/* =====================================================
   header.css
   固定ヘッダー・ロゴ・ナビ・言語スイッチャー・
   ハンバーガー・モバイルナビ
   ===================================================== */

#header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--header-h);
  z-index: 1000;
  overflow: hidden;
  /* iOS Safariでfixedがtransformにブロックされないよう無効化 */
  -webkit-transform: none;
  transform: none;
  transition: background .4s ease, backdrop-filter .4s ease, box-shadow .4s ease;
}
#header.scrolled {
  background: rgba(11,11,15,.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 1px 0 rgba(200,162,75,.12);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  gap: 1.5rem;
}

/* ─── Nav links ─── */
.nav-links {
  display: flex;
  align-items: center;
  gap: clamp(.75rem, 2vw, 2rem);
  list-style: none;
}
.nav-links a {
  font-size: .78rem;
  font-weight: 400;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: rgba(255,255,255,.75);
  transition: color .2s;
  padding: .25rem 0;
  position: relative;
}
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px; left: 0;
  width: 0; height: 1px;
  background: var(--accent);
  transition: width .3s var(--ease-out);
}
.nav-links a:hover            { color: var(--white); }
.nav-links a:hover::after     { width: 100%; }

/* ─── Language switcher ─── */
.lang-switcher {
  display: flex;
  align-items: center;
  gap: .25rem;
}
.lang-btn {
  font-size: .7rem;
  font-weight: 500;
  letter-spacing: .08em;
  color: rgba(255,255,255,.5);
  padding: .3rem .45rem;
  border-radius: 2px;
  transition: all .2s;
  cursor: pointer;
  border: none;
  background: none;
  font-family: inherit;
}
.lang-btn:hover,
.lang-btn.active { color: var(--accent); }
.lang-btn.active { background: rgba(200,162,75,.12); }

/* ─── Hamburger ─── */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: .5rem;
  cursor: pointer;
  border: none;
  background: none;
  flex-shrink: 0;
}
.hamburger span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--white);
  transition: all .3s;
}
.hamburger.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* ─── Mobile nav ─── */
.mobile-nav {
  display: none;
  position: fixed;
  top: var(--header-h); left: 0; right: 0;
  background: rgba(11,11,15,.97);
  backdrop-filter: blur(20px);
  padding: 2rem;
  z-index: 999;
  flex-direction: column;
  gap: 1.5rem;
  border-top: 1px solid rgba(200,162,75,.15);
}
.mobile-nav.open { display: flex; }
.mobile-nav a {
  font-size: .9rem;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: rgba(255,255,255,.75);
  padding: .5rem 0;
  border-bottom: 1px solid rgba(255,255,255,.06);
  transition: color .2s;
}
.mobile-nav a:hover { color: var(--accent); }

.lang-btn {
  display: inline-flex;
  align-items: center;
  gap: .25rem;
  white-space: nowrap;
}