/*
 * nav.css — Site Navigation
 * ─────────────────────────────────────────────────────────────────
 * BEM class names: .nav, .nav__*, .nav--modifier
 * All values come from tokens.css.
 * ─────────────────────────────────────────────────────────────────
 */

/* ── Outer Shell ───────────────────────────────────────────────── */

.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  background: var(--nav-bg);
  border-bottom: 1px solid var(--nav-border);
  /* Subtle backdrop blur — cosmetic only, degrades gracefully */
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.nav__inner {
  max-width: var(--max-width);
  height: 100%;
  margin: 0 auto;
  padding: 0 var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
}

/* ── Logo ──────────────────────────────────────────────────────── */

.nav__logo {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: var(--space-3);
  line-height: 1;
  flex-shrink: 0;
}

.nav__logo-img {
  height: calc(var(--nav-height) - var(--space-4));
  width: auto;
}

.nav__logo-text {
  display: flex;
  flex-direction: column;
}

.nav__logo-primary {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: var(--weight-medium);
  letter-spacing: var(--tracking-tight);
  color: var(--clr-ink);
  white-space: nowrap;
}

.nav__logo-sub {
  font-family: var(--font-ui);
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  letter-spacing: var(--tracking-wider);
  text-transform: uppercase;
  color: var(--clr-ink-3);
  margin-top: 2px;
}

/* ── Desktop Menu ──────────────────────────────────────────────── */

.nav__menu {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

/* Individual nav item (wraps link + optional dropdown) */
.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: var(--weight-medium);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  color: var(--clr-ink-2);
  border-radius: var(--radius-sm);
  transition:
    color var(--dur-fast) var(--ease-out),
    background var(--dur-fast) var(--ease-out);
  white-space: nowrap;
}

.nav__link:hover,
.nav__item:hover > .nav__link {
  color: var(--clr-ink);
  background: var(--clr-accent-lt);
}

.nav__link.is-active {
  color: var(--clr-accent);
}

/* Down-chevron for items with dropdowns */
.nav__chevron {
  width: 10px;
  height: 10px;
  stroke: currentColor;
  stroke-width: 2;
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: transform var(--dur-fast) var(--ease-out);
  flex-shrink: 0;
}

.nav__item:hover > .nav__link .nav__chevron {
  transform: rotate(180deg);
}

/* ── Dropdowns ─────────────────────────────────────────────────── */

.nav__dropdown {
  position: absolute;
  top: calc(100% + 2px);   /* small gap below the link */
  left: 0;
  min-width: 210px;
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  padding: var(--space-2) 0;

  /* Hidden state */
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  pointer-events: none;
  transition:
    opacity var(--dur-mid) var(--ease-out),
    transform var(--dur-mid) var(--ease-out),
    visibility var(--dur-mid);
}

/* Show on parent hover */
.nav__item:hover > .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);
  font-weight: var(--weight-regular);
  color: var(--clr-ink-2);
  border-left: 2px solid transparent;
  transition:
    color var(--dur-fast) var(--ease-out),
    border-color var(--dur-fast) var(--ease-out),
    background var(--dur-fast) var(--ease-out);
}

.nav__dropdown-link:hover {
  color: var(--clr-accent);
  border-left-color: var(--clr-accent);
  background: var(--clr-accent-lt);
}

/* Optional divider inside a dropdown */
.nav__dropdown-divider {
  height: 1px;
  background: var(--clr-border);
  margin: var(--space-2) 0;
}

/* ── CTA Button (Donate) ───────────────────────────────────────── */

.nav__cta {
  display: inline-flex;
  align-items: center;
  padding: var(--space-2) var(--space-5);
  background: var(--clr-accent);
  color: var(--clr-on-accent);
  font-size: var(--text-sm);
  font-weight: var(--weight-semi);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  border-radius: var(--radius-sm);
  margin-left: var(--space-3);
  transition:
    background var(--dur-fast) var(--ease-out),
    transform var(--dur-fast) var(--ease-out);
}

.nav__cta:hover {
  background: var(--clr-accent-dk);
  transform: translateY(-1px);
}

.nav__cta:active {
  transform: translateY(0);
}

/* ── Mobile Toggle ─────────────────────────────────────────────── */

.nav__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  padding: var(--space-2);
  cursor: pointer;
  border-radius: var(--radius-sm);
  background: none;
  border: none;
  transition: background var(--dur-fast) var(--ease-out);
  flex-shrink: 0;
}

.nav__toggle:hover {
  background: var(--clr-accent-lt);
}

.nav__toggle-bar {
  display: block;
  width: 100%;
  height: 1.5px;
  background: var(--clr-ink);
  border-radius: 2px;
  transform-origin: center;
  transition:
    transform var(--dur-mid) var(--ease-out),
    opacity var(--dur-fast) var(--ease-out);
}

/* × icon when open */
.nav.is-open .nav__toggle-bar:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav.is-open .nav__toggle-bar:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav.is-open .nav__toggle-bar:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* ── Mobile Menu (drawer) ──────────────────────────────────────── */

@media (max-width: 900px) {

  .nav__toggle {
    display: flex;
  }

  /* Let the logo shrink/wrap instead of forcing the toggle off-screen */
  .nav__logo {
    flex-shrink: 1;
    min-width: 0;
  }

  .nav__logo-text {
    min-width: 0;
  }

  .nav__logo-primary {
    white-space: normal;
  }

  /* Hide desktop menu by default on mobile */
  .nav__menu {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--clr-surface);
    border-bottom: 1px solid var(--nav-border);
    box-shadow: var(--shadow-md);
    padding: var(--space-3) 0 var(--space-5);
    max-height: calc(100dvh - var(--nav-height));
    overflow-y: auto;
  }

  .nav.is-open .nav__menu {
    display: flex;
  }

  .nav__item {
    width: 100%;
  }

  .nav__link {
    width: 100%;
    padding: var(--space-3) var(--gutter);
    border-radius: 0;
    font-size: var(--text-base);
    letter-spacing: var(--tracking-wide);
  }

  /* Mobile dropdowns: show inline, indented */
  .nav__dropdown {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    pointer-events: auto;
    box-shadow: none;
    border: none;
    border-left: 2px solid var(--clr-border);
    border-radius: 0;
    background: transparent;
    padding: 0;
    /* Hidden until parent link is clicked */
    display: none;
    margin-left: var(--gutter);
  }

  .nav__item.is-open > .nav__dropdown {
    display: block;
  }

  .nav__dropdown-link {
    padding: var(--space-2) var(--space-5);
    border-left: none;
    font-size: var(--text-sm);
  }

  .nav__cta {
    margin: var(--space-3) var(--gutter) var(--space-2);
    align-self: flex-start;
  }
}