/* ============================================================
   HEADER / NAVIGATION — Fixed top bar + bottom nav cluster
   ============================================================ */

/* ─── Grain Overlay ─── */
#grain-overlay {
  position: fixed;
  inset: 0;
  z-index: var(--z-cursor);
  pointer-events: none;
  opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 128px 128px;
}

/* ─── Top Header Bar ─── */
#site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-h);
  z-index: var(--z-nav);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding: 0 var(--sp-8);
  pointer-events: none;
}

/* ─── Tagline (left) ─── */
.header-tagline {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 300;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-3);
  transform: rotate(-15deg) translateY(4px);
  transform-origin: left center;
  pointer-events: none;
  user-select: none;
  white-space: nowrap;
}

/* ─── Logo (center) ─── */
.header-logo {
  justify-self: center;
  pointer-events: all;
  text-decoration: none;
}

.logo-wordmark {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 400;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ink);
  display: block;
  transition: opacity var(--dur-base) var(--ease-smooth);
}

.header-logo:hover .logo-wordmark { opacity: 0.5; }

/* ─── Social links (right) ─── */
.social-links {
  justify-self: end;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.3rem;
  pointer-events: all;
}

.social-links a {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 300;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-3);
  transition: color var(--dur-base) var(--ease-smooth);
  white-space: nowrap;
}

.social-links a:hover { color: var(--ink); }

/* ─── Corner Tagline (left side vertical) ─── */
.corner-tagline {
  position: fixed;
  left: -3.5rem;
  top: 50%;
  transform: translateY(-50%) rotate(-90deg);
  transform-origin: center center;
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 300;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-4);
  pointer-events: none;
  user-select: none;
  white-space: nowrap;
  z-index: var(--z-nav);
}

/* ─── Bottom Navigation ─── */
#arc-nav {
  position: fixed;
  bottom: var(--sp-8);
  left: 0;
  right: 0;
  z-index: var(--z-nav);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(1.5rem, 4vw, 4rem);
  pointer-events: none;
}

#nav-needle { display: none; }

.nav-link {
  font-family: var(--font-display);
  font-size: clamp(0.8rem, 1.2vw, 1rem);
  font-weight: 300;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink);
  opacity: 0.35;
  pointer-events: all;
  transition: opacity var(--dur-base) var(--ease-smooth),
              font-size var(--dur-slow) var(--ease-expo);
  white-space: nowrap;
}

.nav-link:hover { opacity: 0.7; }

.nav-link.active {
  opacity: 1;
  font-size: clamp(1.4rem, 2.5vw, 2.2rem);
  font-weight: 400;
}

.nav-link.adj-1 { opacity: 0.55; font-size: clamp(0.9rem, 1.5vw, 1.3rem); }
.nav-link.adj-2 { opacity: 0.4;  font-size: clamp(0.75rem, 1.1vw, 0.95rem); }

/* ─── Footer bar ─── */
#site-footer-bar {
  position: fixed;
  bottom: var(--sp-4);
  left: var(--sp-8);
  right: var(--sp-8);
  display: flex;
  align-items: center;
  justify-content: space-between;
  pointer-events: none;
  z-index: calc(var(--z-nav) - 1);
}

.footer-copy,
.footer-credit {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 300;
  letter-spacing: 0.08em;
  color: var(--ink-4);
}

/* ─── Theme Toggle ─── */
#theme-toggle {
  position: fixed;
  top: 50%;
  right: var(--sp-6);
  transform: translateY(-50%);
  z-index: var(--z-nav);
  width: 2rem;
  height: 2rem;
  border-radius: var(--r-full);
  border: 1px solid var(--border);
  background: var(--bg);
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: all;
  transition: border-color var(--dur-base) var(--ease-smooth),
              box-shadow var(--dur-base) var(--ease-smooth);
  backdrop-filter: blur(12px);
}

#theme-toggle:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md);
}

#theme-toggle svg {
  width: 14px;
  height: 14px;
  color: var(--ink-3);
  transition: color var(--dur-base) var(--ease-smooth);
}

#theme-toggle:hover svg { color: var(--ink); }

/* ─── Hamburger ─── */
#hamburger {
  display: none;
  position: fixed;
  top: 50%;
  transform: translateY(-50%);
  right: var(--sp-6);
  z-index: var(--z-overlay);
  width: 2.5rem;
  height: 2.5rem;
  flex-direction: column;
  justify-content: center;
  align-items: flex-end;
  gap: 5px;
  pointer-events: all;
}

#hamburger span {
  display: block;
  height: 1px;
  background: var(--ink);
  transition: all var(--dur-base) var(--ease-in-out);
  transform-origin: right center;
}

#hamburger span:nth-child(1) { width: 1.5rem; }
#hamburger span:nth-child(2) { width: 1rem; }
#hamburger span:nth-child(3) { width: 1.5rem; }

#hamburger.open span:nth-child(1) { transform: translateY(6px) rotate(-45deg); width: 1.5rem; }
#hamburger.open span:nth-child(2) { opacity: 0; width: 0; }
#hamburger.open span:nth-child(3) { transform: translateY(-6px) rotate(45deg); width: 1.5rem; }

/* ─── Mobile Menu ─── */
#mobile-menu {
  position: fixed;
  inset: 0;
  z-index: calc(var(--z-overlay) - 1);
  background: rgba(10,10,15,0.95);
  backdrop-filter: blur(24px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--sp-8);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--dur-slow) var(--ease-smooth);
}

#mobile-menu.open {
  opacity: 1;
  pointer-events: all;
}

.mobile-nav-link {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 10vw, 4.5rem);
  font-weight: 300;
  color: var(--ink-3);
  letter-spacing: -0.01em;
  opacity: 0;
  transform: translateY(24px);
  transition: color var(--dur-base) var(--ease-smooth),
              opacity var(--dur-slow) var(--ease-expo),
              transform var(--dur-slow) var(--ease-expo);
}

#mobile-menu.open .mobile-nav-link {
  opacity: 1;
  transform: translateY(0);
}

#mobile-menu.open .mobile-nav-link:nth-child(1) { transition-delay: 0.05s; }
#mobile-menu.open .mobile-nav-link:nth-child(2) { transition-delay: 0.10s; }
#mobile-menu.open .mobile-nav-link:nth-child(3) { transition-delay: 0.15s; }
#mobile-menu.open .mobile-nav-link:nth-child(4) { transition-delay: 0.20s; }
#mobile-menu.open .mobile-nav-link:nth-child(5) { transition-delay: 0.25s; }

.mobile-nav-link:hover,
.mobile-nav-link.active { color: var(--ink); }