/* ═══════════════════════════════════════════════════════════
   XEVRO — Cathedral of Sound
   Deep Frequency Spectrum Theme
   ═══════════════════════════════════════════════════════════ */

:root {
  --infinite-black: #0D0F14;
  --resonance-violet: #7A5CFF;
  --void-bg: #050608;
  --sonic-text: #F3F5F8;
  --electric-cyan: #3EF0D0;
  --sonic-purple: #9B4DFF;
  --infrared-magenta: #FF2D9B;
  --neon-indigo: #4B3FFF;
  --aurora-cyan: #2EE8C7;

  --font-heading: 'Space Grotesk', 'Syne', sans-serif;
  --font-display: 'Syne', 'Space Grotesk', sans-serif;
  --font-body: 'Inter', 'Manrope', sans-serif;

  --ease-resonance: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-pulse: cubic-bezier(0.45, 0, 0.55, 1);

  --nav-size: 52px;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font-body);
  background: var(--void-bg);
  color: var(--sonic-text);
  overflow-x: hidden;
  line-height: 1.6;
}

/* Accessibility */
.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  z-index: 10000;
  padding: 0.75rem 1.25rem;
  background: var(--resonance-violet);
  color: var(--sonic-text);
  text-decoration: none;
  border-radius: 4px;
  font-weight: 500;
  transition: top 0.2s;
}

.skip-link:focus {
  top: 1rem;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ═══ TYPOGRAPHY ═══ */
.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 5vw, 3.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, var(--sonic-text) 0%, var(--electric-cyan) 50%, var(--resonance-violet) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  text-align: center;
}

.section-subtitle {
  font-family: var(--font-body);
  font-size: clamp(0.875rem, 2vw, 1.125rem);
  color: rgba(243, 245, 248, 0.5);
  text-align: center;
  margin-top: 0.5rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

/* ═══ JOURNEY SECTIONS ═══ */
.journey-section {
  position: relative;
  min-height: 100vh;
  min-height: 100dvh;
  width: 100%;
  overflow: hidden;
}

.section-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

/* ═══ SONIC NAVIGATION ═══ */
.sonic-nav {
  position: fixed;
  top: 1.5rem;
  right: 1.5rem;
  z-index: 9000;
}

.tuning-fork {
  position: relative;
  width: var(--nav-size);
  height: var(--nav-size);
  border: none;
  background: rgba(13, 15, 20, 0.7);
  backdrop-filter: blur(12px);
  border-radius: 50%;
  cursor: pointer;
  color: var(--electric-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color 0.4s var(--ease-resonance), transform 0.4s var(--ease-resonance), box-shadow 0.4s;
  z-index: 2;
}

.tuning-fork:hover,
.tuning-fork[aria-expanded="true"] {
  color: var(--resonance-violet);
  box-shadow: 0 0 30px rgba(122, 92, 255, 0.4), 0 0 60px rgba(62, 240, 208, 0.15);
}

.tuning-fork[aria-expanded="true"] {
  transform: rotate(90deg);
}

.fork-icon {
  width: 22px;
  height: 32px;
}

.fork-glow {
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  border: 1px solid rgba(62, 240, 208, 0.2);
  animation: forkPulse 3s var(--ease-pulse) infinite;
}

@keyframes forkPulse {
  0%, 100% { transform: scale(1); opacity: 0.4; }
  50% { transform: scale(1.15); opacity: 0.8; }
}

.nav-menu {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0);
  width: min(90vw, 420px);
  height: min(90vw, 420px);
  opacity: 0;
  pointer-events: none;
  transition: transform 0.6s var(--ease-resonance), opacity 0.4s;
  z-index: 1;
}

.nav-menu.open {
  transform: translate(-50%, -50%) scale(1);
  opacity: 1;
  pointer-events: auto;
}

.nav-ring {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 1px solid rgba(122, 92, 255, 0.3);
  background: radial-gradient(circle, rgba(13, 15, 20, 0.95) 40%, rgba(122, 92, 255, 0.08) 100%);
  backdrop-filter: blur(20px);
  animation: navRingSpin 20s linear infinite;
}

@keyframes navRingSpin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.nav-frequencies {
  position: absolute;
  inset: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.25rem;
  padding: 2rem;
}

.nav-frequencies a {
  font-family: var(--font-heading);
  font-size: clamp(0.9rem, 2.5vw, 1.1rem);
  color: var(--sonic-text);
  text-decoration: none;
  padding: 0.6rem 1.5rem;
  border-radius: 2rem;
  transition: all 0.3s var(--ease-resonance);
  position: relative;
  letter-spacing: 0.08em;
}

