/* Phi marker navigation: custom chapter-shaped tab treatment. */
.main-nav {
  align-items: center;
  gap: clamp(0.25rem, 0.7vw, 0.6rem);
  overflow: visible;
}

.main-nav a {
  position: relative;
  isolation: isolate;
  display: grid !important;
  place-items: center;
  min-height: clamp(2.2rem, 3vw, 2.6rem) !important;
  padding: 0.48rem 0.35rem 0.32rem !important;
  border: 0;
  border-radius: 1.1rem;
  background: transparent;
  color: rgba(255, 255, 255, 0.82);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  line-height: 1.05;
  overflow: visible;
  text-align: center;
  text-shadow: 0 1px 8px rgba(0, 0, 0, 0.88);
  transform: translateZ(0);
  transition:
    color 0.25s ease,
    transform 0.28s cubic-bezier(0.22, 1, 0.36, 1),
    filter 0.28s ease;
}

.main-nav a::before {
  content: "";
  position: absolute;
  inset: -0.3rem 0.85rem -0.18rem;
  z-index: -1;
  background: url("assets/nav/the-phi-marker-gold.png") center / contain no-repeat;
  opacity: 0.58;
  filter:
    drop-shadow(0 0 0.45rem rgba(201, 154, 46, 0.12))
    drop-shadow(0 0.5rem 0.8rem rgba(0, 0, 0, 0.4));
  transform: rotate(-2deg) scale(0.9);
  transform-origin: center 58%;
  transition:
    opacity 0.28s ease,
    transform 0.28s cubic-bezier(0.22, 1, 0.36, 1),
    filter 0.28s ease;
}

.main-nav a::after {
  content: "";
  position: absolute;
  inset: 0.7rem 1.55rem 0.48rem 1.7rem;
  z-index: -2;
  border-radius: 999px;
  background:
    radial-gradient(circle at 40% 45%, rgba(240, 213, 143, 0.16), transparent 58%),
    rgba(201, 154, 46, 0.08);
  opacity: 0;
  transform: scale(0.72);
  transition:
    opacity 0.25s ease,
    transform 0.28s cubic-bezier(0.22, 1, 0.36, 1);
}

.main-nav a:hover,
.main-nav a:focus-visible {
  color: #ffffff;
  filter: saturate(1.08);
  transform: translateY(-2px) rotate(-0.5deg);
}

.main-nav a:hover::before,
.main-nav a:focus-visible::before {
  opacity: 0.88;
  filter:
    drop-shadow(0 0 0.7rem rgba(240, 213, 143, 0.22))
    drop-shadow(0 0.75rem 1rem rgba(0, 0, 0, 0.5));
  transform: rotate(0deg) scale(0.98);
}

.main-nav a:hover::after,
.main-nav a:focus-visible::after {
  opacity: 1;
  transform: scale(1);
}

.main-nav a[aria-selected="true"],
.main-nav a[aria-current="page"] {
  color: var(--gold-soft);
}

.main-nav a[aria-selected="true"]::before,
.main-nav a[aria-current="page"]::before {
  opacity: 1;
  filter:
    drop-shadow(0 0 0.75rem rgba(240, 213, 143, 0.32))
    drop-shadow(0 0.8rem 1rem rgba(0, 0, 0, 0.55));
  transform: rotate(0deg) scale(1);
}

.main-nav a[aria-selected="true"]::after,
.main-nav a[aria-current="page"]::after {
  opacity: 1;
  transform: scale(1);
}

@media (max-width: 840px) {
  .main-nav,
  html.force-mobile .main-nav {
    gap: 0.45rem 0.35rem;
  }

  .main-nav a,
  html.force-mobile .main-nav a {
    min-height: clamp(2.35rem, 8vw, 2.75rem) !important;
    padding: 0.5rem 0.12rem 0.32rem !important;
    font-size: 0.83rem;
  }

  .main-nav a::before,
  html.force-mobile .main-nav a::before {
    inset: -0.24rem 0.48rem -0.12rem;
  }

  .main-nav a::after,
  html.force-mobile .main-nav a::after {
    inset: 0.7rem 1rem 0.45rem 1.1rem;
  }
}

@media (max-width: 480px) {
  .main-nav a,
  html.force-mobile .main-nav a {
    min-height: 2.35rem !important;
    font-size: 0.83rem;
  }
}