/* =============================================================
   Society of Scholar Writers — Navigation (navigation.css)
   ============================================================= */

/* ── Site Header ─────────────────────────────────────────────── */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-sticky);
  height: var(--header-height);
  background-color: rgba(248, 247, 244, 0.96);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-divider);
  transition: box-shadow var(--transition-interactive), background-color var(--transition-interactive);
}

[data-theme="dark"] .site-header {
  background-color: rgba(15, 18, 25, 0.96);
}

.site-header--scrolled {
  box-shadow: var(--shadow-md);
}

.site-header__inner {
  display: flex;
  align-items: center;
  height: 100%;
  gap: var(--space-8);
}

/* ── Logo ────────────────────────────────────────────────────── */
.site-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  flex-shrink: 0;
}

.site-logo:hover { text-decoration: none; }

.site-logo img {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  object-fit: contain;
}

.site-logo__name {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: var(--weight-bold);
  color: var(--color-text);
  line-height: var(--leading-snug);
  max-width: 140px;
}

/* ── Primary Nav ─────────────────────────────────────────────── */
.primary-nav {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.primary-nav__list {
  display: flex;
  align-items: center;
  gap: 0;
  list-style: none;
  padding: 0;
  margin: 0;
}

.primary-nav__item {
  position: relative;
  margin: 0;
}

.primary-nav__link {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--color-text-muted);
  text-decoration: none;
  border-radius: var(--radius-md);
  transition: color var(--transition-fast), background-color var(--transition-fast);
  white-space: nowrap;
  min-height: 44px;
}

.primary-nav__link:hover {
  color: var(--color-primary);
  background-color: rgba(1, 105, 111, 0.05);
  text-decoration: none;
}

.primary-nav__link--active {
  color: var(--color-primary);
  font-weight: var(--weight-semibold);
}

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

/* Dropdown arrow */
.primary-nav__arrow {
  width: 14px;
  height: 14px;
  transition: transform var(--transition-fast);
  flex-shrink: 0;
}

.primary-nav__item--open .primary-nav__arrow {
  transform: rotate(180deg);
}

/* ── Dropdown Menu ───────────────────────────────────────────── */
.dropdown {
  position: absolute;
  top: calc(100% + var(--space-2));
  left: 50%;
  transform: translateX(-50%) translateY(-8px);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  min-width: 260px;
  padding: var(--space-3);
  opacity: 0;
  visibility: hidden;
  transition:
    opacity var(--transition-interactive),
    transform var(--transition-interactive),
    visibility var(--transition-interactive);
  z-index: var(--z-dropdown);
  pointer-events: none;
}

.primary-nav__item--open .dropdown,
.primary-nav__item:hover .dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
  pointer-events: auto;
}

.dropdown__list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.dropdown__item { margin: 0; }

.dropdown__link {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.dropdown__link:hover {
  background-color: rgba(1, 105, 111, 0.06);
  color: var(--color-primary);
  text-decoration: none;
}

.dropdown__link-icon {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-md);
  background-color: var(--color-surface-2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  flex-shrink: 0;
}

.dropdown__link-text {
  font-weight: var(--weight-medium);
}

.dropdown__divider {
  height: 1px;
  background-color: var(--color-divider);
  margin: var(--space-2) var(--space-4);
}

/* ── Header Actions ──────────────────────────────────────────── */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-left: auto;
}

/* ── Theme Toggle ────────────────────────────────────────────── */
.theme-toggle {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: none;
  border: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--color-text-muted);
  transition: background-color var(--transition-fast), color var(--transition-fast);
  font-size: 1.1rem;
}

.theme-toggle:hover {
  background-color: var(--color-surface-2);
  color: var(--color-text);
}

.theme-toggle__moon { display: none; }
.theme-toggle__sun  { display: block; }

[data-theme="dark"] .theme-toggle__moon { display: block; }
[data-theme="dark"] .theme-toggle__sun  { display: none; }

/* ── Mobile menu toggle ──────────────────────────────────────── */
.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--color-text);
  flex-direction: column;
  gap: 5px;
  padding: var(--space-3);
}

.nav-toggle__line {
  display: block;
  width: 20px;
  height: 2px;
  background-color: currentColor;
  border-radius: 2px;
  transition: transform var(--transition-interactive), opacity var(--transition-fast), width var(--transition-interactive);
  transform-origin: center;
}

.nav-toggle--open .nav-toggle__line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle--open .nav-toggle__line:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.nav-toggle--open .nav-toggle__line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ── Mobile Navigation Overlay ───────────────────────────────── */
.mobile-nav {
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--color-bg);
  z-index: var(--z-overlay);
  overflow-y: auto;
  padding: var(--space-6);
  transform: translateX(100%);
  transition: transform var(--transition-slow);
  visibility: hidden;
}

.mobile-nav--open {
  transform: translateX(0);
  visibility: visible;
}

.mobile-nav__list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.mobile-nav__item { border-bottom: 1px solid var(--color-divider); margin: 0; }

.mobile-nav__link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) 0;
  font-size: var(--text-base);
  font-weight: var(--weight-medium);
  color: var(--color-text);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.mobile-nav__link:hover { color: var(--color-primary); text-decoration: none; }

.mobile-nav__submenu {
  list-style: none;
  padding: 0 0 var(--space-4) var(--space-4);
  margin: 0;
  display: none;
}

.mobile-nav__submenu--open { display: block; }

.mobile-nav__submenu-link {
  display: block;
  padding: var(--space-3) 0;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  border-bottom: 1px solid var(--color-divider);
}

.mobile-nav__submenu-link:hover { color: var(--color-primary); }

.mobile-nav__actions {
  margin-top: var(--space-8);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

/* ── Responsive breakpoints ──────────────────────────────────── */
@media (max-width: 900px) {
  .primary-nav { display: none; }
  .nav-toggle  { display: flex; }

  .header-actions .btn {
    display: none;
  }

  .header-actions .theme-toggle {
    display: flex;
  }
}

@media (max-width: 640px) {
  .site-logo__name { display: none; }
}