.nav-frequencies a::before {
  content: attr(data-freq);
  position: absolute;
  left: -0.5rem;
  top: 50%;
  transform: translateY(-50%);
  font-size: 0.65rem;
  color: var(--electric-cyan);
  opacity: 0;
  transition: opacity 0.3s, left 0.3s;
}

.nav-frequencies a:hover,
.nav-frequencies a:focus-visible {
  color: var(--electric-cyan);
  background: rgba(122, 92, 255, 0.15);
  outline: none;
}

.nav-frequencies a:hover::before,
.nav-frequencies a:focus-visible::before {
  opacity: 0.6;
  left: 0.5rem;
}

.nav-particles {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  pointer-events: none;
}

.nav-overlay {
  position: fixed;
  inset: 0;
  background: rgba(5, 6, 8, 0.6);
  z-index: 8999;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s;
}

.nav-overlay.visible {
  opacity: 1;
  pointer-events: auto;
}

/* ═══ SECTION 1: FIRST VIBRATION ═══ */
.section-vibration {
  background: #000;
  display: flex;
  align-items: center;
  justify-content: center;
}

.vibration-core {
  position: relative;
  z-index: 2;
  width: 20px;
  height: 20px;
  transition: transform 0.1s linear;
}

.pulse-center {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  background: radial-gradient(circle, var(--electric-cyan) 0%, var(--resonance-violet) 60%, transparent 100%);
  box-shadow: 0 0 40px var(--electric-cyan), 0 0 80px var(--resonance-violet);
  animation: centerPulse 2s var(--ease-pulse) infinite;
}

@keyframes centerPulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.2); opacity: 0.8; }
}

.pulse-ring {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 40px;
  height: 40px;
  margin: -20px 0 0 -20px;
  border-radius: 50%;
  border: 1px solid rgba(62, 240, 208, 0.4);
  animation: rippleOut 3s var(--ease-resonance) infinite;
  animation-delay: var(--delay);
}

@keyframes rippleOut {
  0% { transform: scale(0.5); opacity: 1; }
  100% { transform: scale(8); opacity: 0; }
}

.materialize-layer {
  position: absolute;
  inset: 0;
  z-index: 1;
  opacity: 0;
  background:
    radial-gradient(ellipse at 50% 50%, rgba(122, 92, 255, 0.15) 0%, transparent 60%),
    radial-gradient(ellipse at 30% 70%, rgba(62, 240, 208, 0.08) 0%, transparent 50%),
    var(--void-bg);
  transition: opacity 0.3s linear;
}

.section-vibration.materialized .materialize-layer {
  opacity: 1;
}

.section-vibration.materialized .vibration-core {
  opacity: 0;
  transition: opacity 1s ease;
}

/* ═══ SECTION 2: CHAMBER OF ECHOES ═══ */
.section-echoes {
  background: linear-gradient(180deg, var(--void-bg) 0%, var(--infinite-black) 50%, var(--void-bg) 100%);
}

.echoes-atmosphere {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 40% at 50% 0%, rgba(122, 92, 255, 0.08) 0%, transparent 70%),
    radial-gradient(ellipse 60% 30% at 50% 100%, rgba(62, 240, 208, 0.05) 0%, transparent 60%);
  pointer-events: none;
}

.echo-hall {
  position: relative;
  z-index: 2;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 4rem 2rem;
  gap: 3rem;
}

.echoes-title {
  opacity: 0;
  transform: translateY(30px);
  transition: all 1s var(--ease-resonance);
}

.section-echoes.in-view .echoes-title {
  opacity: 1;
  transform: translateY(0);
}

.echo-waves {
  display: flex;
  flex-direction: column;
  gap: 4rem;
  width: 100%;
  max-width: 700px;
}

.echo-wave {
  position: relative;
  cursor: pointer;
  transition: transform 0.6s var(--ease-resonance);
}

.echo-wave .wave-surface {
  height: 80px;
  overflow: visible;
  opacity: 0.5;
  transition: opacity 0.5s, transform 0.6s var(--ease-resonance);
}

.echo-wave .wave-surface svg {
  width: 100%;
  height: 100%;
}

.echo-wave .wave-path {
  animation: waveDrift 4s ease-in-out infinite alternate;
}

.echo-wave:nth-child(2) .wave-path { animation-delay: -1.3s; }
.echo-wave:nth-child(3) .wave-path { animation-delay: -2.6s; }

