/* ============================================
   Navigation
   ============================================ */

.site-header {
	position: fixed;
	top: 0;
	left: 0;
	right: 0;
	z-index: var(--z-sticky);
	height: var(--header-height);
	display: flex;
	align-items: center;
	background-color: transparent;
	transition: background-color var(--transition-base), box-shadow var(--transition-base);
}

/* Header gains elevated style on scroll */
.site-header.is-scrolled {
	background-color: rgba(10, 22, 40, 0.92);
	backdrop-filter: blur(12px);
	-webkit-backdrop-filter: blur(12px);
	box-shadow: 0 1px 0 var(--color-border), var(--glow-sm);
}

.site-header__inner {
	display: flex;
	align-items: center;
	justify-content: space-between;
	width: 100%;
	max-width: var(--container-max);
	margin-inline: auto;
	padding-inline: var(--space-6);
}

@media (min-width: 768px) {
	.site-header__inner {
		padding-inline: var(--space-8);
	}
}

@media (min-width: 1024px) {
	.site-header__inner {
		padding-inline: var(--space-12);
	}
}


/* ── Logo ────────────────────────────────── */

.site-logo {
	display: flex;
	flex-direction: column;
	line-height: 1;
	text-decoration: none;
}

.site-logo__wordmark {
	font-family: var(--font-display);
	font-size: var(--text-2xl);
	font-weight: var(--weight-bold);
	letter-spacing: 0.08em;
	color: var(--color-cherenkov);
	text-shadow: var(--glow-text-sm);
	transition: text-shadow var(--transition-fast);
}

.site-logo:hover .site-logo__wordmark,
.site-logo:focus .site-logo__wordmark {
	text-shadow: var(--glow-text-md);
}

.site-logo__sub {
	font-family: var(--font-body);
	font-size: var(--text-xs);
	font-weight: var(--weight-light);
	letter-spacing: 0.18em;
	text-transform: uppercase;
	color: var(--color-text-secondary);
}


/* ── Nav menu ────────────────────────────── */

.site-nav {
	display: none;
	gap: var(--space-8);
}

@media (min-width: 768px) {
	.site-nav {
		display: flex;
		align-items: center;
	}
}

.site-nav__link {
	font-family: var(--font-body);
	font-size: var(--text-sm);
	font-weight: var(--weight-medium);
	letter-spacing: 0.06em;
	text-transform: uppercase;
	color: var(--color-text-secondary);
	transition: color var(--transition-fast);
	position: relative;
}

.site-nav__link::after {
	content: '';
	position: absolute;
	bottom: -4px;
	left: 0;
	width: 0;
	height: 1px;
	background-color: var(--color-cherenkov);
	transition: width var(--transition-base);
}

.site-nav__link:hover,
.site-nav__link:focus,
.site-nav__link.is-active {
	color: var(--color-cherenkov);
}

.site-nav__link.is-active::after,
.site-nav__link:hover::after {
	width: 100%;
}


/* ── Hamburger (mobile) ──────────────────── */

.nav-toggle {
	display: flex;
	flex-direction: column;
	justify-content: center;
	gap: 5px;
	width: 40px;
	height: 40px;
	padding: var(--space-2);
	color: var(--color-text-primary);
	border: 1px solid var(--color-border);
	border-radius: var(--radius-md);
	transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

@media (min-width: 768px) {
	.nav-toggle {
		display: none;
	}
}

.nav-toggle:hover,
.nav-toggle:focus {
	border-color: var(--color-border-strong);
	box-shadow: var(--glow-sm);
}

.nav-toggle__bar {
	display: block;
	width: 100%;
	height: 2px;
	background-color: var(--color-cherenkov);
	border-radius: var(--radius-full);
	transition: transform var(--transition-base), opacity var(--transition-fast);
}

/* Animate hamburger → X when open */
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) {
	transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) {
	opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) {
	transform: translateY(-7px) rotate(-45deg);
}


/* ── Mobile nav menu ─────────────────────── */

.mobile-nav {
	display: none;
	position: fixed;
	top: var(--header-height);
	left: 0;
	right: 0;
	z-index: calc(var(--z-sticky) - 1);
	padding: var(--space-6);
	background-color: rgba(10, 22, 40, 0.97);
	backdrop-filter: blur(16px);
	-webkit-backdrop-filter: blur(16px);
	border-bottom: 1px solid var(--color-border);
	flex-direction: column;
	gap: var(--space-2);
}

.mobile-nav.is-open {
	display: flex;
}

@media (min-width: 768px) {
	.mobile-nav {
		display: none !important;
	}
}

.mobile-nav__link {
	display: block;
	padding: var(--space-3) var(--space-4);
	font-family: var(--font-display);
	font-size: var(--text-xl);
	font-weight: var(--weight-semibold);
	letter-spacing: 0.06em;
	color: var(--color-text-secondary);
	border-radius: var(--radius-md);
	transition: color var(--transition-fast), background-color var(--transition-fast);
}

.mobile-nav__link:hover,
.mobile-nav__link:focus,
.mobile-nav__link.is-active {
	color: var(--color-cherenkov);
	background-color: rgba(0, 223, 255, 0.05);
}