@use "variables" as *;

// ---------------------------------------------------------------------------
// Fixed header
//   > 1024 : inline PC nav (links + SNS)
//   <=1024 : hamburger + fullscreen overlay (tablet & SP)
// ---------------------------------------------------------------------------

// Offset page content for the fixed header + keep in-page anchors visible.
body {
	padding-top: $header-h-pc;

	@include sp {
		padding-top: $header-h-sp;
	}
}

html {
	scroll-padding-top: $header-h-pc;

	@include sp {
		scroll-padding-top: $header-h-sp;
	}
}

// Lock scroll while the overlay is open.
body.is-nav-open {
	overflow: hidden;
}

.site-header {
	position: fixed;
	inset: 0 0 auto;
	z-index: $z-header;
	height: $header-h-pc;
	background: rgba(255, 255, 255, 0.9); // 90% white (design)

	@include sp {
		height: $header-h-sp;
	}
}

// Pass the header height down the gutter layer so the flex row can center.
.site-header > .inner {
	height: 100%;
}

.site-header__inner {
	display: flex;
	align-items: center;
	justify-content: space-between;
	column-gap: rem(40); // breathing room between logo and nav
	height: 100%;
}

.site-header__logo {
	position: relative;
	z-index: 1; // overlay sits ABOVE the logo when open

	a {
		display: block;
		transition: opacity 0.3s;

		&:hover {
			opacity: 0.6; // hover -> semi-transparent
		}
	}

	img {
		display: block;
		width: rem(180);
		height: auto;
	}

	@include sp {
		img {
			width: auto;
			height: rem(40); // SP logo 103x40
		}
	}
}

// ---------------------------------------------------------------------------
// Global nav — PC inline row.
// ---------------------------------------------------------------------------
.gnav {
	display: flex;
	align-items: center;
	gap: rem(24);
}

.gnav__list {
	display: flex;
	align-items: center;
	gap: rem(28);
}

.gnav__link {
	display: flex;
	flex-direction: column;
	align-items: center;
	gap: rem(10); // JP / EN gap
	text-decoration: none;
	transition: opacity 0.3s;

	&:hover {
		text-decoration: none;
		opacity: 0.6;
	}
}

.gnav__ja {
	font-family: $font-serif;
	font-weight: 700;
	font-size: rem(16);
	color: $color-text; // design: black
	line-height: 1;
}

.gnav__en {
	font-family: $font-sans;
	font-weight: 400;
	font-size: rem(12);
	color: $color-green;
	line-height: 1;
}

.gnav__sns {
	display: flex;
	align-items: center;
	gap: rem(20);

	img {
		display: block;
		width: rem(40);
		height: rem(40);
	}
}

// ---------------------------------------------------------------------------
// Hamburger — visible <=1024. Bars 40 / 30 / 20 (design), 3px, 10px apart.
// ---------------------------------------------------------------------------
.hamburger {
	display: none;
	flex-direction: column;
	align-items: flex-start;
	gap: rem(7);
	position: relative;
	z-index: 3; // above the overlay so it stays tappable (becomes the close X)
	padding: rem(4) 0;
	background: none;
	border: 0;
	cursor: pointer;

	@include tab {
		display: flex;
	}
}

.hamburger__box {
	position: relative;
	display: block;
	width: rem(40);
	height: rem(23); // bars at 0 / 10 / 20 + 3px
}

.hamburger__bar {
	position: absolute;
	left: 0;
	height: rem(3);
	background: $color-green;
	transition: width 0.25s, top 0.25s, transform 0.25s, opacity 0.25s;

	&--1 {
		top: 0;
		width: rem(40);
	}

	&--2 {
		top: rem(10);
		width: rem(30);
	}

	&--3 {
		top: rem(20);
		width: rem(20);
	}
}

.hamburger__label {
	font-family: $font-serif;
	font-weight: 700;
	font-size: rem(11);
	letter-spacing: 0.04em;
	text-transform: uppercase;
	color: $color-green;
	line-height: 1;
}

// Hamburger -> X when open (bars equalize and cross at the middle).
.is-nav-open .hamburger__bar {
	&--1 {
		top: rem(10);
		width: rem(40);
		transform: rotate(45deg);
	}

	&--2 {
		opacity: 0;
	}

	&--3 {
		top: rem(10);
		width: rem(40);
		transform: rotate(-45deg);
	}
}

// ---------------------------------------------------------------------------
// Overlay behaviour  (<=1024)
//   z-order within the header stacking context: logo(1) < overlay(2) < ham(3)
//   Scroll-safe: `safe center` falls back to top-align when the viewport is
//   too short, so the top never gets clipped; overflow-y allows scrolling.
// ---------------------------------------------------------------------------
@include tab {
	.gnav {
		position: fixed;
		inset: 0;
		z-index: 2;
		flex-direction: column;
		align-items: center;
		justify-content: center;
		justify-content: safe center;
		gap: rem(48);
		padding: calc(#{$header-h-pc} + #{rem(20)}) rem(30) rem(40);
		background: $color-white; // solid white
		overflow-y: auto;
		overscroll-behavior: contain;

		// closed state
		opacity: 0;
		visibility: hidden;
		transform: translateY(rem(-16));
		transition: opacity 0.3s, transform 0.3s, visibility 0.3s;
	}

	.is-nav-open .gnav {
		opacity: 1;
		visibility: visible;
		transform: none;
	}

	.gnav__list {
		flex-direction: column;
		gap: rem(36);
	}

	.gnav__link {
		gap: rem(8);
	}

	.gnav__ja {
		font-size: rem(22);
	}

	.gnav__en {
		font-size: rem(13);
	}

	.gnav__sns {
		gap: rem(28);

		img {
			width: rem(48);
			height: rem(48);
		}
	}
}

@include sp {
	.gnav {
		padding: calc(#{$header-h-sp} + #{rem(20)}) rem(20) rem(40);
	}

	.gnav__sns img {
		width: rem(44);
		height: rem(44);
	}
}