.site-header {
  position: relative;
  z-index: 1000;
  background-color: var(--color-warm-white);
  border-bottom: var(--border-width) solid var(--color-steel-gray);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.site-header__inner {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-2xs);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2xs);
  min-height: 72px;
}

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

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

.site-header__brand-text {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 20px;
  line-height: 1.2;
  letter-spacing: -0.01em;
  white-space: nowrap;
}

.site-header__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 8px;
  background: transparent;
  border: var(--border-width) solid var(--color-charcoal);
  border-radius: var(--radius-button);
  cursor: pointer;
  transition: border-color 0.2s ease, background-color 0.2s ease;
}

.site-header__toggle:hover,
.site-header__toggle:focus-visible {
  border-color: var(--color-tomato-red);
  background-color: rgba(226, 59, 46, 0.05);
}

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

.site-header__toggle-line {
  display: block;
  width: 20px;
  height: 2px;
  background-color: var(--color-charcoal);
  transition: transform 0.2s ease, opacity 0.2s 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 {
  display: block;
  flex-shrink: 1;
  min-width: 0;
}

.site-header__nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-2xs);
  list-style: none;
  margin: 0;
  padding: 0;
}

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

.site-header__nav-link {
  display: inline-block;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 14px;
  line-height: 1.2;
  letter-spacing: 0.01em;
  text-decoration: none;
  color: var(--color-charcoal);
  padding: var(--space-3xs) var(--space-2xs);
  border-radius: var(--radius-button);
  transition: color 0.2s ease, background-color 0.2s ease;
  white-space: nowrap;
}

.site-header__nav-link:hover,
.site-header__nav-link:focus-visible {
  color: var(--color-tomato-red);
  background-color: rgba(226, 59, 46, 0.05);
}

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

.site-header__nav-link[aria-current="page"] {
  color: var(--color-tomato-red);
  text-decoration: underline;
  text-underline-offset: 4px;
}

@media (max-width: 900px) {
  .site-header__inner {
    min-height: 64px;
  }

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

  .site-header__brand-text {
    font-size: 18px;
  }

  .site-header__toggle {
    display: flex;
  }

  .site-header__nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--color-warm-white);
    border-bottom: var(--border-width) solid var(--color-steel-gray);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
  }

  .site-header__nav.is-open {
    max-height: calc(100vh - 64px);
    overflow-y: auto;
  }

  .site-header__nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--space-3xs) var(--space-2xs);
  }

  .site-header__nav-item {
    width: 100%;
  }

  .site-header__nav-link {
    display: block;
    padding: var(--space-3xs) var(--space-2xs);
    font-size: 16px;
    border-radius: 0;
  }
}