.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding: 0.75rem 1.5rem;
  background: radial-gradient(circle at top left,
              rgba(84, 35, 130, 0.85) 0,
              rgba(10, 0, 17, 0.96) 45%,
              rgba(5, 0, 10, 1) 100%);
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

/* brand */

.brand a {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  font-size: 0.95rem;
  text-decoration: none;
  color: var(--text-main);
}

.brand a::before {
  content: "◎";
  font-size: 1.1rem;
  line-height: 1;
  color: var(--neon-teal);
  text-shadow:
    0 0 6px var(--neon-teal),
    0 0 12px var(--neon-teal);
}

/* nav layout */

.site-nav {
  margin-left: auto;
}

.site-nav ul {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 1.75rem;
  margin: 0;
  padding: 0;
}

.site-nav a {
  position: relative;
  font-size: 0.9rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--text-subtle);
  padding-bottom: 0.15rem;
  transition: color 0.15s ease-out;
}

.site-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--neon-pink), var(--neon-teal));
  box-shadow: 0 0 10px var(--neon-pink);
  transition: width 0.18s ease-out;
}

.site-nav a:hover {
  color: var(--text-main);
}

.site-nav a:hover::after,
.site-nav a[aria-current="page"]::after {
  width: 100%;
}

.site-nav a[aria-current="page"] {
  color: var(--neon-teal);
}

/* hamburger + mobile behavior */

.nav-toggle {
  display: none; /* hide checkbox itself */
}

.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  cursor: pointer;
  margin-left: auto;
}

.hamburger span {
  width: 22px;
  height: 2px;
  border-radius: 999px;
  background: var(--text-main);
  box-shadow: 0 0 6px rgba(255, 255, 255, 0.4);
  transition: transform 0.2s ease, opacity 0.2s ease;
}

/* responsive */

@media (max-width: 768px) {
  .site-header {
    padding: 0.65rem 1rem;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;
    background: rgba(10, 0, 17, 0.98);
    border-bottom: 1px solid rgba(255, 255, 255, 0.15);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.2s ease-out;
  }

  .site-nav ul {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.35rem;
    padding: 0.5rem 1.1rem 0.7rem;
  }

  .site-nav a {
    padding: 0.35rem 0;
  }

  .hamburger {
    display: flex;
  }

  /* when checked, drop nav down */
  .nav-toggle:checked ~ .hamburger span:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
  }

  .nav-toggle:checked ~ .hamburger span:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle:checked ~ .hamburger span:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
  }

  .nav-toggle:checked ~ .site-nav {
    max-height: 220px;
  }
}