.header-shell {
  position: sticky;
  top: 0;
  z-index: var(--z-header);
}

.header-shell.mobile-nav-open {
  z-index: var(--z-overlay);
  background: rgba(3, 4, 10, 0.99);
  backdrop-filter: none;
  border-bottom-color: transparent;
}

.header-shell .header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  min-height: 64px;
}

.header-shell .header__brand {
  flex-shrink: 0;
  min-width: 0;
}

.header-shell .header__brand-text {
  min-width: 0;
}

.header-shell .header__nav {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  justify-content: center;
}

.header-shell .header__nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: clamp(0.35rem, 1vw, var(--space-md));
}

.header-shell .header__nav-item {
  margin: 0;
}

.header-shell .header__nav-link {
  text-decoration: none;
  font-size: clamp(0.62rem, 0.55rem + 0.25vw, 0.72rem);
  padding: 0.35rem 0.45rem;
}

.header-shell .header__menu-toggle {
  display: none;
  flex-shrink: 0;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  padding: 0;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(47, 211, 255, 0.6);
  background: radial-gradient(circle at top left, rgba(47, 211, 255, 0.22), transparent 60%), rgba(5, 7, 22, 0.98);
  color: var(--color-primary-strong);
  cursor: pointer;
  transition: background var(--transition-fast), box-shadow var(--transition-fast), transform var(--transition-fast);
}

.header-shell .header__menu-toggle:hover {
  box-shadow: 0 0 0 1px rgba(47, 211, 255, 0.7), 0 12px 30px rgba(0, 0, 0, 0.9);
  transform: translateY(-1px);
}

.header-shell .header__menu-toggle:active {
  transform: translateY(0);
}

.header-shell .header__menu-toggle-bar {
  width: 16px;
  height: 2px;
  border-radius: 999px;
  background: var(--color-primary-strong);
  display: block;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.header-shell .header__menu-toggle-bar + .header__menu-toggle-bar {
  margin-top: 3px;
}

.header-shell.mobile-nav-open .header__menu-toggle-bar:nth-child(1) {
  transform: translateY(5px) rotate(45deg);
}

.header-shell.mobile-nav-open .header__menu-toggle-bar:nth-child(2) {
  opacity: 0;
}

.header-shell.mobile-nav-open .header__menu-toggle-bar:nth-child(3) {
  transform: translateY(-5px) rotate(-45deg);
}

.mobile-nav {
  position: fixed;
  inset: 0;
  z-index: 1;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  overflow: hidden;
  background: #03040a;
  transition: opacity var(--transition-med), visibility var(--transition-med);
}

.mobile-nav__inner {
  min-height: 100%;
  padding-top: calc(var(--mobile-header-bar-height, 64px) + env(safe-area-inset-top, 0px));
  padding-bottom: calc(var(--space-xl) + env(safe-area-inset-bottom, 0px));
  overflow-y: auto;
}

.mobile-nav__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.mobile-nav__item {
  margin: 0;
}

.mobile-nav__link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 0;
  border-bottom: 1px solid rgba(47, 211, 255, 0.14);
  font-size: var(--text-sm);
  letter-spacing: var(--letter-wide-soft);
  text-transform: uppercase;
  text-decoration: none;
  color: var(--color-text);
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

.mobile-nav__link:hover,
.mobile-nav__link:focus-visible {
  color: var(--color-primary-strong);
  border-bottom-color: rgba(47, 211, 255, 0.35);
}

.mobile-nav__link[aria-current="page"] {
  color: var(--color-primary-strong);
  border-bottom-color: rgba(90, 224, 255, 0.45);
}

.header-shell.mobile-nav-open .mobile-nav {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

.header-shell.mobile-nav-open > .container {
  position: relative;
  z-index: 2;
  background: rgba(3, 4, 10, 0.99);
  border-bottom: 1px solid rgba(26, 31, 58, 0.9);
}

.header-shell.mobile-nav-open .header__brand {
  color: var(--color-text);
}

.header-shell.mobile-nav-open .header__brand-name {
  color: var(--color-text);
}

.header-shell.mobile-nav-open .header__menu-toggle {
  border-color: rgba(90, 224, 255, 0.75);
  color: var(--color-primary-strong);
}

@media (min-width: 1024px) {
  .header-shell .header {
    min-height: var(--header-height);
  }

  .mobile-nav {
    display: none;
  }
}

@media (max-width: 1023.98px) {
  .header-shell {
    --mobile-header-bar-height: 64px;
  }

  .header-shell .header__nav {
    display: none;
  }

  .header-shell .header__menu-toggle {
    display: inline-flex;
    flex-direction: column;
  }
}

@media (max-width: 767.98px) {
  .header-shell .header__brand-tagline {
    display: none;
  }

  .mobile-nav__inner {
    padding-inline: var(--space-md);
  }

  .mobile-nav__link {
    padding-inline: 0;
  }
}

@media (max-width: 479.98px) {
  .header-shell {
    --mobile-header-bar-height: 56px;
  }

  .header-shell .header {
    min-height: 56px;
    gap: var(--space-sm);
  }

  .header-shell .header__brand-mark {
    width: 24px;
    height: 24px;
  }

  .header-shell .header__brand-name {
    font-size: var(--text-sm);
  }
}