/* nav.css — Global sticky navigation */

.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  background-color: var(--nav-bg);
  border-bottom: 1px solid transparent;
  transition:
    border-color var(--duration-fast) var(--easing-default),
    box-shadow var(--duration-fast) var(--easing-default);
}
.site-nav.is-scrolled {
  border-color: var(--color-border-secondary);
  box-shadow: var(--shadow-sm);
}

.nav-inner {
  display: flex;
  align-items: center;
  height: 100%;
  gap: var(--space-5);
}

/* Logo */
.nav-logo-link {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  text-decoration: none;
}
.nav-logo {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center;
  display: block;
}

/* Center links */
.nav-links {
  display: flex;
  align-items: center;
  gap: clamp(var(--space-4), 2vw, var(--space-6));
  flex: 1;
  justify-content: center;
}
.nav-link {
  font-family: var(--font-family-body);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--nav-link-color);
  text-decoration: none;
  letter-spacing: var(--letter-spacing-normal);
  white-space: nowrap;
  position: relative;
  padding-bottom: 2px;
  transition: color var(--duration-fast) var(--easing-default);
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--color-accent-primary);
  border-radius: 1px;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--duration-normal) var(--easing-out);
}
.nav-link:hover { color: var(--nav-link-color-hover); }
.nav-link:hover::after,
.nav-link.is-active::after { transform: scaleX(1); }
.nav-link.is-active { color: var(--nav-link-color-active); }

/* Donate CTA pill */
.nav-cta {
  flex-shrink: 0;
  padding: var(--space-2) var(--space-5);
  font-size: var(--font-size-xs);
}

/* Burger button */
.nav-burger {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-2);
  border-radius: var(--border-radius-md);
  margin-left: auto;
  flex-shrink: 0;
}
.burger-bar {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--color-text-primary);
  border-radius: 2px;
  transition:
    transform var(--duration-normal) var(--easing-default),
    opacity var(--duration-fast) var(--easing-default);
}
.nav-burger[aria-expanded="true"] .burger-bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-burger[aria-expanded="true"] .burger-bar:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav-burger[aria-expanded="true"] .burger-bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Mobile drawer */
.nav-drawer {
  position: fixed;
  top: var(--nav-height);
  right: 0;
  bottom: 0;
  width: min(320px, 85vw);
  background-color: var(--color-bg-secondary);
  border-left: 1px solid var(--color-border-secondary);
  transform: translateX(100%);
  transition: transform var(--duration-slow) var(--easing-out);
  z-index: 99;
  overflow-y: auto;
  padding: var(--space-7) var(--space-6);
  display: flex;
  flex-direction: column;
}
.nav-drawer.is-open { transform: translateX(0); }

.drawer-links { display: flex; flex-direction: column; }
.drawer-link {
  font-family: var(--font-family-body);
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  text-decoration: none;
  padding: var(--space-4) 0;
  border-bottom: 1px solid var(--color-border-secondary);
  transition: color var(--duration-fast) var(--easing-default);
}
.drawer-link:hover,
.drawer-link.is-active { color: var(--color-accent-secondary); }
.drawer-cta { margin-top: var(--space-7); width: 100%; padding: var(--space-4) var(--space-6); font-size: var(--font-size-base); }

/* Overlay */
.nav-overlay {
  position: fixed;
  inset: 0;
  background: var(--color-surface-overlay);
  z-index: 98;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--duration-slow) var(--easing-default);
}
.nav-overlay.is-visible { opacity: 1; pointer-events: all; }

/* ─── Responsive ─── */
@media (max-width: 768px) {
  .nav-links,
  .nav-cta { display: none; }
  .nav-burger { display: flex; }
}
@media (min-width: 769px) {
  .nav-drawer,
  .nav-overlay { display: none !important; }
}