.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  padding-inline: var(--section-pad-x);
  background: color-mix(in srgb, var(--color-bg) 88%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid color-mix(in srgb, var(--color-line) 70%, transparent);
  transition: background-color var(--duration) var(--ease-out), box-shadow var(--duration) var(--ease-out);
}

.site-header.is-scrolled {
  background: color-mix(in srgb, var(--color-bg-elevated) 94%, transparent);
  box-shadow: 0 1px 0 var(--color-line);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  height: 100%;
  width: min(100%, var(--content-max));
  margin-inline: auto;
}

.site-logo {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  flex-shrink: 1;
  min-width: 0;
  max-width: min(100%, 17.5rem);
  perspective: 640px;
}

.site-logo__icon {
  width: 2.2rem;
  height: 2.2rem;
  object-fit: contain;
  flex-shrink: 0;
  transform-style: preserve-3d;
  backface-visibility: visible;
  animation: logo-spin-y 10s linear infinite;
  will-change: transform;
}

@keyframes logo-spin-y {
  from {
    transform: rotateY(0deg);
  }
  to {
    transform: rotateY(360deg);
  }
}

@media (prefers-reduced-motion: reduce) {
  .site-logo__icon {
    animation: none;
  }
}

.site-logo--header .site-logo__text {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.18rem;
  width: max-content;
  max-width: 100%;
}

.site-logo--header .site-logo__name {
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 2.4vw, 1.28rem);
  font-weight: 700;
  letter-spacing: 0.015em;
  line-height: 1.05;
  text-transform: uppercase;
  color: var(--color-logo);
  white-space: nowrap;
}

.site-logo--header .site-logo__tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  color: color-mix(in srgb, var(--color-logo) 72%, white);
  line-height: 1.2;
  white-space: nowrap;
  transform-origin: left center;
}

.site-logo__name {
  font-family: var(--font-display);
  font-size: 1.45rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1;
  text-transform: uppercase;
  color: var(--color-ink);
}

.site-logo__tag {
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--color-muted);
  line-height: 1.2;
}

@media (min-width: 900px) {
  .site-logo {
    max-width: 22rem;
    flex-shrink: 0;
  }

  .site-logo--header .site-logo__icon {
    width: 2.45rem;
    height: 2.45rem;
  }

  .site-logo--header .site-logo__name {
    font-size: 1.32rem;
  }

  .site-logo--header .site-logo__tag {
    font-size: 0.8rem;
  }
}

.site-nav {
  display: none;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(0.35rem, 1.5vw, 1.25rem);
}

.site-nav__link {
  position: relative;
  padding: 0.4rem 0.55rem;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-ink-soft);
  transition: color var(--duration-fast) var(--ease-out);
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0.55rem;
  right: 0.55rem;
  bottom: 0.15rem;
  height: 1.5px;
  background: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--duration) var(--ease-out);
}

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

.site-nav__link.is-active::after,
.site-nav__link:hover::after {
  transform: scaleX(1);
}

.nav-toggle {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 2.75rem;
  height: 2.75rem;
  padding: 0.55rem;
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  background: var(--color-bg-elevated);
}

.nav-toggle__bar {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--color-ink);
  transition:
    transform var(--duration) var(--ease-out),
    opacity var(--duration-fast) var(--ease-out);
}

.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);
}

.site-nav--mobile {
  display: none;
  position: absolute;
  left: 0;
  right: 0;
  top: var(--header-h);
  padding: var(--space-md) var(--section-pad-x) var(--space-lg);
  background: var(--color-bg-elevated);
  border-bottom: 1px solid var(--color-line);
  box-shadow: var(--shadow-soft);
}

.site-nav--mobile.is-open {
  display: block;
}

.site-nav--mobile .site-nav__list {
  flex-direction: column;
  align-items: stretch;
  gap: 0.25rem;
}

.site-nav--mobile .site-nav__link {
  display: block;
  padding: 0.85rem 0.5rem;
  font-size: 1.1rem;
  border-bottom: 1px solid var(--color-line);
}

.site-nav--mobile .site-nav__link::after {
  display: none;
}

@media (min-width: 900px) {
  .nav-toggle,
  .site-nav--mobile {
    display: none !important;
  }

  .site-nav {
    display: block;
  }
}