.site-header {
  position: relative;
  z-index: 1000;
  background-color: var(--color-surface);
  border-bottom: var(--border-width) var(--border-style) var(--color-neutral);
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  max-width: var(--container-max-width);
  margin-inline: auto;
  padding: var(--space-3) var(--container-gutter);
  min-height: 64px;
}

.site-header__brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--color-primary);
  flex-shrink: 0;
}

.site-header__brand:hover {
  color: var(--color-secondary);
}

.site-header__logo {
  width: 48px;
  height: 48px;
  object-fit: contain;
  display: block;
}

.site-header__brand-text {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.2;
  white-space: nowrap;
}

.site-header__search {
  flex: 1 1 auto;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  max-width: 480px;
  margin-inline: auto;
  position: relative;
}

.site-header__search-input {
  flex: 1 1 auto;
  padding: var(--space-2) var(--space-4);
  border: var(--border-width) var(--border-style) var(--color-neutral);
  border-radius: var(--radius-small);
  background-color: var(--color-background);
  font-family: var(--font-body);
  font-size: var(--text-body-size);
  line-height: 1.5;
  color: var(--color-text-on-light);
  min-height: 44px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.site-header__search-input::placeholder {
  color: var(--color-secondary);
  opacity: 0.8;
}

.site-header__search-input:focus {
  border-color: var(--color-accent);
  outline: none;
  box-shadow: 0 0 0 1px var(--color-accent);
}

.site-header__search-submit {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-small);
  background-color: var(--color-primary);
  color: var(--color-text-on-dark);
  transition: background-color 0.2s ease;
  flex-shrink: 0;
}

.site-header__search-submit:hover {
  background-color: var(--color-secondary);
}

.site-header__search-icon {
  display: block;
}

.site-header__menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0;
  border-radius: var(--radius-small);
  background-color: transparent;
  border: var(--border-width) var(--border-style) var(--color-neutral);
  transition: border-color 0.2s ease, background-color 0.2s ease;
  flex-shrink: 0;
}

.site-header__menu-toggle:hover {
  border-color: var(--color-secondary);
  background-color: var(--color-background);
}

.site-header__menu-toggle-line {
  display: block;
  width: 20px;
  height: 2px;
  background-color: var(--color-primary);
  border-radius: 1px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

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

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

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

.site-header__nav {
  display: block;
}

.site-header__nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  list-style: none;
  margin: 0;
  padding: 0;
}

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

.site-header__nav-link {
  display: inline-flex;
  align-items: center;
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-body);
  font-size: var(--text-small-size);
  line-height: 1.25;
  font-weight: 600;
  color: var(--color-primary);
  text-decoration: none;
  border-radius: var(--radius-small);
  white-space: nowrap;
  transition: color 0.2s ease, background-color 0.2s ease;
}

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

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

@media (max-width: 1024px) {
  .site-header__inner {
    flex-wrap: wrap;
  }

  .site-header__search {
    order: 3;
    flex-basis: 100%;
    max-width: none;
    margin-inline: 0;
  }

  .site-header__menu-toggle {
    display: flex;
  }

  .site-header__nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--color-surface);
    border-bottom: var(--border-width) var(--border-style) var(--color-neutral);
    box-shadow: var(--shadow-subtle);
    max-height: calc(100vh - 100%);
    overflow-y: auto;
    z-index: 1001;
  }

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

  .site-header__nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--space-3) var(--container-gutter);
  }

  .site-header__nav-item {
    border-bottom: var(--border-width) var(--border-style) var(--color-neutral);
  }

  .site-header__nav-item:last-child {
    border-bottom: none;
  }

  .site-header__nav-link {
    display: block;
    padding: var(--space-3) var(--space-2);
    font-size: var(--text-body-size);
    white-space: normal;
  }
}

@media (max-width: 768px) {
  .site-header__inner {
    padding: var(--space-2) var(--container-gutter);
    min-height: 56px;
  }

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

  .site-header__brand-text {
    font-size: 1rem;
  }

  .site-header__search-input {
    min-height: 40px;
    padding: var(--space-1) var(--space-3);
  }

  .site-header__search-submit {
    width: 40px;
    height: 40px;
  }

  .site-header__menu-toggle {
    width: 40px;
    height: 40px;
  }
}