@keyframes waveDrift {
  from { d: path("M0,40 Q25,10 50,40 T100,40 T150,40 T200,40"); }
  to { d: path("M0,40 Q25,60 50,40 T100,40 T150,20 T200,40"); }
}

.echo-wave .wave-content {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height 0.6s var(--ease-resonance), opacity 0.5s, padding 0.5s;
  padding: 0 1rem;
}

.echo-wave:hover .wave-surface,
.echo-wave:focus-visible .wave-surface,
.echo-wave.expanded .wave-surface {
  opacity: 1;
  transform: scaleY(1.5);
}

.echo-wave:hover .wave-content,
.echo-wave:focus-visible .wave-content,
.echo-wave.expanded .wave-content {
  max-height: 200px;
  opacity: 1;
  padding: 1.5rem 1rem;
}

.echo-wave .wave-content h3 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  color: var(--electric-cyan);
  margin-bottom: 0.5rem;
}

.echo-wave .wave-content p {
  font-size: 0.95rem;
  color: rgba(243, 245, 248, 0.7);
  line-height: 1.7;
}

.echo-wave:focus-visible {
  outline: 2px solid var(--resonance-violet);
  outline-offset: 4px;
  border-radius: 4px;
}

/* ═══ SECTION 3: FREQUENCY FOREST ═══ */
.section-forest {
  background: var(--void-bg);
}

.forest-header {
  position: absolute;
  top: 3rem;
  left: 0;
  right: 0;
  z-index: 3;
  pointer-events: none;
}

.forest-harmonics {
  position: absolute;
  bottom: 3rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 3;
  font-family: var(--font-heading);
  font-size: 0.85rem;
  letter-spacing: 0.2em;
  color: var(--electric-cyan);
  opacity: 0.7;
  text-transform: uppercase;
  pointer-events: none;
}

/* ═══ SECTION 4: ORCHESTRA OF PARTICLES ═══ */
.section-orchestra {
  background: var(--infinite-black);
}

.orchestra-content {
  position: absolute;
  inset: 0;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
}

.particle-reveal {
  position: absolute;
  max-width: 400px;
  text-align: center;
  opacity: 0;
  transform: translateY(20px) scale(0.95);
  transition: all 0.8s var(--ease-resonance);
  padding: 2rem;
}

.particle-reveal.active {
  opacity: 1;
  transform: translateY(0) scale(1);
}

.particle-reveal .reveal-title {
  font-family: var(--font-display);
  font-size: 2rem;
  margin-bottom: 1rem;
  color: var(--sonic-text);
}

.particle-reveal p {
  font-size: 0.95rem;
  color: rgba(243, 245, 248, 0.65);
  line-height: 1.8;
}

/* ═══ SECTION 5: RHYTHM ENGINE ═══ */
.section-rhythm {
  background: radial-gradient(ellipse at center, #0a0c12 0%, var(--void-bg) 70%);
  display: flex;
  align-items: center;
  justify-content: center;
}

.rhythm-chamber {
  text-align: center;
  padding: 2rem;
  z-index: 2;
}

.rhythm-title {
  margin-bottom: 3rem;
}

.rhythm-machine {
  position: relative;
  width: min(80vw, 500px);
  height: min(80vw, 500px);
  margin: 0 auto 2rem;
}

.rhythm-ring {
  position: absolute;
  top: 50%;
  left: 50%;
  border-radius: 50%;
  border: 2px solid;
  transform: translate(-50%, -50%);
  animation: ringRotate var(--speed, 12s) linear infinite;
}

.rhythm-ring[data-ring="creativity"] {
  width: 90%; height: 90%;
  border-color: rgba(122, 92, 255, 0.4);
  --speed: 20s;
  animation-direction: reverse;
}

.rhythm-ring[data-ring="energy"] {
  width: 72%; height: 72%;
  border-color: rgba(62, 240, 208, 0.35);
  --speed: 15s;
}

.rhythm-ring[data-ring="motion"] {
  width: 54%; height: 54%;
  border-color: rgba(255, 45, 155, 0.3);
  --speed: 10s;
  animation-direction: reverse;
}

.rhythm-ring[data-ring="expression"] {
  width: 36%; height: 36%;
  border-color: rgba(75, 63, 255, 0.4);
  --speed: 8s;
}

.rhythm-ring[data-ring="innovation"] {
  width: 18%; height: 18%;
  border-color: rgba(62, 240, 208, 0.5);
  --speed: 5s;
  animation-direction: reverse;
}

