.site-header {
  position: relative;
  z-index: 1000;
  background-color: var(--color-paper);
  border-bottom: var(--rule-width-masthead) solid var(--color-rule);
}

.site-header__inner {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: var(--space-md);
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-padding-mobile);
  min-height: var(--masthead-height-mobile);
}

.site-header__nav {
  display: none;
}

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

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

.site-header__nav-link {
  display: inline-block;
  font-size: var(--text-body-sm-size);
  line-height: var(--text-body-sm-line-height);
  letter-spacing: var(--text-body-sm-letter-spacing);
  color: var(--color-ink);
  text-decoration: none;
  padding-block: var(--space-xs);
  position: relative;
  white-space: nowrap;
}

.site-header__nav-link::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: var(--rule-width);
  background-color: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-fast) ease;
}

.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-ring-width) solid var(--color-focus);
  outline-offset: var(--focus-ring-offset);
  border-radius: var(--radius-0);
}

.site-header__brand {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  text-decoration: none;
  color: var(--color-ink);
  justify-self: center;
  min-width: 0;
}

.site-header__logo {
  width: 2rem;
  height: 2rem;
  object-fit: contain;
  flex-shrink: 0;
}

.site-header__brand-text {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  line-height: 1.2;
  letter-spacing: 0.01em;
  font-weight: 600;
  white-space: nowrap;
}

.site-header__toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 2.75rem;
  height: 2.75rem;
  padding: 0;
  background: none;
  border: none;
  border-radius: var(--radius-1);
  cursor: pointer;
  justify-self: end;
}

.site-header__toggle-line {
  display: block;
  width: 1.25rem;
  height: 2px;
  background-color: var(--color-ink);
  transition: transform var(--transition-menu) ease, opacity var(--transition-menu) 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__toggle:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus);
  outline-offset: var(--focus-ring-offset);
}

.site-header__mobile-nav {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background-color: var(--color-paper);
  border-bottom: var(--rule-width) solid var(--color-rule);
  max-height: calc(100vh - var(--masthead-height-mobile));
  overflow-y: auto;
  z-index: 999;
}

.site-header__mobile-nav.is-open {
  display: block;
}

.site-header__mobile-list {
  list-style: none;
  margin: 0;
  padding: var(--space-sm) 0;
}

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

.site-header__mobile-link {
  display: block;
  padding: var(--space-sm) var(--container-padding-mobile);
  font-size: var(--text-body-size);
  line-height: var(--text-body-line-height);
  letter-spacing: var(--text-body-letter-spacing);
  color: var(--color-ink);
  text-decoration: none;
  border-bottom: var(--rule-width) solid var(--color-rule-soft);
}

.site-header__mobile-link:hover,
.site-header__mobile-link:focus-visible {
  background-color: var(--color-note);
  color: var(--color-accent);
}

.site-header__mobile-link:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus);
  outline-offset: calc(-1 * var(--focus-ring-offset));
}

@media (min-width: 48rem) {
  .site-header__inner {
    min-height: var(--masthead-height-desktop);
    padding-inline: var(--container-padding-tablet);
  }

  .site-header__logo {
    width: 2.75rem;
    height: 2.75rem;
  }

  .site-header__brand-text {
    font-size: 1.625rem;
  }

  .site-header__mobile-nav {
    max-height: calc(100vh - var(--masthead-height-desktop));
  }
}

@media (min-width: 64rem) {
  .site-header__nav {
    display: block;
  }

  .site-header__nav--left {
    justify-self: start;
  }

  .site-header__nav--right {
    justify-self: end;
  }

  .site-header__toggle {
    display: none;
  }

  .site-header__mobile-nav {
    display: none !important;
  }
}

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

  .site-header__toggle-line {
    transition: none;
  }
}