/* ================================================================
   NAVIGATION.CSS — Top Navigation Bar
   ================================================================ */

#nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  z-index: var(--z-nav);
  display: flex;
  align-items: center;
  transition:
    background var(--duration-mid) var(--ease-out),
    backdrop-filter var(--duration-mid) var(--ease-out),
    border-color var(--duration-mid) var(--ease-out),
    transform var(--duration-mid) var(--ease-out);
  border-bottom: 1px solid transparent;
}

/* Scrolled state → glassmorphism */
#nav.is-scrolled {
  background: rgba(238, 248, 249, 0.88);
  backdrop-filter: blur(20px) saturate(160%);
  -webkit-backdrop-filter: blur(20px) saturate(160%);
  border-bottom-color: rgba(79,124,130,0.18);
}

/* Hidden on scroll-down */
#nav.is-hidden {
  transform: translateY(-100%);
}

/* ── Nav Inner ── */
.nav-inner {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-pad);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* ── Logo ── */
.nav-logo {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  position: relative;
  display: inline-block;
}

.nav-logo-text {
  position: relative;
  z-index: 1;
  transition: opacity var(--duration-fast);
}

/* Glitch effect on hover */
.nav-logo:hover .nav-logo-text {
  animation: glitch 0.5s steps(3) forwards;
}

@keyframes glitch {
  0%   { transform: translate(0);        color: var(--text-primary); }
  20%  { transform: translate(-2px, 0);  color: var(--accent); }
  40%  { transform: translate(2px, 0);   color: var(--text-primary); text-shadow: -2px 0 rgba(79,124,130,0.6); }
  60%  { transform: translate(-1px, 0);  color: var(--accent); text-shadow: 2px 0 rgba(184,227,233,0.5); }
  80%  { transform: translate(1px, 0);   color: var(--text-primary); text-shadow: none; }
  100% { transform: translate(0);        color: var(--text-primary); text-shadow: none; }
}

/* ── Nav Links ── */
.nav-links {
  display: flex;
  align-items: center;
  gap: 2.5rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

/* li wraps each link — display:contents makes it invisible to flex layout */
.nav-links li {
  display: contents;
}

.nav-link {
  font-size: var(--fs-small);
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--text-secondary);
  position: relative;
  transition: color var(--duration-fast);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -3px;
  left: 50%;
  right: 50%;
  height: 1px;
  background: var(--accent);
  transition: left var(--duration-mid) var(--ease-out),
              right var(--duration-mid) var(--ease-out);
}

.nav-link:hover,
.nav-link.is-active {
  color: var(--text-primary);
}

.nav-link:hover::after,
.nav-link.is-active::after {
  left: 0;
  right: 0;
}

/* ── CTA Button ── */
.nav-cta {
  padding: 0.6rem 1.5rem;
  border: 1px solid var(--accent);
  border-radius: 100px;
  color: var(--accent);
  font-size: var(--fs-small);
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  transition: color var(--duration-mid) var(--ease-out);
  position: relative;
  overflow: hidden;
}

.nav-cta::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform var(--duration-mid) var(--ease-out);
}

.nav-cta:hover::before { transform: scaleX(1); }
.nav-cta:hover { color: #fff; }

.nav-cta span { position: relative; z-index: 1; }

/* ── Right-side controls group ── */
.nav-controls {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* ── Mobile Hamburger ── */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 28px;
}

.nav-hamburger span {
  height: 1.5px;
  background: var(--text-primary);
  transition: all var(--duration-mid) var(--ease-out);
  transform-origin: center;
}

.nav-hamburger.is-open span:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg);
}
.nav-hamburger.is-open span:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}
.nav-hamburger.is-open span:nth-child(3) {
  transform: translateY(-6.5px) rotate(-45deg);
}

/* ── Mobile Menu ── */
@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    inset: 0;
    background: var(--bg-primary);
    flex-direction: column;
    justify-content: center;
    gap: 2rem;
    transform: translateX(100%);
    transition: transform var(--duration-slow) var(--ease-out);
    z-index: calc(var(--z-nav) - 1);
  }

  .nav-links.is-open {
    transform: translateX(0);
  }

  .nav-link {
    font-size: 2rem;
    letter-spacing: -0.02em;
  }

  .nav-hamburger {
    display: flex;
  }

  .nav-cta {
    display: none;
  }
  .dark-mode-btn {
    width: 32px;
    height: 32px;
  }
}

/* ── Animation Toggle Switch ── */
.anim-toggle {
  position: relative;
  width: 50px;
  height: 26px;
  border-radius: 13px;
  background: var(--accent);
  border: none;
  cursor: none;
  transition: background 0.35s var(--ease-out);
  flex-shrink: 0;
}

/* OFF state — muted track */
body.reduce-motion .anim-toggle { background: var(--border-color); }

/* Sliding thumb */
.anim-toggle-thumb {
  position: absolute;
  top: 3px;
  right: 3px;          /* ON: thumb slides to right */
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: #fff;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: 2px;
  padding-bottom: 3px;
  transition: right 0.35s var(--ease-spring);
  box-shadow: 0 1px 4px rgba(0,0,0,0.18);
}

/* OFF: thumb slides to left */
body.reduce-motion .anim-toggle-thumb { right: 27px; }

/* Equalizer bars inside thumb */
.anim-bar {
  width: 2px;
  border-radius: 2px;
  background: var(--accent);
  transform-origin: bottom;
}

.b1 { height: 5px;  animation: eq-bar 1.0s ease-in-out infinite; }
.b2 { height: 9px;  animation: eq-bar 1.0s ease-in-out 0.2s infinite; }
.b3 { height: 6px;  animation: eq-bar 1.0s ease-in-out 0.4s infinite; }

@keyframes eq-bar {
  0%, 100% { transform: scaleY(1); }
  50%       { transform: scaleY(0.3); }
}

/* OFF — flat bars, no animation */
body.reduce-motion .anim-bar {
  animation: none;
  height: 2px !important;
  background: var(--border-color);
}

/* ── Dark Mode Toggle Button ── */
.dark-mode-btn {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--border-color);
  background: transparent;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--duration-mid) var(--ease-out);
  cursor: none;
  position: relative;
}
.dark-mode-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.dm-icon { display: none; }
.dm-icon--sun { display: block; }
body.dark-mode .dm-icon--sun  { display: none; }
body.dark-mode .dm-icon--moon { display: block; }

/* ── Mobile nav close button ── */
.nav-close-btn {
  display: none;
  position: absolute;
  top: 2rem;
  right: 2rem;
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  font-size: 1rem;
  cursor: none;
  transition: all var(--duration-fast);
}
.nav-close-btn:hover { border-color: var(--accent); color: var(--accent); }

@media (max-width: 768px) {
  .nav-close-btn { display: flex; align-items: center; justify-content: center; }
}