/* =============================================================
   nav.css — Sticky navigation, dropdowns, mobile hamburger menu
   TKE Zeta Phi Foundation
   ============================================================= */

/* ── Nav Container ──────────────────────────────────────────── */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--color-white);
  border-bottom: 1px solid var(--color-gray-light);
  box-shadow: var(--shadow-sm);
  height: var(--nav-height);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

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

.nav-logo img {
  height: 44px;
  width: auto;
}

.nav-logo-text {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-dark);
  line-height: 1.3;
  max-width: 160px;
}

.nav-logo-text span {
  display: block;
  font-family: var(--font-body);
  font-weight: 400;
  font-size: var(--text-xs);
  color: var(--color-gray);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* ── Desktop Menu ───────────────────────────────────────────── */
.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.nav-item {
  position: relative;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-dark);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background-color var(--transition-fast);
  white-space: nowrap;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--color-red);
  background-color: var(--color-cream);
  outline: none;
}

.nav-link.active {
  color: var(--color-red);
}

/* Dropdown chevron indicator */
.nav-link[aria-haspopup="true"] .nav-chevron {
  display: inline-block;
  width: 0;
  height: 0;
  border-left: 4px solid transparent;
  border-right: 4px solid transparent;
  border-top: 5px solid currentColor;
  transition: transform var(--transition-fast);
}

.nav-item:hover .nav-link[aria-haspopup="true"] .nav-chevron,
.nav-item:focus-within .nav-link[aria-haspopup="true"] .nav-chevron {
  transform: rotate(180deg);
}

/* ── Dropdown Menu ──────────────────────────────────────────── */
.nav-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 180px;
  background: var(--color-white);
  border: 1px solid var(--color-gray-light);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  /* padding-top bridges the visual gap so hover is never broken */
  padding: 6px 0 var(--space-2);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  transition:
    opacity var(--transition-base),
    transform var(--transition-base),
    visibility var(--transition-base);
  pointer-events: none;
}

/* Open state — triggered by hover or focus-within on desktop */
.nav-item:hover .nav-dropdown,
.nav-item:focus-within .nav-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  pointer-events: auto;
}

.nav-dropdown-link {
  display: block;
  padding: var(--space-2) var(--space-5);
  font-size: var(--text-sm);
  color: var(--color-dark);
  text-decoration: none;
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.nav-dropdown-link:hover,
.nav-dropdown-link:focus-visible {
  background-color: var(--color-cream);
  color: var(--color-red);
  outline: none;
}

/* ── Donate CTA Button ──────────────────────────────────────── */
.nav-donate {
  display: inline-flex;
  align-items: center;
  padding: var(--space-2) var(--space-5);
  background-color: var(--color-red);
  color: var(--color-white) !important;
  font-size: var(--text-sm);
  font-weight: 700;
  border-radius: var(--radius-full);
  text-decoration: none;
  transition: background-color var(--transition-fast), transform var(--transition-fast);
  margin-left: var(--space-2);
}

.nav-donate:hover,
.nav-donate:focus-visible {
  background-color: var(--color-red-dark);
  color: var(--color-white) !important;
  transform: translateY(-1px);
  outline: 2px solid var(--color-red-dark);
  outline-offset: 2px;
}

/* ── Hamburger Button (mobile only) ────────────────────────── */
.nav-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: var(--space-2);
  border-radius: var(--radius-sm);
  color: var(--color-dark);
  transition: background-color var(--transition-fast);
}

.nav-hamburger:hover,
.nav-hamburger:focus-visible {
  background-color: var(--color-cream);
  outline: none;
}

.hamburger-bar {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--color-dark);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base);
  transform-origin: center;
}

/* X state when menu is open */
.nav-hamburger[aria-expanded="true"] .hamburger-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-hamburger[aria-expanded="true"] .hamburger-bar:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

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

/* ── Mobile Menu ────────────────────────────────────────────── */
.nav-mobile {
  display: none; /* shown only on mobile */
  position: fixed;
  top: var(--nav-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-white);
  overflow-y: auto;
  z-index: 999;
  padding: var(--space-4) 0 var(--space-8);

  /* Slide-down animation */
  transform: translateY(-8px);
  opacity: 0;
  visibility: hidden;
  transition:
    transform var(--transition-base),
    opacity var(--transition-base),
    visibility var(--transition-base);
}

.nav-mobile.is-open {
  transform: translateY(0);
  opacity: 1;
  visibility: visible;
}

.nav-mobile-item {
  border-bottom: 1px solid var(--color-gray-light);
}

.nav-mobile-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: var(--space-4) var(--space-6);
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-dark);
  text-decoration: none;
  background: none;
  text-align: left;
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.nav-mobile-link:hover,
.nav-mobile-link:focus-visible {
  color: var(--color-red);
  background-color: var(--color-cream);
  outline: none;
}

.nav-mobile-link.active {
  color: var(--color-red);
}

/* Mobile accordion chevron */
.mobile-chevron {
  display: inline-block;
  width: 0;
  height: 0;
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  border-top: 6px solid currentColor;
  transition: transform var(--transition-base);
  flex-shrink: 0;
}

.nav-mobile-link[aria-expanded="true"] .mobile-chevron {
  transform: rotate(180deg);
}

/* Mobile accordion panel */
.nav-mobile-accordion {
  overflow: hidden;
  max-height: 0;
  transition: max-height var(--transition-slow);
  background-color: var(--color-cream);
}

.nav-mobile-accordion.is-open {
  max-height: 400px; /* large enough for any dropdown content */
}

.nav-mobile-sub-link {
  display: block;
  padding: var(--space-3) var(--space-8);
  font-size: var(--text-sm);
  color: var(--color-dark);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.nav-mobile-sub-link:hover,
.nav-mobile-sub-link:focus-visible {
  color: var(--color-red);
  outline: none;
}

/* Mobile Donate button */
.nav-mobile-donate {
  display: block;
  margin: var(--space-6) var(--space-6) 0;
  padding: var(--space-3) var(--space-6);
  background-color: var(--color-red);
  color: var(--color-white);
  font-weight: 700;
  font-size: var(--text-base);
  text-align: center;
  border-radius: var(--radius-full);
  text-decoration: none;
  transition: background-color var(--transition-fast);
}

.nav-mobile-donate:hover {
  background-color: var(--color-red-dark);
  color: var(--color-white);
}

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

  .nav-hamburger {
    display: flex;
  }

  .nav-mobile {
    display: block;
  }
}