/* ============================================================
   Header — ロゴ左上 + ハンバーガー右上（PC/SP 共通）
   - 初期状態は透過背景・白抜きロゴ（hero overlay 上での視認性）
   - スクロール後（body.is-scrolled）でソリッド背景に切り替わる
   ============================================================ */

.site-header {
	position: fixed;
	inset: 0 0 auto 0;
	z-index: 100;
	padding-block: 1.1rem;
	pointer-events: none;
	transition: background-color var(--dur-2) var(--ease), color var(--dur-2) var(--ease), padding var(--dur-2) var(--ease);
}
.site-header__inner {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 1rem;
	width: 100%;
	max-width: var(--container);
	margin-inline: auto;
	padding-inline: var(--gutter);
}
.site-header > * { pointer-events: auto; }

/* ロゴ */
.site-header__logo {
	display: inline-flex;
	align-items: center;
	gap: 0.6rem;
	color: var(--c-on-dark);
	transition: color var(--dur-2) var(--ease);
}
.site-header__logo-img {
	width: auto;
	height: clamp(28px, 3.4vw, 36px);
	filter: brightness(0) invert(1);
	transition: filter var(--dur-2) var(--ease);
}

/* ハンバーガー */
.site-header__menu-btn {
	position: relative;
	display: inline-flex;
	align-items: center;
	gap: 0.7rem;
	padding: 0.4rem 0.6rem;
	color: var(--c-on-dark);
	font-family: var(--ff-display);
	font-size: clamp(0.7rem, 0.25vw + 0.62rem, 0.76rem);
	letter-spacing: 0.18em;
	text-transform: uppercase;
	transition: color var(--dur-2) var(--ease);
}
.site-header__menu-icon {
	display: inline-block;
	position: relative;
	width: 26px; height: 14px;
}
.site-header__menu-icon span {
	position: absolute;
	left: 0;
	display: block;
	width: 100%;
	height: 1.5px;
	background: currentColor;
	transition: transform var(--dur-2) var(--ease), opacity var(--dur-1) var(--ease), top var(--dur-2) var(--ease);
}
.site-header__menu-icon span:nth-child(1) { top: 0; }
.site-header__menu-icon span:nth-child(2) { top: 50%; transform: translateY(-50%); }
.site-header__menu-icon span:nth-child(3) { top: 100%; transform: translateY(-100%); }

.site-header__menu-text { line-height: 1; }
.site-header__menu-btn:hover { color: var(--c-brand); }

/* スクロール後の見た目（body.is-scrolled） */
body.is-scrolled .site-header {
	background: rgba(255, 255, 255, 0.94);
	backdrop-filter: saturate(140%) blur(8px);
	-webkit-backdrop-filter: saturate(140%) blur(8px);
	box-shadow: 0 1px 0 rgba(0,0,0,0.04);
	padding-block: 0.7rem;
}
body.is-scrolled .site-header__logo,
body.is-scrolled .site-header__menu-btn {
	color: var(--c-ink);
}
body.is-scrolled .site-header__logo-img {
	filter: none;
}

/* hero を持たないページは最初からソリッド扱い */
body:not(.has-hero) .site-header {
	background: rgba(255, 255, 255, 0.94);
	backdrop-filter: saturate(140%) blur(8px);
	-webkit-backdrop-filter: saturate(140%) blur(8px);
}
body:not(.has-hero) .site-header__logo,
body:not(.has-hero) .site-header__menu-btn {
	color: var(--c-ink);
}
body:not(.has-hero) .site-header__logo-img {
	filter: none;
}

/* メニューが開いている時：×アイコン化 */
body.is-nav-open .site-header__menu-icon span:nth-child(1) {
	top: 50%;
	transform: translateY(-50%) rotate(45deg);
}
body.is-nav-open .site-header__menu-icon span:nth-child(2) { opacity: 0; }
body.is-nav-open .site-header__menu-icon span:nth-child(3) {
	top: 50%;
	transform: translateY(-50%) rotate(-45deg);
}
body.is-nav-open .site-header {
	background: transparent;
	backdrop-filter: none;
	-webkit-backdrop-filter: none;
	box-shadow: none;
}
body.is-nav-open .site-header__logo,
body.is-nav-open .site-header__menu-btn {
	color: var(--c-on-dark);
}
body.is-nav-open .site-header__logo-img {
	filter: brightness(0) invert(1);
}