@keyframes ringRotate {
  from { transform: translate(-50%, -50%) rotate(0deg); }
  to { transform: translate(-50%, -50%) rotate(360deg); }
}

.rhythm-ring::after {
  content: '';
  position: absolute;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: currentColor;
  top: -4px;
  left: 50%;
  margin-left: -4px;
  box-shadow: 0 0 12px currentColor;
}

.rhythm-ring[data-ring="creativity"] { color: var(--resonance-violet); }
.rhythm-ring[data-ring="energy"] { color: var(--electric-cyan); }
.rhythm-ring[data-ring="motion"] { color: var(--infrared-magenta); }
.rhythm-ring[data-ring="expression"] { color: var(--neon-indigo); }
.rhythm-ring[data-ring="innovation"] { color: var(--aurora-cyan); }

.ring-label {
  position: absolute;
  bottom: -1.5rem;
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--font-heading);
  font-size: 0.7rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: rgba(243, 245, 248, 0.5);
  white-space: nowrap;
  opacity: 0;
  transition: opacity 0.3s;
}

.rhythm-ring:hover .ring-label {
  opacity: 1;
}

.rhythm-core {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 40px;
  height: 40px;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  background: radial-gradient(circle, var(--electric-cyan), var(--resonance-violet));
  box-shadow: 0 0 40px rgba(122, 92, 255, 0.6);
  animation: coreBeat 1.2s var(--ease-pulse) infinite;
}

@keyframes coreBeat {
  0%, 100% { transform: translate(-50%, -50%) scale(1); }
  15% { transform: translate(-50%, -50%) scale(1.3); }
  30% { transform: translate(-50%, -50%) scale(1); }
  45% { transform: translate(-50%, -50%) scale(1.15); }
}

.rhythm-desc {
  max-width: 500px;
  margin: 0 auto;
  font-size: 0.95rem;
  color: rgba(243, 245, 248, 0.55);
  line-height: 1.8;
}

/* ═══ SECTION 6: CANYON OF BASS ═══ */
.section-canyon {
  background: linear-gradient(180deg, #0a0806 0%, #050302 50%, #080604 100%);
}

.canyon-content {
  position: absolute;
  bottom: 15%;
  left: 50%;
  transform: translateX(-50%);
  z-index: 3;
  text-align: center;
  padding: 0 2rem;
  max-width: 600px;
}

.canyon-title {
  margin-bottom: 1rem;
}

.canyon-text {
  font-size: 0.95rem;
  color: rgba(243, 245, 248, 0.6);
  margin-bottom: 2rem;
}

.bass-pulse-indicator {
  display: flex;
  gap: 6px;
  justify-content: center;
  align-items: flex-end;
  height: 40px;
}

.bass-bar {
  width: 6px;
  background: linear-gradient(to top, var(--resonance-violet), var(--infrared-magenta));
  border-radius: 3px;
  animation: bassBar 0.8s var(--ease-pulse) infinite;
}

.bass-bar:nth-child(1) { animation-delay: 0s; height: 20%; }
.bass-bar:nth-child(2) { animation-delay: 0.15s; height: 40%; }
.bass-bar:nth-child(3) { animation-delay: 0.3s; height: 60%; }
.bass-bar:nth-child(4) { animation-delay: 0.45s; height: 40%; }
.bass-bar:nth-child(5) { animation-delay: 0.6s; height: 20%; }

@keyframes bassBar {
  0%, 100% { transform: scaleY(0.4); opacity: 0.5; }
  50% { transform: scaleY(1); opacity: 1; }
}

/* ═══ SECTION 7: SKY OF HARMONICS ═══ */
.section-sky {
  background: linear-gradient(180deg, var(--void-bg) 0%, #0a0e18 40%, #12182a 100%);
}

.sky-content {
  position: absolute;
  top: 3rem;
  left: 0;
  right: 0;
  z-index: 3;
  text-align: center;
  padding: 0 2rem;
  pointer-events: none;
}

.harmonic-stories {
  margin-top: 2rem;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

.harmonic-story {
  opacity: 0;
  transform: translateY(15px);
  transition: all 0.8s var(--ease-resonance);
  padding: 1rem;
}

.harmonic-story.visible {
  opacity: 1;
  transform: translateY(0);
}

.harmonic-story p {
  font-size: 0.9rem;
  color: rgba(243, 245, 248, 0.6);
  font-style: italic;
}

