/* =============================================
   header-a.css : メインヘッダー（高級建築向け）
   ============================================= */

/* ── ベース ─────────────────────────────── */
.header-a {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-h);
  z-index: var(--z-header);
  background-color: transparent;
  border-bottom: 1px solid transparent;
  transition:
    background-color var(--t-base),
    border-color var(--t-base),
    backdrop-filter var(--t-base);
}

/* スクロール後 */
.header-a.is-scrolled {
  background-color: var(--clr-bg-header);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom-color: var(--clr-border);
}

/* ── Inner ──────────────────────────────── */
.header-a__inner {
  display: flex;
  align-items: center;
  height: 100%;
  max-width: var(--inner-width);
  margin: 0 auto;
  padding: 0 var(--inner-padding);
  gap: var(--sp-md);
}

/* ── Logo ───────────────────────────────── */
.header-a__logo {
  flex-shrink: 0;
  opacity: 0;
}

.header-a__logo-link {
  display: flex;
  flex-direction: column;
  gap: 4px;
  transition: opacity var(--t-base);
}

.header-a__logo-link:hover {
  opacity: 0.72;
}

.header-a__logo-en {
  display: block;
  font-family: var(--font-en);
  font-size: 22px;
  font-weight: 300;
  letter-spacing: 0.28em;
  color: var(--clr-white);
  line-height: 1;
}

.header-a__logo-ja {
  display: block;
  font-family: var(--font-ja);
  font-size: var(--fz-2xs);
  font-weight: 300;
  letter-spacing: 0.22em;
  color: var(--clr-gold);
  line-height: 1;
}

/* ── Nav（PC） ──────────────────────────── */
.header-a__nav {
  display: flex;
  align-items: center;
  margin-left: auto;
}

.header-a__nav-list {
  display: flex;
  align-items: center;
  gap: var(--sp-sm);
}

.header-a__nav-item {
  opacity: 0;
}

.header-a__nav-link {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  padding: var(--sp-xs) var(--sp-xs);
  position: relative;
}

.header-a__nav-link::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: 80%;
  height: 1px;
  background-color: var(--clr-gold);
  transition: transform 0.3s ease;
  transform-origin: center;
}

.header-a__nav-link:hover::after,
.header-a__nav-link.is-active::after {
  transform: translateX(-50%) scaleX(1);
}

.header-a__nav-en {
  display: block;
  font-family: var(--font-en);
  font-size: var(--fz-sm);
  font-weight: 400;
  letter-spacing: 0.18em;
  color: var(--clr-white);
  line-height: 1;
  transition: color var(--t-base);
}

.header-a__nav-link:hover .header-a__nav-en {
  color: var(--clr-gold-light);
}

.header-a__nav-ja {
  display: block;
  font-family: var(--font-ja);
  font-size: 9px;
  font-weight: 300;
  letter-spacing: 0.08em;
  color: var(--clr-text-sub);
  line-height: 1;
  transition: color var(--t-base);
}

.header-a__nav-link:hover .header-a__nav-ja {
  color: var(--clr-gold);
}

/* ── Actions ────────────────────────────── */
.header-a__actions {
  display: flex;
  align-items: center;
  gap: var(--sp-sm);
  flex-shrink: 0;
  opacity: 0;
}

/* ── CTAボタン ──────────────────────────── */
.header-a__cta-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 40px;
  padding: 0 var(--sp-md);
  font-family: var(--font-ja);
  font-size: var(--fz-xs);
  font-weight: 400;
  letter-spacing: 0.14em;
  color: var(--clr-gold);
  border: 1px solid var(--clr-gold);
  background-color: transparent;
  transition:
    background-color var(--t-base),
    color var(--t-base);
  white-space: nowrap;
}

.header-a__cta-btn:hover {
  background-color: var(--clr-gold);
  color: var(--clr-bg);
}

/* ── ハンバーガー ────────────────────────── */
.header-a__hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 6px;
  width: 40px;
  height: 40px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
  flex-shrink: 0;
}

.header-a__hamburger-line {
  display: block;
  width: 26px;
  height: 1px;
  background-color: var(--clr-white);
  transition:
    transform 0.35s ease,
    opacity 0.35s ease,
    background-color var(--t-base);
  transform-origin: center;
}

.header-a__hamburger.is-open .header-a__hamburger-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.header-a__hamburger.is-open .header-a__hamburger-line:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.header-a__hamburger.is-open .header-a__hamburger-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ── SP メニュー ─────────────────────────── */
.header-a__sp-menu {
  position: fixed;
  top: var(--header-h-sp);
  left: 0;
  width: 100%;
  height: calc(100vh - var(--header-h-sp));
  background-color: rgba(8, 8, 16, 0.98);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  z-index: var(--z-overlay);
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: var(--sp-lg) var(--inner-padding-sp);
  overflow-y: auto;
  /* GSAP制御のため非表示 */
  visibility: hidden;
  opacity: 0;
  pointer-events: none;
}

.header-a__sp-menu.is-open {
  visibility: visible;
  pointer-events: auto;
}

.header-a__sp-nav-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.header-a__sp-nav-item {
  border-bottom: 1px solid var(--clr-border-dim);
  opacity: 0;
  transform: translateY(12px);
}

.header-a__sp-nav-link {
  display: flex;
  align-items: center;
  gap: var(--sp-sm);
  padding: var(--sp-md) 0;
  transition: padding-left var(--t-base);
}

.header-a__sp-nav-link:hover {
  padding-left: var(--sp-xs);
}

.header-a__sp-nav-link .en {
  font-family: var(--font-en);
  font-size: var(--fz-xl);
  font-weight: 300;
  letter-spacing: 0.18em;
  color: var(--clr-white);
  line-height: 1;
  transition: color var(--t-base);
}

.header-a__sp-nav-link:hover .en {
  color: var(--clr-gold-light);
}

.header-a__sp-nav-link .ja {
  font-family: var(--font-ja);
  font-size: var(--fz-xs);
  font-weight: 300;
  letter-spacing: 0.1em;
  color: var(--clr-gold);
  line-height: 1;
}

/* SP CTA */
.header-a__sp-cta {
  margin-top: var(--sp-lg);
  opacity: 0;
  transform: translateY(12px);
}

.header-a__sp-cta-btn {
  display: block;
  width: 100%;
  padding: var(--sp-md) 0;
  text-align: center;
  font-family: var(--font-ja);
  font-size: var(--fz-sm);
  font-weight: 400;
  letter-spacing: 0.2em;
  color: var(--clr-bg);
  background-color: var(--clr-gold);
  transition: opacity var(--t-base);
}

.header-a__sp-cta-btn:hover {
  opacity: 0.85;
}

/* ── Responsive ─────────────────────────── */
@media (max-width: 1024px) {
  .header-a__nav {
    display: none;
  }

  .header-a__cta-btn {
    display: none;
  }

  .header-a__hamburger {
    display: flex;
  }

  .header-a {
    height: var(--header-h-sp);
  }

  .header-a__inner {
    padding: 0 var(--inner-padding-sp);
  }

  .header-a__logo-en {
    font-size: var(--fz-md);
  }
}