/* ============================================================
   NAV.CSS
   Fixed top navigation bar, logo, nav links, and the
   academic ↔ art profile toggle switch.
   ============================================================ */

nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 1.2rem 3rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  transition:
    background var(--theme-transition),
    border-color var(--theme-transition);
  backdrop-filter: blur(12px);
}

/* ── Logo ─────────────────────────────────────── */
.nav-logo {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--accent);
  transition: color var(--theme-transition), font-family 0.4s;
}

body.art-mode .nav-logo {
  font-family: var(--font-hand);
  font-size: 1.6rem;
}

/* ── Links ────────────────────────────────────── */
.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  transition: color var(--hover-transition);
}

.nav-links a:hover {
  color: var(--accent);
}

/* ── Toggle Wrapper ───────────────────────────── */
.toggle-wrapper {
  display: flex;
  align-items: center;
  gap: 0.8rem;
}

.toggle-label {
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  transition: color 0.4s, font-family 0.4s;
  font-family: var(--font-body);
  user-select: none;
}

body.art-mode .toggle-label.art-lbl {
  font-family: var(--font-hand);
  font-size: 0.95rem;
  color: var(--accent);
}

/* ── Toggle Switch Track & Thumb ──────────────── */
.toggle-switch {
  position: relative;
  width: 58px;
  height: 28px;
  cursor: pointer;
}

.toggle-switch input { display: none; }

.toggle-track {
  position: absolute;
  inset: 0;
  border-radius: 50px;
  background: var(--acad-card);
  border: 2px solid var(--acad-accent);
  transition: background 0.5s, border-color 0.5s;
  overflow: hidden;
}

/* Emoji icons inside track */
.toggle-track::before {
  content: '🎓';
  position: absolute;
  left: 4px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 0.7rem;
  transition: opacity 0.4s;
}

.toggle-track::after {
  content: '🎨';
  position: absolute;
  right: 4px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 0.7rem;
  opacity: 0.4;
  transition: opacity 0.4s;
}

.toggle-thumb {
  position: absolute;
  top: 3px;
  left: 3px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--acad-accent);
  transition:
    transform 0.45s cubic-bezier(0.34, 1.56, 0.64, 1),
    background 0.5s;
  z-index: 2;
}

/* ── Active (Art) State ───────────────────────── */
.toggle-switch.active .toggle-track {
  background: var(--art-bg);
  border-color: var(--art-accent);
}

.toggle-switch.active .toggle-track::before { opacity: 0.4; }
.toggle-switch.active .toggle-track::after  { opacity: 1; }

.toggle-switch.active .toggle-thumb {
  transform: translateX(30px);
  background: var(--art-accent);
}

/* ── Responsive ───────────────────────────────── */
@media (max-width: 768px) {
  nav { padding: 1rem 1.5rem; }
  .nav-links { display: none; }
}

/* ── Hamburger Button ─────────────────────────── */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
  background: none;
  border: none;
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
  transition: all 0.3s;
}

/* Animate to X when open */
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── Mobile Nav Menu ──────────────────────────── */
@media (max-width: 768px) {
  .hamburger { display: flex; }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 0.5rem 0;
    transition: background 0.7s, border-color 0.7s;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links li {
    width: 100%;
  }

  .nav-links a {
    display: block;
    padding: 0.85rem 2rem;
    border-bottom: 1px solid var(--border);
    font-size: 0.9rem;
  }

  .nav-links a:hover {
    background: var(--surface);
  }

  .toggle-wrapper {
    gap: 0.5rem;
  }

  .toggle-label {
    font-size: 0.65rem;
  }
}