.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background-color: var(--color-alabaster);
  border-bottom: 1px solid var(--color-silver);
  transition: background-color var(--transition-duration) var(--transition-ease),
    box-shadow var(--transition-duration) var(--transition-ease);
}

.site-header--scrolled {
  background-color: var(--color-white);
  box-shadow: var(--shadow-subtle);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--container-max-width);
  margin-inline: auto;
  padding-inline: var(--container-padding-mobile);
  height: var(--header-height-mobile);
  gap: var(--space-3);
}

.site-header__brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  flex-shrink: 0;
  min-width: 0;
}

.site-header__logo {
  width: 36px;
  height: 36px;
  object-fit: contain;
  flex-shrink: 0;
}

.site-header__brand-text {
  font-family: var(--font-body);
  font-size: var(--text-small-size);
  line-height: var(--text-small-line-height);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-ultramarine);
  font-weight: 600;
  white-space: nowrap;
}

.site-header__toggle {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 44px;
  height: 44px;
  padding: 0;
  background: transparent;
  border: none;
  cursor: pointer;
  flex-shrink: 0;
  gap: 5px;
  transition: background-color var(--transition-duration) var(--transition-ease);
}

.site-header__toggle:hover {
  background-color: var(--color-white);
}

.site-header__toggle:focus-visible {
  outline: var(--focus-outline-width) solid var(--focus-outline-color);
  outline-offset: 2px;
}

.site-header__toggle-line {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--color-ultramarine);
  border-radius: 1px;
  transition: transform var(--transition-duration) var(--transition-ease),
    opacity var(--transition-duration) var(--transition-ease);
}

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

.site-header__toggle[aria-expanded="true"] .site-header__toggle-line:nth-child(2) {
  opacity: 0;
}

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

.site-header__nav {
  position: fixed;
  top: var(--header-height-mobile);
  right: 0;
  bottom: 0;
  width: min(320px, 100vw);
  background-color: var(--color-white);
  box-shadow: var(--shadow-elevated);
  transform: translateX(100%);
  transition: transform var(--transition-duration) var(--transition-ease);
  overflow-y: auto;
  z-index: 999;
  padding: var(--space-4);
  visibility: hidden;
}

.site-header__nav.is-open {
  transform: translateX(0);
  visibility: visible;
}

.site-header__nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.site-header__nav-item {
  margin: 0;
  padding: 0;
}

.site-header__nav-link {
  display: block;
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-body);
  font-size: var(--text-body-size);
  line-height: var(--text-body-line-height);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-ink);
  border-radius: var(--radius-small);
  transition: background-color var(--transition-duration) var(--transition-ease),
    color var(--transition-duration) var(--transition-ease);
}

.site-header__nav-link:hover {
  background-color: var(--color-alabaster);
  color: var(--color-ultramarine);
}

.site-header__nav-link:focus-visible {
  outline: var(--focus-outline-width) solid var(--focus-outline-color);
  outline-offset: 2px;
}

@media (min-width: 768px) {
  .site-header__inner {
    height: var(--header-height);
    padding-inline: var(--container-padding-desktop);
  }

  .site-header__logo {
    width: 44px;
    height: 44px;
  }

  .site-header__toggle {
    display: none;
  }

  .site-header__nav {
    position: static;
    width: auto;
    background-color: transparent;
    box-shadow: none;
    transform: none;
    transition: none;
    overflow-y: visible;
    z-index: auto;
    padding: 0;
    visibility: visible;
  }

  .site-header__nav-list {
    flex-direction: row;
    align-items: center;
    gap: var(--space-4);
  }

  .site-header__nav-link {
    padding: var(--space-1) var(--space-2);
    font-size: var(--text-small-size);
    line-height: var(--text-small-line-height);
    white-space: nowrap;
  }

  .site-header__nav-link:hover {
    background-color: transparent;
    color: var(--color-ultramarine);
    text-decoration: underline;
    text-underline-offset: 4px;
    text-decoration-color: var(--color-silver);
  }
}

@media (min-width: 992px) {
  .site-header__nav-list {
    gap: var(--space-5);
  }
}