.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--header-height);
  z-index: 100;
}

/* Own layer for the blur: backdrop-filter on .site-header itself would create a new
   containing block, breaking position:fixed on the mobile nav panel nested inside it. */
.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: var(--color-header-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  transition: background var(--transition-base), border-color var(--transition-base);
}

.site-header .container {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.site-header__logo {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.site-header__logo img {
  height: 26px;
  width: auto;
}

.site-header__logo .logo-dark { display: none; }
:root[data-theme="dark"] .site-header__logo .logo-light { display: none; }
:root[data-theme="dark"] .site-header__logo .logo-dark { display: block; }

.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}

.site-nav a {
  display: block;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: background var(--transition-fast), color var(--transition-fast);
}

.site-nav a:hover {
  color: var(--color-text);
  background: var(--color-bg-alt);
}

.site-nav a[aria-current="page"] {
  color: var(--color-primary);
  font-weight: 600;
}

.site-header__actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 1px solid var(--color-border);
  background: transparent;
  color: var(--color-text);
  transition: border-color var(--transition-fast), color var(--transition-fast);
}

.theme-toggle:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.theme-toggle svg {
  width: 18px;
  height: 18px;
}

.theme-toggle .icon-sun { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-moon { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-sun { display: block; }

.nav-toggle {
  display: none;
  width: 38px;
  height: 38px;
  border: none;
  background: transparent;
  color: var(--color-text);
  align-items: center;
  justify-content: center;
}

.nav-toggle svg {
  width: 24px;
  height: 24px;
}

.nav-toggle .icon-close { display: none; }

@media (max-width: 900px) {
  .site-nav {
    position: fixed;
    inset: var(--header-height) 0 0 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--color-bg);
    padding: 12px 24px 32px;
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity var(--transition-base), transform var(--transition-base), visibility var(--transition-base);
    overflow-y: auto;
  }

  .site-nav a {
    padding: 14px 4px;
    font-size: 1.05rem;
    border-bottom: 1px solid var(--color-border);
    border-radius: 0;
  }

  .site-header__actions {
    order: 3;
  }

  .site-header__actions .btn-ghost {
    display: none;
  }

  .nav-toggle {
    display: inline-flex;
  }

  html.nav-open .site-nav {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }

  html.nav-open .nav-toggle .icon-menu { display: none; }
  html.nav-open .nav-toggle .icon-close { display: block; }
  html.nav-open body { overflow: hidden; }
}

@media (max-width: 560px) {
  .site-header__actions .btn-primary span {
    display: none;
  }
  .site-header__actions .btn-primary {
    padding: 10px 14px;
  }
}