/* ═══════════════════════════════════════════════════════════
   TIANX STUDIO — Navigation
   ═══════════════════════════════════════════════════════════ */

/* ─── MAIN NAV ─────────────────────────────────────────── */

.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: var(--z-nav);
  padding: 1.5rem var(--container-pad);
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition:
    background var(--transition),
    backdrop-filter var(--transition),
    padding var(--transition);
}

.nav.scrolled {
  background: rgba(247, 248, 250, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  padding: 1rem var(--container-pad);
  box-shadow: 0 1px 0 var(--border);
}

/* Dark nav for dark hero pages */
.nav--dark.scrolled {
  background: rgba(12, 18, 34, 0.92);
  box-shadow: 0 1px 0 var(--border-light);
}

/* ─── LOGO ─────────────────────────────────────────────── */

.nav__logo {
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-primary);
  transition: color var(--duration-sm);
}

.nav__logo span {
  color: var(--accent);
}

.nav--dark .nav__logo {
  color: var(--text-inverse);
}

/* ─── NAV LINKS ────────────────────────────────────────── */

.nav__links {
  display: flex;
  gap: 2.5rem;
  align-items: center;
}

.nav__link {
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--text-muted);
  transition: color var(--duration-sm);
  position: relative;
}

.nav__link:hover {
  color: var(--text-primary);
}

.nav__link.active {
  color: var(--text-primary);
}

.nav__link.active::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 100%;
  height: 1px;
  background: var(--accent);
}

/* Dark variant */
.nav--dark .nav__link {
  color: rgba(255,255,255,0.45);
}
.nav--dark .nav__link:hover {
  color: rgba(255,255,255,0.85);
}
.nav--dark .nav__link.active {
  color: #fff;
}

/* ─── NAV RIGHT (CTA + LANG) ──────────────────────────── */

.nav__right {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.nav__cta {
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  padding: 10px 24px;
  border: 1px solid var(--primary);
  color: var(--primary);
  border-radius: var(--radius-xs);
  transition: all var(--duration-sm);
}

.nav__cta:hover {
  background: var(--primary);
  color: var(--surface);
}

.nav--dark .nav__cta {
  border-color: var(--border-light-strong);
  color: rgba(255,255,255,0.7);
}
.nav--dark .nav__cta:hover {
  background: rgba(255,255,255,0.1);
  color: #fff;
}

/* ─── LANGUAGE TOGGLE ──────────────────────────────────── */

.lang-toggle {
  display: flex;
  align-items: center;
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  overflow: hidden;
}

.lang-toggle__btn {
  padding: 6px 12px;
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  transition: all var(--duration-sm);
  cursor: pointer;
  background: transparent;
}

.lang-toggle__btn.active {
  background: var(--primary);
  color: var(--surface);
}

.lang-toggle__btn:hover:not(.active) {
  color: var(--text-primary);
}

.nav--dark .lang-toggle {
  border-color: var(--border-light);
}
.nav--dark .lang-toggle__btn {
  color: rgba(255,255,255,0.4);
}
.nav--dark .lang-toggle__btn.active {
  background: rgba(255,255,255,0.15);
  color: #fff;
}
.nav--dark .lang-toggle__btn:hover:not(.active) {
  color: rgba(255,255,255,0.7);
}

/* ─── MOBILE DRAWER ────────────────────────────────────── */

.nav__burger {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 24px;
  cursor: pointer;
  padding: 4px 0;
}

.nav__burger span {
  display: block;
  width: 100%;
  height: 1.5px;
  background: var(--text-primary);
  transition: all var(--duration-sm) var(--ease);
}

.nav--dark .nav__burger span {
  background: var(--text-inverse);
}

.nav__burger.open span:nth-child(1) {
  transform: rotate(45deg) translate(4px, 5px);
}
.nav__burger.open span:nth-child(2) {
  opacity: 0;
}
.nav__burger.open span:nth-child(3) {
  transform: rotate(-45deg) translate(4px, -5px);
}

.nav__drawer {
  display: none;
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  z-index: calc(var(--z-nav) - 1);
  background: var(--surface);
  padding: 6rem var(--container-pad) var(--space-lg);
  flex-direction: column;
  gap: var(--space-md);
  opacity: 0;
  transform: translateY(-10px);
  transition: all var(--duration-md) var(--ease);
}

.nav__drawer.open {
  display: flex;
  opacity: 1;
  transform: translateY(0);
}

.nav--dark .nav__drawer {
  background: var(--surface-dark);
}

.nav__drawer .nav__link {
  font-size: 1.2rem;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
}

.nav__drawer .nav__link:hover,
.nav__drawer .nav__link.active {
  color: var(--text-primary);
}

.nav--dark .nav__drawer .nav__link {
  color: rgba(255,255,255,0.5);
}
.nav--dark .nav__drawer .nav__link:hover {
  color: #fff;
}

.nav__drawer .lang-toggle {
  margin-top: auto;
}