/* ============================================
   NAV.CSS — Sticky Navigation
   ============================================ */

.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-height);

  /* Starts transparent, gains background on scroll */
  background: transparent;
  transition: background var(--transition-base),
              box-shadow var(--transition-base),
              backdrop-filter var(--transition-base);
}

/* Scrolled state — added via JS */
.site-nav.is-scrolled {
  background: rgba(250, 248, 245, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 var(--color-border);
}

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

/* ---- Logo / Name ---- */
.site-nav__logo {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.01em;
  text-decoration: none;
  transition: color var(--transition-fast);
  flex-shrink: 0;
}

.site-nav__logo:hover {
  color: var(--color-accent);
}

/* ---- Desktop Links ---- */
.site-nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-8);
  list-style: none;
}

.site-nav__links a {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  letter-spacing: 0.01em;
  padding: var(--space-1) 0;
  position: relative;
  transition: color var(--transition-fast);
}

/* Underline reveal on hover */
.site-nav__links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--color-accent);
  transition: width var(--transition-base);
}

.site-nav__links a:hover {
  color: var(--color-text);
}

.site-nav__links a:hover::after {
  width: 100%;
}

/* Active page indicator */
.site-nav__links a.is-active {
  color: var(--color-text);
}

.site-nav__links a.is-active::after {
  width: 100%;
  background: var(--color-accent);
}

/* ---- Hamburger (mobile) ---- */
.site-nav__hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 28px;
  height: 28px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 2px;
  z-index: 110;
}

.site-nav__hamburger span {
  display: block;
  height: 1.5px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base), width var(--transition-base);
  transform-origin: center;
}

/* Hamburger → X animation */
.site-nav__hamburger.is-open span:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg);
}
.site-nav__hamburger.is-open span:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}
.site-nav__hamburger.is-open span:nth-child(3) {
  transform: translateY(-6.5px) rotate(-45deg);
}

/* ---- Mobile Drawer ---- */
.site-nav__mobile {
  display: none;
  position: fixed;
  top: var(--nav-height);
  left: 0;
  right: 0;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-6) var(--space-6) var(--space-8);
  z-index: 99;

  /* Slide down animation */
  transform: translateY(-8px);
  opacity: 0;
  pointer-events: none;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.site-nav__mobile.is-open {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

.site-nav__mobile-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  list-style: none;
}

.site-nav__mobile-links a {
  display: block;
  font-size: var(--text-lg);
  font-weight: 500;
  color: var(--color-text-muted);
  padding: var(--space-3) 0;
  border-bottom: 1px solid var(--color-border-subtle);
  transition: color var(--transition-fast);
}

.site-nav__mobile-links a:hover,
.site-nav__mobile-links a.is-active {
  color: var(--color-text);
}

.site-nav__mobile-links li:last-child a {
  border-bottom: none;
}

/* ---- Responsive breakpoint ---- */
@media (max-width: 640px) {
  .site-nav__links {
    display: none;
  }

  .site-nav__hamburger {
    display: flex;
  }

  .site-nav__mobile {
    display: block;
  }
}

/* ---- Page offset for fixed nav ---- */
.nav-offset {
  padding-top: var(--nav-height);
}