.site-header {
  position: relative;
  z-index: 100;
  background-color: var(--color-white);
  border-bottom: var(--border-light);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  width: 100%;
  max-width: var(--container-standard);
  margin-inline: auto;
  padding-inline: var(--container-padding-mobile);
  min-height: 72px;
}

.site-header__brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: var(--color-navy-900);
  flex-shrink: 0;
  min-width: 0;
}

.site-header__brand:hover {
  text-decoration: none;
}

.site-header__logo {
  width: 40px;
  height: 40px;
  object-fit: contain;
  flex-shrink: 0;
}

.site-header__brand-text {
  font-family: var(--font-heading);
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--color-navy-900);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.site-header__toggle {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  border-radius: var(--radius-sm);
  background-color: transparent;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
  flex-shrink: 0;
}

.site-header__toggle:hover {
  background-color: var(--color-sand-200);
}

.site-header__toggle:focus-visible {
  outline: var(--focus-outline);
  outline-offset: var(--focus-offset);
}

.site-header__toggle-line {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--color-navy-900);
  border-radius: 1px;
  transition: transform var(--transition-base), opacity var(--transition-base);
  transform-origin: center;
}

.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 {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  width: 100%;
  max-height: calc(100vh - 72px);
  overflow-y: auto;
  background-color: var(--color-white);
  border-bottom: var(--border-light);
  box-shadow: var(--shadow-elevated);
  padding: var(--space-4) var(--container-padding-mobile) var(--space-6);
  z-index: 99;
}

.site-header__nav.is-open {
  display: block;
}

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

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

.site-header__nav-link {
  display: block;
  padding: var(--space-3) var(--space-4);
  font-family: var(--font-body);
  font-size: var(--text-body-size);
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--color-navy-900);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.site-header__nav-link:hover {
  background-color: var(--color-sand-200);
  color: var(--color-navy-900);
  text-decoration: none;
}

.site-header__nav-link:focus-visible {
  outline: var(--focus-outline);
  outline-offset: var(--focus-offset);
}

@media (min-width: 900px) {
  .site-header__inner {
    min-height: 80px;
    padding-inline: var(--container-padding-desktop);
  }

  .site-header__logo {
    width: 40px;
    height: 40px;
  }

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

  .site-header__toggle {
    display: none;
  }

  .site-header__nav {
    display: block;
    position: static;
    max-height: none;
    overflow-y: visible;
    background-color: transparent;
    border-bottom: none;
    box-shadow: none;
    padding: 0;
    width: auto;
    flex-shrink: 0;
  }

  .site-header__nav-list {
    flex-direction: row;
    align-items: center;
    gap: var(--space-5);
  }

  .site-header__nav-link {
    display: inline-block;
    padding: var(--space-2) 0;
    font-size: 0.9375rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    color: var(--color-navy-900);
    border-radius: 0;
    position: relative;
  }

  .site-header__nav-link::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    height: 2px;
    background-color: var(--color-sea-blue-500);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-base);
  }

  .site-header__nav-link:hover {
    background-color: transparent;
    color: var(--color-sea-blue-500);
  }

  .site-header__nav-link:hover::after,
  .site-header__nav-link:focus-visible::after {
    transform: scaleX(1);
  }

  .site-header__nav-link:focus-visible {
    outline: var(--focus-outline);
    outline-offset: var(--focus-offset);
  }
}

@media (prefers-reduced-motion: reduce) {
  .site-header__toggle-line,
  .site-header__nav-link::after {
    transition: none;
  }
}