/* ================================================================
   NAV — Fixed Header with Scroll Effects
   ================================================================ */

.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  padding: 1.8rem var(--gutter);
  transition: background 0.6s var(--ease-out),
              padding 0.4s var(--ease-out),
              transform 0.5s var(--ease-out);
}
.header.is-scrolled {
  background: rgba(10, 10, 10, 0.8);
  backdrop-filter: blur(24px) saturate(1.2);
  -webkit-backdrop-filter: blur(24px) saturate(1.2);
  padding: 1rem var(--gutter);
}
.header.is-hidden {
  transform: translateY(-100%);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1440px;
  margin: 0 auto;
}

.nav__logo {
  font-family: var(--serif);
  font-size: 1rem;
  font-weight: 400;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-light);
  transition: opacity 0.3s;
}
.nav__logo:hover { opacity: 0.7; }

.nav__links {
  display: flex;
  gap: 2.5rem;
}

.nav__link {
  font-family: var(--sans);
  font-size: 0.68rem;
  font-weight: 300;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-muted);
  transition: color 0.3s;
  position: relative;
  padding: 0.2em 0;
}
.nav__link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--gold);
  transition: width 0.5s var(--ease-out);
}
.nav__link:hover { color: var(--text-light); }
.nav__link:hover::after { width: 100%; }
.nav__link--active { color: var(--text-light); }
.nav__link--active::after { width: 100%; }

.nav__cta {
  font-family: var(--sans);
  font-size: 0.62rem;
  font-weight: 400;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--dark);
  background: var(--ivory);
  padding: 0.65rem 2rem;
  transition: background 0.4s var(--ease-out),
              color 0.3s,
              transform 0.3s var(--ease-out);
}
.nav__cta:hover {
  background: var(--gold);
  transform: translateY(-2px);
}