.site-header {
  position: sticky;
  z-index: 900;
  top: 0;
  min-height: 72px;
  border-bottom: 1px solid var(--color-line-700);
  background: rgba(15, 23, 42, 0.97);
  box-shadow: 0 8px 20px rgba(2, 6, 23, 0.18);
}

.site-header__inner {
  display: flex;
  min-height: 72px;
  align-items: center;
  gap: var(--space-6);
}

.site-header__brand {
  display: inline-flex;
  min-width: 0;
  flex: 0 1 auto;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-text-strong);
  text-decoration: none;
  white-space: nowrap;
}

.site-header__brand:hover {
  color: var(--color-text-strong);
  text-decoration: none;
}

.site-header__logo {
  width: 44px;
  height: 44px;
  flex: 0 0 44px;
  object-fit: contain;
}

.site-header__brand-text {
  overflow: hidden;
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1;
  text-overflow: ellipsis;
}

.site-header__navigation {
  display: flex;
  min-width: 0;
  flex: 1 1 auto;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}

.site-header__menu {
  display: flex;
  min-width: 0;
  align-items: center;
  gap: clamp(0.5rem, 1.15vw, 1.25rem);
  margin: 0;
  padding: 0;
}

.site-header__menu li,
.site-header__menu li + li {
  margin: 0;
  padding: 0;
}

.site-header__item--mobile-only {
  display: none;
}

.site-header__menu a {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  border-bottom: 2px solid transparent;
  color: var(--color-text-muted);
  font-size: 0.875rem;
  font-weight: 600;
  line-height: 1.2;
  text-decoration: none;
  white-space: nowrap;
}

.site-header__menu a:hover,
.site-header__menu a[aria-current="page"] {
  border-bottom-color: var(--color-sky-400);
  color: var(--color-text-strong);
}

.site-header__action {
  display: inline-flex;
  min-height: 44px;
  flex: 0 0 auto;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 0.875rem;
  border: 1px solid var(--color-orange-400);
  border-radius: var(--radius-control);
  background: var(--color-orange-400);
  color: var(--color-orange-on-action);
  font-size: 0.875rem;
  font-weight: 600;
  line-height: 1.2;
  text-align: center;
  text-decoration: none;
  white-space: nowrap;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.site-header__action:hover {
  color: var(--color-orange-on-action);
  box-shadow: var(--shadow-action);
  text-decoration: none;
  transform: translateY(-2px);
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  flex: 0 0 44px;
  align-items: center;
  justify-content: center;
  gap: 5px;
  padding: 0;
  border: 1px solid var(--color-line-700);
  border-radius: var(--radius-control);
  background: var(--color-panel-800);
  color: var(--color-text-strong);
}

.nav-toggle__line {
  display: block;
  width: 20px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

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

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

.nav-toggle:hover {
  border-color: var(--color-sky-400);
  color: var(--color-sky-400);
}

@media (max-width: 1039px) {
  .site-header {
    min-height: 64px;
  }

  .site-header__inner {
    min-height: 64px;
    justify-content: space-between;
    gap: var(--space-4);
  }

  .site-header__logo {
    width: 38px;
    height: 38px;
    flex-basis: 38px;
  }

  .site-header__brand-text {
    font-size: 1.25rem;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .site-header__navigation {
    position: absolute;
    top: calc(100% + 1px);
    right: 0;
    left: 0;
    display: none;
    max-height: calc(100vh - 64px);
    overflow-y: auto;
    padding: var(--space-4) var(--container-padding) var(--space-6);
    border-bottom: 1px solid var(--color-line-700);
    background: var(--color-panel-800);
    box-shadow: var(--shadow-panel);
  }

  .site-header__navigation.is-open {
    display: grid;
    gap: var(--space-4);
  }

  .site-header__menu {
    display: grid;
    gap: 0;
  }

  .site-header__item--mobile-only {
    display: block;
  }

  .site-header__menu a {
    width: 100%;
    min-height: 48px;
    border-bottom: 1px solid rgba(51, 65, 85, 0.8);
  }

  .site-header__menu a:hover,
  .site-header__menu a[aria-current="page"] {
    border-bottom-color: var(--color-sky-400);
  }

  .site-header__action {
    width: 100%;
  }
}

@media (max-width: 399px) {
  .site-header__inner {
    gap: var(--space-3);
  }

  .site-header__brand {
    gap: var(--space-2);
  }
}

ul { list-style: none !important; }
.nav-toggle { flex-direction: column; }