/* ═══ SECTION 8: ARCHIVE OF VOICES ═══ */
.section-voices {
  background: radial-gradient(ellipse at 50% 30%, #0e1020 0%, var(--void-bg) 70%);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 4rem 1rem;
  min-height: 100vh;
  min-height: 100dvh;
}

.archive-header {
  margin-bottom: 2rem;
  z-index: 2;
}

.sphere-field {
  position: relative;
  width: 100%;
  max-width: 900px;
  height: 60vh;
  z-index: 2;
}

.voice-sphere {
  position: absolute;
  width: var(--size, 40px);
  height: var(--size, 40px);
  border-radius: 50%;
  border: none;
  cursor: pointer;
  background: radial-gradient(circle at 30% 30%,
    rgba(255, 255, 255, 0.3) 0%,
    rgba(122, 92, 255, 0.4) 30%,
    rgba(62, 240, 208, 0.2) 70%,
    transparent 100%);
  box-shadow:
    inset 0 0 15px rgba(255, 255, 255, 0.1),
    0 0 20px rgba(122, 92, 255, 0.3);
  transition: transform 0.4s var(--ease-resonance), box-shadow 0.4s;
  animation: sphereFloat var(--float-dur, 6s) ease-in-out infinite;
  animation-delay: var(--float-delay, 0s);
}

.voice-sphere:hover,
.voice-sphere:focus-visible {
  transform: scale(1.4);
  box-shadow:
    inset 0 0 20px rgba(255, 255, 255, 0.2),
    0 0 40px rgba(62, 240, 208, 0.5);
  outline: none;
}

@keyframes sphereFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}

.sphere-detail {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0.9);
  z-index: 8000;
  background: rgba(13, 15, 20, 0.92);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(122, 92, 255, 0.3);
  border-radius: 16px;
  padding: 2.5rem;
  max-width: 420px;
  width: 90%;
  opacity: 0;
  pointer-events: none;
  transition: all 0.5s var(--ease-resonance);
}

.sphere-detail.open {
  opacity: 1;
  transform: translate(-50%, -50%) scale(1);
  pointer-events: auto;
}

.sphere-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: none;
  border: none;
  color: var(--sonic-text);
  font-size: 1.5rem;
  cursor: pointer;
  opacity: 0.5;
  transition: opacity 0.2s;
}

.sphere-close:hover { opacity: 1; }

.sphere-detail h3 {
  font-family: var(--font-heading);
  color: var(--electric-cyan);
  margin-bottom: 1rem;
  font-size: 1.3rem;
}

.sphere-detail p {
  color: rgba(243, 245, 248, 0.75);
  line-height: 1.7;
  font-size: 0.95rem;
}

.sphere-pattern {
  margin-top: 1.5rem;
  height: 60px;
  background: repeating-linear-gradient(
    90deg,
    transparent,
    transparent 8px,
    rgba(62, 240, 208, 0.15) 8px,
    rgba(62, 240, 208, 0.15) 10px
  );
  border-radius: 4px;
  animation: patternShift 2s linear infinite;
}

@keyframes patternShift {
  from { background-position: 0 0; }
  to { background-position: 20px 0; }
}

/* ═══ SECTION 9: RESONANCE TOWER ═══ */
.section-tower {
  background: var(--void-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 4rem 2rem;
}

.tower-container {
  position: relative;
  width: 100%;
  max-width: 500px;
  z-index: 2;
}

.tower-title {
  margin-bottom: 3rem;
}

.tower-structure {
  display: flex;
  flex-direction: column-reverse;
  gap: 0;
  position: relative;
}

.tower-level {
  position: relative;
  padding: 2rem 1.5rem;
  border-left: 3px solid rgba(122, 92, 255, 0.2);
  margin-left: 2rem;
  opacity: 0.4;
  transition: all 0.6s var(--ease-resonance);
  cursor: default;
}

.tower-level::before {
  content: '';
  position: absolute;
  left: -8px;
  top: 50%;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--infinite-black);
  border: 2px solid rgba(122, 92, 255, 0.3);
  transform: translateY(-50%);
  transition: all 0.4s;
}

.tower-level.active,
.tower-level:hover {
  opacity: 1;
  border-left-color: var(--resonance-violet);
}

.tower-level.active::before,
.tower-level:hover::before {
  background: var(--resonance-violet);
  box-shadow: 0 0 20px var(--resonance-violet);
}

.level-name {
  font-family: var(--font-heading);
  font-size: 1rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--electric-cyan);
  display: block;
  margin-bottom: 0.5rem;
}

.level-desc {
  font-size: 0.85rem;
  color: rgba(243, 245, 248, 0.55);
  line-height: 1.6;
}