/* ============================================================
   Nav Overlay — フルスクリーンメニュー
   ============================================================ */
.nav-overlay {
	position: fixed;
	inset: 0;
	z-index: 90;
	display: flex;
	align-items: center;
	justify-content: center;
	background: var(--c-ink);
	color: var(--c-on-dark);
	opacity: 0;
	visibility: hidden;
	transition: opacity var(--dur-2) var(--ease), visibility 0s linear var(--dur-2);
}
body.is-nav-open .nav-overlay {
	opacity: 1;
	visibility: visible;
	transition: opacity var(--dur-2) var(--ease), visibility 0s;
}

.nav-overlay__list {
	display: flex;
	flex-direction: column;
	gap: clamp(0.6rem, 2vw, 1.4rem);
	width: 100%;
	max-width: 600px;
	padding-inline: var(--gutter);
}
.nav-overlay__list > li {
	overflow: hidden;
}
.nav-overlay__list a {
	display: flex;
	align-items: baseline;
	gap: 1.4rem;
	padding-block: 0.5rem;
	color: var(--c-on-dark);
	transform: translateY(40px);
	opacity: 0;
	transition: transform var(--dur-2) var(--ease), opacity var(--dur-2) var(--ease), color var(--dur-1) var(--ease);
}
body.is-nav-open .nav-overlay__list a {
	transform: translateY(0);
	opacity: 1;
}
/* stagger */
body.is-nav-open .nav-overlay__list > li:nth-child(1) a { transition-delay: 0.10s; }
body.is-nav-open .nav-overlay__list > li:nth-child(2) a { transition-delay: 0.16s; }
body.is-nav-open .nav-overlay__list > li:nth-child(3) a { transition-delay: 0.22s; }
body.is-nav-open .nav-overlay__list > li:nth-child(4) a { transition-delay: 0.28s; }
body.is-nav-open .nav-overlay__list > li:nth-child(5) a { transition-delay: 0.34s; }
body.is-nav-open .nav-overlay__list > li:nth-child(6) a { transition-delay: 0.40s; }
body.is-nav-open .nav-overlay__list > li:nth-child(7) a { transition-delay: 0.46s; }
body.is-nav-open .nav-overlay__list > li:nth-child(8) a { transition-delay: 0.52s; }

/* 行頭の小さな丸ドット（ホバーで横棒に伸びる） */
.nav-overlay__bullet {
	display: inline-block;
	width: 6px;
	height: 6px;
	margin-right: 1.4rem;
	background: rgba(255,255,255,0.55);
	border-radius: 50%;
	transition: width var(--dur-2) var(--ease), background var(--dur-1) var(--ease), border-radius var(--dur-2) var(--ease);
	flex-shrink: 0;
	transform: translateY(-0.35em);
}
.nav-overlay__list a:hover .nav-overlay__bullet,
.nav-overlay__list a:focus-visible .nav-overlay__bullet {
	width: 28px;
	background: var(--c-brand);
	border-radius: 1px;
}
.nav-overlay__label {
	font-family: var(--ff-display);
	/* 2026-05-06 文字サイズ縮小（クライアント指摘）: 旧 clamp(1.3rem, 3.4vw + 0.5rem, 2rem) → 新 max 1.25rem に約60%縮小 */
	font-size: clamp(0.95rem, 1.5vw + 0.4rem, 1.25rem);
	font-weight: 600;
	letter-spacing: 0.12em;
	line-height: 1.2;
	transition: transform var(--dur-1) var(--ease), color var(--dur-1) var(--ease);
}
.nav-overlay__list a:hover .nav-overlay__label,
.nav-overlay__list a:focus-visible .nav-overlay__label {
	color: var(--c-brand);
	transform: translateX(6px);
}
.nav-overlay__ext {
	margin-left: 0.6em;
	font-size: 0.55em;
	color: rgba(255,255,255,0.55);
	transform: translateY(-0.2em);
}

/* スクロールロック（メニュー開いた時） */
body.is-nav-open {
	overflow: hidden;
}