/* ═══════════════════════════════════════════════
   header.css — Fixed navigation header
═══════════════════════════════════════════════ */

#site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.75rem var(--space-lg);
  transition: padding 0.4s, background 0.4s, border-color 0.4s;
  border-bottom: 0.5px solid transparent;
}

#site-header.scrolled {
  padding: 1.1rem var(--space-lg);
  background: rgba(248, 246, 242, 0.94);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-color: var(--kinucha);
}

/* ── Logo ── */
.site-logo {
  font-family: var(--ff-serif-en);
  font-size: 1.55rem;
  font-weight: 300;
  letter-spacing: 0.32em;
  color: var(--washi);
  text-decoration: none;
  transition: color 0.3s;
  line-height: 1;
}
#site-header.scrolled .site-logo {
  color: var(--lila-deep);
}

.site-logo sub {
  display: block;
  font-size: 0.5rem;
  letter-spacing: 0.4em;
  color: rgba(248, 246, 242, 0.5);
  font-family: var(--ff-sans-jp);
  margin-top: 4px;
  font-weight: 300;
  vertical-align: baseline;
  transition: color 0.3s;
}
#site-header.scrolled .site-logo sub {
  color: var(--nenokuchi);
}

/* ── Desktop nav ── */
#site-nav ul {
  list-style: none;
  display: flex;
  gap: 2.2rem;
}

#site-nav a {
  font-size: 0.65rem;
  letter-spacing: 0.22em;
  color: rgba(248, 246, 242, 0.75);
  text-decoration: none;
  transition: color 0.25s;
}
#site-header.scrolled #site-nav a {
  color: var(--sumi-2);
}
#site-nav a:hover {
  color: var(--washi) !important;
}
#site-header.scrolled #site-nav a:hover {
  color: var(--lila-deep) !important;
}

/* ── Contact CTA ── */
.nav-contact {
  font-size: 0.6rem;
  letter-spacing: 0.22em;
  padding: 0.45rem 1.2rem;
  border: 0.5px solid rgba(248, 246, 242, 0.45);
  color: rgba(248, 246, 242, 0.75);
  text-decoration: none;
  transition: all 0.25s;
  white-space: nowrap;
}
#site-header.scrolled .nav-contact {
  border-color: var(--lila-mid);
  color: var(--lila-mid);
}
.nav-contact:hover {
  background: rgba(248, 246, 242, 0.15);
  color: var(--washi) !important;
  border-color: rgba(248, 246, 242, 0.6) !important;
}
#site-header.scrolled .nav-contact:hover {
  background: var(--lila-deep);
  color: var(--washi) !important;
  border-color: var(--lila-deep) !important;
}

/* ── Desktop nav gap adjustment for lang switcher ── */
#site-header {
  gap: 1.5rem;
}
.nav-hamburger {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 24px;
  height: 16px;
  padding: 0;
  z-index: 210;
}
.nav-hamburger span {
  display: block;
  width: 100%;
  height: 0.5px;
  background: var(--washi);
  transition: background 0.3s, transform 0.3s, opacity 0.3s;
  transform-origin: center;
}
#site-header.scrolled .nav-hamburger span {
  background: var(--lila-deep);
}

/* Open state */
.nav-hamburger.is-open span:nth-child(1) {
  transform: translateY(7.5px) rotate(45deg);
}
.nav-hamburger.is-open span:nth-child(2) {
  opacity: 0;
}
.nav-hamburger.is-open span:nth-child(3) {
  transform: translateY(-7.5px) rotate(-45deg);
}

/* ── Mobile menu overlay ── */
.mobile-menu {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 190;
  background: rgba(29, 22, 40, 0.97);
  flex-direction: column;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.35s;
}
.mobile-menu.is-open {
  opacity: 1;
  pointer-events: auto;
}
.mobile-menu nav ul {
  list-style: none;
  text-align: center;
}
.mobile-menu nav li {
  margin-bottom: 2rem;
}
.mobile-menu a {
  font-family: var(--ff-serif-jp);
  font-size: 1.4rem;
  font-weight: 200;
  letter-spacing: 0.18em;
  color: rgba(248, 246, 242, 0.8);
  text-decoration: none;
  transition: color 0.2s;
}
.mobile-menu a:hover {
  color: var(--lila-pale);
}