/* =============================================================
   SHARED NAVIGATION & FOOTER — nav.css
   Loaded on every page. Uses design tokens from style.css :root.
   ============================================================= */

/* --- Fixed nav body offset --- */
body.has-nav {
  padding-top: 64px;
}


/* =============================================================
   SITE HEADER
   ============================================================= */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 200;
  transition:
    background-color var(--transition-base),
    border-color var(--transition-base);
  border-bottom: 1px solid transparent;
}

.site-header.scrolled {
  background-color: rgba(22, 22, 22, 0.92);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom-color: var(--border);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

/* --- Brand / Logo --- */
.nav-brand {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  text-decoration: none;
  flex-shrink: 0;
  transition: color var(--transition-fast);
}

.nav-brand:hover {
  color: var(--accent);
}

/* --- Nav links list --- */
.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  padding: 0.5rem 0.875rem;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  border: 1px solid transparent;
  transition:
    color var(--transition-fast),
    background-color var(--transition-fast),
    border-color var(--transition-fast);
}

.nav-link:hover,
.nav-link[aria-current="page"] {
  color: var(--text-primary);
  background-color: var(--bg-card);
  border-color: var(--border);
}

.nav-link:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

/* --- Hamburger toggle (hidden on desktop) --- */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 8px;
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  cursor: pointer;
  flex-shrink: 0;
  transition: border-color var(--transition-fast);
}

.nav-toggle:hover {
  border-color: var(--border-hover);
}

.nav-toggle .bar {
  display: block;
  width: 18px;
  height: 2px;
  background-color: var(--text-secondary);
  border-radius: 2px;
  pointer-events: none;
  transition:
    transform var(--transition-base),
    opacity var(--transition-fast);
}

.nav-toggle[aria-expanded="true"] .bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* --- Tablet: tighten link spacing so the row doesn't overflow --- */
@media (max-width: 1024px) {
  .nav-link {
    padding: 0.4rem 0.6rem;
    font-size: 0.85rem;
  }
}

/* --- Mobile layout --- */
@media (max-width: 640px) {
  .nav-toggle { display: flex; }

  .nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-lg) var(--space-md);
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
  }

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

  .nav-link {
    padding: 0.75rem 1rem;
    border-color: var(--border);
    background-color: var(--bg-card);
  }
}


/* =============================================================
   SITE FOOTER
   ============================================================= */
.site-footer {
  padding: var(--space-2xl) 0 var(--space-xl);
  border-top: 1px solid var(--border);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
  text-align: center;
}

.footer-copy {
  font-size: 0.875rem;
  color: var(--text-muted);
  max-width: none;
  line-height: 1.5;
  margin: 0;
}

.footer-socials {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
}

.footer-socials a {
  display: flex;
  align-items: center;
  color: var(--text-secondary);
  transition:
    color var(--transition-fast),
    transform var(--transition-fast);
}

.footer-socials a:hover {
  color: var(--accent);
  transform: translateY(-2px);
}

.footer-tagline {
  font-size: 0.8rem;
  color: var(--text-muted);
  max-width: none;
  margin: 0;
}


/* =============================================================
   BACK TO TOP BUTTON
   ============================================================= */
.back-to-top {
  position: fixed;
  bottom: var(--space-xl);
  right: var(--space-xl);
  z-index: 150;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background-color: var(--bg-card);
  color: var(--text-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition:
    opacity var(--transition-base),
    transform var(--transition-base),
    color var(--transition-fast),
    border-color var(--transition-fast),
    background-color var(--transition-fast);
}

.back-to-top.visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.back-to-top:hover {
  color: var(--accent);
  border-color: var(--accent);
  background-color: var(--accent-soft);
}

@media (max-width: 640px) {
  .back-to-top {
    bottom: var(--space-lg);
    right: var(--space-lg);
  }
}