.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  /* Keep blur/bg on ::before — backdrop-filter on this element would
     become a containing block for the fixed mobile nav and collapse it. */
  background-color: transparent;
  border-bottom: 1px solid var(--color-line);
}

.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-color: rgba(11, 14, 26, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  pointer-events: none;
}

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

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

.site-header__brand:hover {
  text-decoration: none;
  color: var(--color-text-primary);
}

.site-header__logo {
  width: 28px;
  height: 28px;
  display: block;
  flex-shrink: 0;
}

.site-header__brand-text {
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.site-header__nav {
  display: none;
  flex: 1 1 auto;
  justify-content: center;
  min-width: 0;
}

.site-header__nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-5);
  list-style: none;
  margin: 0;
  padding: 0;
}

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

.site-header__nav-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: var(--space-2) 0;
  font-size: var(--text-body-sm-size);
  line-height: var(--text-body-sm-line-height);
  font-weight: 500;
  color: var(--color-text-secondary);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--transition-color);
  position: relative;
}

.site-header__nav-link:hover {
  color: var(--color-text-primary);
  text-decoration: none;
}

.site-header__nav-link[aria-current="page"] {
  color: var(--color-text-primary);
}

.site-header__nav-link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background-color: var(--color-accent-cyan);
  border-radius: 1px;
}

.site-header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
}

.site-header__cta {
  display: none;
  padding: var(--space-2) var(--space-4);
  min-height: 40px;
  font-size: var(--text-body-sm-size);
  line-height: 1;
}

.site-header__cta-icon {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

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

.site-header__toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background-color: var(--color-text-primary);
  border-radius: 1px;
  transition: transform var(--transition-transform), opacity var(--transition-opacity);
}

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

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

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

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

@media (max-width: 1023px) {
  .site-header__nav {
    position: fixed;
    top: var(--header-height-mobile);
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 100;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    background-color: var(--color-ink);
    padding: var(--space-5) var(--container-padding-mobile) var(--space-7);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    transform: translateX(100%);
    visibility: hidden;
    transition: transform var(--transition-transform), visibility var(--transition-transform);
  }

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

  .site-header__actions {
    position: relative;
    z-index: 101;
  }

  .site-header__nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: var(--space-2);
    width: 100%;
  }

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

  .site-header__nav-link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 48px;
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-body-size);
    line-height: var(--text-body-line-height);
    font-weight: 500;
    color: var(--color-text-primary);
    border-radius: var(--radius-sm);
    background-color: transparent;
    transition: background-color var(--transition-color), color var(--transition-color);
  }

  .site-header__nav-link:hover {
    background-color: var(--color-ink-raised);
    color: var(--color-accent-cyan);
  }

  .site-header__nav-link[aria-current="page"] {
    color: var(--color-accent-cyan);
  }

  .site-header__nav-link[aria-current="page"]::after {
    display: none;
  }
}

@media (min-width: 1024px) {
  .site-header__inner {
    min-height: var(--header-height-desktop);
    padding-inline: var(--container-padding-desktop);
  }

  .site-header__logo {
    width: 36px;
    height: 36px;
  }

  .site-header__brand-text {
    font-size: 1.125rem;
  }

  .site-header__nav {
    display: flex;
  }

  .site-header__cta {
    display: inline-flex;
  }

  .site-header__toggle {
    display: none;
  }
}

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

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