/* Site header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgb(10 15 26 / 90%);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid color-mix(in srgb, var(--color-primary) 25%, var(--color-border));
  overflow: visible;
}

[data-theme='light'] .site-header {
  background: rgb(240 249 255 / 90%);
}

.site-header__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-md) var(--space-xl);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-header__logo {
  font-weight: 800;
  font-size: var(--text-lg);
  color: var(--color-primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

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

.site-header__mark {
  height: 28px;
  width: auto;
}

.site-header__nav {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.site-header__nav a {
  color: color-mix(in srgb, var(--color-primary) 60%, var(--color-text-muted));
  text-decoration: none;
  font-weight: 500;
  transition: color 0.15s;
}

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

.site-header__mobile {
  display: none;
  align-items: center;
  gap: var(--space-sm);
}

.site-header__burger {
  display: flex;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-xs);
}

.site-header__burger span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-text);
  border-radius: 1px;
}

.btn-sm {
  padding: var(--space-xs) var(--space-md);
  font-size: var(--text-sm);
}

/* Theme toggle */
.theme-toggle-btn {
  font-size: var(--text-lg);
  padding: var(--space-xs) var(--space-sm);
  line-height: 1;
}

[data-theme='dark'] .theme-toggle-btn .icon {
  color: #fbbf24;
}

[data-theme='light'] .theme-toggle-btn .icon {
  color: #334155;
}

/* Mobile */
@media (width <= 640px) {
  .site-header__inner {
    padding: var(--space-sm) var(--space-md);
  }

  .site-header__nav {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgb(10 15 26 / 95%);
    backdrop-filter: blur(12px);
    padding: var(--space-md) var(--space-xl);
    gap: var(--space-md);
    border-bottom: 1px solid var(--color-border);
  }

  [data-theme='light'] .site-header__nav {
    background: rgb(240 249 255 / 95%);
  }

  .site-header__nav--open {
    display: flex;
  }

  .site-header__nav a {
    display: block;
    font-size: var(--text-base);
    padding: var(--space-xs) 0;
  }

  .site-header__mobile {
    display: flex;
  }
}