.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-header-bg);
  border-bottom: 2px solid var(--color-border-strong);
  box-shadow: var(--shadow-sm);
}

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

.site-header__logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-primary);
  flex-shrink: 0;
}

.site-header__toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 2.75rem;
  height: 2.75rem;
  padding: var(--space-xs);
  border: 2px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  -webkit-tap-highlight-color: transparent;
}

.site-header__toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-primary);
  border-radius: 1px;
  transition:
    transform var(--transition-base),
    opacity var(--transition-base);
}

.site-nav {
  display: none;
}

.site-nav__list {
  display: flex;
  flex-direction: column;
  gap: 0;
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav__item {
  position: relative;
}

.site-nav__link,
.site-nav__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-sm);
  font-family: var(--font-display);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  text-align: left;
  color: var(--color-text);
  transition:
    background-color var(--transition-base),
    color var(--transition-base);
  -webkit-tap-highlight-color: transparent;
}

.site-nav__link:hover,
.site-nav__link:focus-visible,
.site-nav__trigger:hover,
.site-nav__trigger:focus-visible {
  background: var(--color-bg);
  color: var(--color-accent);
}

.site-nav__trigger-icon {
  width: 0.75rem;
  height: 0.75rem;
  transition: transform var(--transition-base);
}

.site-nav__item--open > .site-nav__trigger .site-nav__trigger-icon {
  transform: rotate(180deg);
}

.site-nav__submenu {
  display: none;
  padding-left: var(--space-md);
  list-style: none;
  margin: 0;
}

.site-nav__item--open > .site-nav__submenu {
  display: block;
}

.site-nav__submenu .site-nav__link {
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: 0.9375rem;
  letter-spacing: 0;
  text-transform: none;
  padding-block: var(--space-xs);
}

.site-nav__submenu--nested {
  padding-left: var(--space-lg);
}

.site-nav__lang {
  display: flex;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
}

.site-nav__lang-btn {
  padding: 0.25rem 0.5rem;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-family: var(--font-display);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.site-nav__lang-btn--active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-text-on-dark);
}

.site-header--nav-open .site-nav {
  display: block;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  padding: var(--space-md);
  background: var(--color-surface);
  border-bottom: 2px solid var(--color-border-strong);
  max-height: calc(100dvh - var(--header-height) - var(--topbar-height));
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

.site-header--nav-open .site-header__toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.site-header--nav-open .site-header__toggle-bar:nth-child(2) {
  opacity: 0;
}

.site-header--nav-open .site-header__toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

@media (min-width: 768px) and (max-width: 1023px) {
  .site-header__toggle {
    display: none;
  }

  .site-nav {
    display: block;
    position: static;
    padding: 0;
    max-height: none;
    overflow-x: auto;
    overflow-y: visible;
    -webkit-overflow-scrolling: touch;
  }

  .site-nav__list {
    flex-direction: row;
    align-items: center;
    flex-wrap: nowrap;
    gap: 0;
  }

  .site-nav__link,
  .site-nav__trigger {
    padding: var(--space-xs) var(--space-sm);
    white-space: nowrap;
    font-size: 0.6875rem;
  }

  .site-nav__submenu {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 14rem;
    padding: var(--space-sm);
    background: var(--color-surface);
    border: 2px solid var(--color-border-strong);
    border-radius: var(--radius-md);
    box-shadow: 0 8px 24px rgb(26 35 50 / 12%);
    z-index: 50;
  }

  .site-nav__item--dropdown:hover > .site-nav__submenu,
  .site-nav__item--dropdown:focus-within > .site-nav__submenu,
  .site-nav__item--dropdown.site-nav__item--open > .site-nav__submenu {
    display: block;
  }

  .site-nav__submenu--nested {
    position: static;
    padding-left: var(--space-md);
    border: none;
    box-shadow: none;
    min-width: auto;
  }
}

@media (min-width: 1024px) {
  .site-header__toggle {
    display: none;
  }

  .site-nav {
    display: block;
    position: static;
    padding: 0;
    max-height: none;
    overflow: visible;
  }

  .site-nav__list {
    flex-direction: row;
    align-items: center;
    gap: var(--space-xs);
  }

  .site-nav__link,
  .site-nav__trigger {
    width: auto;
    padding: var(--space-xs) var(--space-sm);
    font-size: 0.75rem;
  }

  .site-nav__submenu {
    position: absolute;
    top: calc(100% + 4px);
    left: 0;
    min-width: 15rem;
    padding: var(--space-sm);
    background: var(--color-surface);
    border: 2px solid var(--color-border-strong);
    border-radius: var(--radius-md);
    box-shadow: 0 8px 24px rgb(26 35 50 / 12%);
    z-index: 50;
  }

  .site-nav__item--dropdown:hover > .site-nav__submenu,
  .site-nav__item--dropdown:focus-within > .site-nav__submenu {
    display: block;
  }

  .site-nav__submenu--nested {
    position: absolute;
    top: 0;
    left: 100%;
    margin-left: 4px;
    min-width: 12rem;
  }

  .site-nav__item--nested:hover > .site-nav__submenu--nested,
  .site-nav__item--nested:focus-within > .site-nav__submenu--nested {
    display: block;
  }

  .site-nav__lang {
    padding: 0;
    margin-left: var(--space-xs);
  }
}