/* ════════════════════════
   VELTRIX — NAVIGATION
   ════════════════════════ */
#nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-h);
  z-index: var(--z-nav);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--sp-8);
  transition: background var(--dur-mid), backdrop-filter var(--dur-mid), border-color var(--dur-mid);
  border-bottom: 1px solid transparent;
}

#nav.scrolled {
  background: rgba(9, 9, 11, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-color: var(--ice-border);
}

/* Logo */
.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  cursor: none;
}

.logo-mark {
  font-size: 1.4rem;
  color: var(--amber);
  filter: drop-shadow(0 0 8px rgba(245, 179, 1, 0.4));
  transition: filter var(--dur-mid);
}
.nav-logo:hover .logo-mark {
  filter: drop-shadow(0 0 14px rgba(245, 179, 1, 0.7));
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1;
  gap: 2px;
}

.logo-veltrix {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--ice);
}

.logo-tech {
  font-family: var(--font-mono);
  font-size: 0.5rem;
  letter-spacing: 0.22em;
  color: var(--amber);
  opacity: 0.8;
}

/* Nav links */
.nav-links {
  display: flex;
  align-items: center;
  gap: var(--sp-8);
}

.nav-link {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  color: var(--ice-dim);
  transition: color var(--dur-fast);
  position: relative;
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--amber);
  transition: width var(--dur-mid) var(--ease-out);
}
.nav-link:hover {
  color: var(--ice);
}
.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}
.nav-link.active {
  color: var(--amber);
}

/* CTA button */
.btn-nav-cta {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--obsidian);
  background: var(--amber);
  padding: var(--sp-2) var(--sp-4);
  border-radius: var(--r-sm);
  font-weight: 600;
  transition: background var(--dur-fast), transform var(--dur-fast), box-shadow var(--dur-fast);
}
.btn-nav-cta:hover {
  background: var(--amber-soft);
  transform: translateY(-1px);
  box-shadow: 0 4px 20px rgba(245, 179, 1, 0.35);
}

/* Burger */
.nav-burger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
  cursor: none;
}
.nav-burger span {
  display: block;
  width: 24px;
  height: 1.5px;
  background: var(--ice);
  border-radius: var(--r-full);
  transition: transform var(--dur-mid) var(--ease-out),
              opacity var(--dur-fast);
}
.nav-burger.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav-burger.open span:nth-child(2) { opacity: 0; }
.nav-burger.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* Mobile menu */
#mobile-menu {
  position: fixed;
  inset: 0;
  z-index: calc(var(--z-nav) - 1);
  background: rgba(9, 9, 11, 0.97);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--dur-mid) var(--ease-out);
}
#mobile-menu.open {
  opacity: 1;
  pointer-events: all;
}

.mobile-menu-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--sp-8);
}

.mobile-link {
  font-family: var(--font-display);
  font-size: 1.4rem;
  letter-spacing: 0.08em;
  color: var(--ice-dim);
  transition: color var(--dur-fast);
}
.mobile-link:hover {
  color: var(--amber);
}
.mobile-cta {
  margin-top: var(--sp-4);
  color: var(--amber);
  border: 1px solid var(--amber-border);
  padding: var(--sp-3) var(--sp-8);
  border-radius: var(--r-sm);
}