#universe-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 70;
  transition: opacity var(--speed) ease;
}

.nav__inner {
  width: var(--shell);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--gap-md);
  padding: 1.4rem 0;
}

/*
 * The name in the header carries the same blend as the name on the landing
 * screen, but held back: a tighter ramp and a lower opacity, so it reads as
 * the quiet echo of the entrance rather than a second headline.
 */
.nav__brand {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.82rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  background: var(--blend-tight);
  background-size: 160% 100%;
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
  opacity: 0.82;
  transition: opacity var(--speed-fast) ease, background-position var(--speed-slow) var(--ease-out);
}

.nav__brand:hover,
.nav__brand:focus-visible {
  opacity: 1;
  background-position: 100% 50%;
}

.nav__list {
  display: flex;
  align-items: center;
  gap: clamp(0.9rem, 2vw, 2rem);
}

.nav__link {
  position: relative;
  padding: 0.3rem 0;
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-faint);
  transition: color var(--speed-fast) ease;
}

.nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 100%;
  bottom: 0;
  height: 1px;
  background: var(--violet);
  transition: right var(--speed) var(--ease-out);
}

.nav__link:hover,
.nav__link.is-active {
  color: var(--text-strong);
}

.nav__link.is-active::after {
  right: 0;
}

.nav__motion {
  font-size: 0.62rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-faint);
  transition: color var(--speed-fast) ease;
}

.nav__motion:hover,
.nav__motion[aria-pressed="true"] {
  color: var(--violet);
}

.nav__toggle {
  display: none;
  width: 34px;
  height: 34px;
  position: relative;
}

.nav__toggle span,
.nav__toggle span::before,
.nav__toggle span::after {
  position: absolute;
  left: 50%;
  width: 18px;
  height: 1px;
  background: var(--text);
  transform: translateX(-50%);
  transition: transform var(--speed-fast) var(--ease-out), opacity var(--speed-fast) ease;
}

.nav__toggle span {
  top: 50%;
}

.nav__toggle span::before {
  content: "";
  top: -6px;
}

.nav__toggle span::after {
  content: "";
  top: 6px;
}

#universe-nav.is-open .nav__toggle span {
  background: transparent;
}

#universe-nav.is-open .nav__toggle span::before {
  transform: translateX(-50%) translateY(6px) rotate(45deg);
}

#universe-nav.is-open .nav__toggle span::after {
  transform: translateX(-50%) translateY(-6px) rotate(-45deg);
}

/* Travel progress: the only chrome that reacts to the flight. */
.nav__progress {
  display: block;
  height: 1px;
  transform-origin: 0 50%;
  transform: scaleX(0);
  background: linear-gradient(90deg, var(--violet-deep), var(--violet), var(--amber));
  opacity: 0.7;
}