff; }
.site-nav__link:hover::after,
.site-nav__link[aria-current="page"]::after { transform: scaleX(1); }

/* CTA button in nav */
.site-nav__cta {
  margin-left: var(--sp-sm);
  padding: .5rem 1.25rem !important;
  font-size: var(--fs-sm) !important;
}

/* ── Mobile Toggle ────────────────────────────────────── */
.nav-toggle {
  display: none;
  flex-direction: column; justify-content: center; align-items: center;
  gap: 5px;
  width: 44px; height: 44px;
  background: none;
  border: 1.5px solid rgba(255,255,255,.25);
  border-radius: var(--r-sm); cursor: pointer; padding: 0;
  transition: border-color var(--fast);
}
.nav-toggle:hover { border-color: var(--clr-accent); }
.nav-toggle span {
  display: block; width: 22px; height: 2px;
  background: #fff; border-radius: 2px;
  transition: transform var(--base) var(--ease), opacity var(--base);
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ══════════════════════════════════════════════════════════
   RESPONSIVE / MOBILE MENU
══════════════════════════════════════════════════════════ */
@media (max-width: 900px) {
  .nav-toggle { display: flex; }

  .site-nav__links {
    position: fixed;
    top: 0; right: 0; bottom: 0;
    width: min(320px, 85vw);
    flex-direction: column; align-items: flex-start;
    gap: 0;
    background: var(--zone-dark-2);
    border-left: 1px solid var(--zone-dark-border);
    padding: 5rem 2rem 2rem;
    transform: translateX(100%);
    transition: transform var(--slow) var(--ease-out);
    z-index: 999;
    overflow-y: auto;
  }
  .site-nav__links.is-open {
    transform: translateX(0);
    box-shadow: -12px 0 40px rgba(0,0,0,.6);
  }
  .site-nav__link {
    font-size: var(--fs-xl);
    padding: .75rem 0; width: 100%;
    border-bottom: 1px solid var(--zone-dark-border);
    color: rgba(255,255,255,.75);
  }
  .site-nav__link::after { display: none; }
  .site-nav__cta { margin-left: 0; margin-top: var(--sp-md); }

  /* Mobile menu backdrop */
  .site-nav__backdrop {
    display: none;
    position: fixed; inset: 0; z-index: 998;
    background: rgba(0,0,0,.5);
    backdrop-filter: blur(4px);
  }
  .site-nav__backdrop.is-open { display: block; }
}

@media (max-width: 600px) {
  .topbar__contacts { gap: var(--sp-sm); }
  .topbar__contact span { display: none; }  /* hide label, show icon only */
  .topbar__contact i { font-size: .85rem; }
}