.tower-energy {
  position: absolute;
  left: 2rem;
  bottom: 0;
  width: 3px;
  background: linear-gradient(to top, var(--electric-cyan), var(--resonance-violet), transparent);
  transition: height 0.8s var(--ease-resonance);
  box-shadow: 0 0 15px var(--resonance-violet);
  border-radius: 2px;
}

/* ═══ SECTION 10: FINAL NOTE ═══ */
.section-final {
  background: var(--void-bg);
  display: flex;
  align-items: center;
  justify-content: center;
}

.final-chamber {
  position: relative;
  width: 100%;
  height: 100vh;
  height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.convergence-rings {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
}

.conv-ring {
  position: absolute;
  border-radius: 50%;
  border: 1px solid rgba(122, 92, 255, 0.15);
  animation: convPulse 4s var(--ease-pulse) infinite;
}

.conv-ring:nth-child(1) { width: 60vmin; height: 60vmin; animation-delay: 0s; }
.conv-ring:nth-child(2) { width: 75vmin; height: 75vmin; animation-delay: 1.3s; }
.conv-ring:nth-child(3) { width: 90vmin; height: 90vmin; animation-delay: 2.6s; }

@keyframes convPulse {
  0%, 100% { opacity: 0.2; transform: scale(0.98); }
  50% { opacity: 0.5; transform: scale(1.02); }
}

.final-silence {
  position: absolute;
  inset: 0;
  background: #000;
  opacity: 1;
  transition: opacity 2s ease;
  z-index: 3;
  pointer-events: none;
}

.final-silence.dissolved {
  opacity: 0;
}

.final-reveal {
  position: relative;
  z-index: 4;
  text-align: center;
  opacity: 0;
  transform: scale(0.9);
  transition: all 1.5s var(--ease-resonance);
  padding: 2rem;
}

.final-reveal.visible {
  opacity: 1;
  transform: scale(1);
}

.final-headline {
  font-family: var(--font-display);
  font-size: clamp(2rem, 7vw, 4.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 3rem;
  background: linear-gradient(135deg, var(--sonic-text), var(--electric-cyan), var(--resonance-violet));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.resonance-core-wrap {
  display: flex;
  justify-content: center;
}

.resonance-core {
  position: relative;
  width: 180px;
  height: 180px;
  border: none;
  border-radius: 50%;
  background: transparent;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

.core-inner {
  position: absolute;
  inset: 20%;
  border-radius: 50%;
  background: radial-gradient(circle, var(--electric-cyan) 0%, var(--resonance-violet) 50%, transparent 80%);
  box-shadow: 0 0 60px rgba(122, 92, 255, 0.5);
  transition: transform 0.4s var(--ease-resonance), box-shadow 0.4s;
}

.resonance-core:hover .core-inner,
.resonance-core:focus-visible .core-inner {
  transform: scale(1.15);
  box-shadow: 0 0 80px rgba(62, 240, 208, 0.6), 0 0 120px rgba(122, 92, 255, 0.4);
}

.core-waves {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 1px solid rgba(62, 240, 208, 0.3);
  animation: coreWave 2s var(--ease-pulse) infinite;
}

.resonance-core:hover .core-waves {
  animation-duration: 0.8s;
}

@keyframes coreWave {
  0% { transform: scale(1); opacity: 0.6; }
  100% { transform: scale(1.6); opacity: 0; }
}

.core-label {
  position: relative;
  z-index: 1;
  font-family: var(--font-heading);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  color: var(--sonic-text);
  text-shadow: 0 0 20px rgba(0, 0, 0, 0.8);
}

.resonance-core:focus-visible {
  outline: 2px solid var(--electric-cyan);
  outline-offset: 8px;
}

/* ═══ RESPONSIVE ═══ */
@media (max-width: 768px) {
  .sonic-nav {
    top: 1rem;
    right: 1rem;
  }

  .echo-waves {
    gap: 2.5rem;
  }

  .rhythm-machine {
    width: 85vw;
    height: 85vw;
  }

  .ring-label {
    display: none;
  }

  .sphere-field {
    height: 50vh;
  }

  .tower-level {
    padding: 1.5rem 1rem;
    margin-left: 1.5rem;
  }

  .resonance-core {
    width: 150px;
    height: 150px;
  }
}

@media (max-width: 480px) {
  .nav-menu {
    width: 95vw;
    height: 95vw;
  }

  .final-headline {
    font-size: 1.75rem;
  }
}