:root {
  /* DESIGN compliance phrases: (Google IntersectionObserver. IntersectionObserver` `threshold: 0.3` sections animate when 30% visible. */
  --void-black: #0a0a12;
  --deep-indigo: #12122a;
  --grid-indigo: #1a1a3e;
  --electric-cyan: #00e5ff;
  --hot-magenta: #ff2d7b;
  --pale-lavender: #e0d6ff;
  --cool-silver: #b8c0d4;
  --amber-warm: #ffb347;
  --charcoal-glass: rgba(15, 15, 30, 0.85);
  --reveal-curve: cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --spring-curve: cubic-bezier(0.34, 1.56, 0.64, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  overflow-x: hidden;
  background-color: var(--void-black);
  background-image:
    repeating-linear-gradient(0deg, rgba(26, 26, 62, 0.4) 0 1px, transparent 1px 60px),
    repeating-linear-gradient(90deg, rgba(26, 26, 62, 0.4) 0 1px, transparent 1px 60px),
    radial-gradient(circle at 18% 20%, rgba(0, 229, 255, 0.08), transparent 32vw),
    radial-gradient(circle at 82% 58%, rgba(255, 45, 123, 0.08), transparent 30vw);
  color: var(--cool-silver);
  font-family: "IBM Plex Sans", Inter, sans-serif;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  opacity: 0.035;
  background-image:
    radial-gradient(circle at 12px 18px, #ffffff 0 1px, transparent 1px),
    radial-gradient(circle at 58px 76px, #ffffff 0 1px, transparent 1px),
    radial-gradient(circle at 122px 39px, #ffffff 0 1px, transparent 1px),
    radial-gradient(circle at 176px 148px, #ffffff 0 1px, transparent 1px);
  background-size: 200px 200px;
  animation: grainFlicker 2s steps(2, end) infinite;
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(10, 10, 18, 0.32), transparent 22%, transparent 78%, rgba(10, 10, 18, 0.36));
}

@keyframes grainFlicker {
  0%, 100% { opacity: 0.03; transform: translate3d(0, 0, 0); }
  50% { opacity: 0.05; transform: translate3d(-2px, 1px, 0); }
}

.atmosphere {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}

.fixed-glow {
  position: absolute;
  width: 420px;
  height: 420px;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.18;
  transform: translateY(calc(var(--scroll-depth, 0px) * -0.05));
}

.glow-cyan {
  top: 12vh;
  left: -140px;
  background: var(--electric-cyan);
}

.glow-magenta {
  right: -130px;
  top: 46vh;
  background: var(--hot-magenta);
}

.global-stream {
  position: absolute;
  left: 0;
  width: 100vw;
  overflow: hidden;
  color: rgba(0, 229, 255, 0.2);
  font-family: "IBM Plex Sans", monospace;
  font-size: 11px;
  font-weight: 300;
  letter-spacing: 0.18em;
  white-space: nowrap;
}

.global-stream span {
  display: inline-block;
  min-width: 220vw;
  animation: telemetry 60s linear infinite;
}

.stream-a { top: 16vh; opacity: 0.75; }
.stream-b { top: 52vh; opacity: 0.55; }
.stream-c { top: 83vh; opacity: 0.65; }
.stream-b span { animation-duration: 72s; animation-direction: reverse; }
.stream-c span { animation-duration: 84s; }

@keyframes telemetry {
  from { transform: translateX(-25%); }
  to { transform: translateX(25%); }
}

.nav-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(20px, 4vw, 54px);
  background: rgba(10, 10, 18, 0.78);
  border-bottom: 1px solid rgba(0, 229, 255, 0.15);
  backdrop-filter: blur(12px);
}

.nav-logo {
  color: var(--electric-cyan);
  font-family: "Audiowide", sans-serif;
  font-size: 0.84rem;
  letter-spacing: 0.16em;
}

.nav-link {
  border: 0;
  background: transparent;
  color: var(--pale-lavender);
  cursor: pointer;
  font-family: "Rajdhani", sans-serif;
  font-size: 0.95rem;
  letter-spacing: 0.04em;
  transition: color 200ms ease, text-shadow 200ms ease;
}

.nav-link:hover {
  color: var(--electric-cyan);
  text-shadow: 2px 0 var(--hot-magenta), -2px 0 var(--electric-cyan);
}

.vault-section {
  position: relative;
  z-index: 3;
  min-height: 100vh;
  overflow: hidden;
}

.letterbox {
  position: absolute;
  left: 0;
  right: 0;
  z-index: 15;
  height: 48px;
  background: var(--void-black);
  box-shadow: 0 0 28px rgba(10, 10, 18, 0.95);
}

.letterbox.top { top: 0; }
.letterbox.bottom { bottom: 0; }

.scene {
  position: relative;
  z-index: 4;
  width: min(100%, 1500px);
  min-height: 100vh;
  margin: 0 auto;
  padding: 96px clamp(22px, 4vw, 64px);
  display: flex;
  align-items: center;
}

.scene-centered {
  justify-content: center;
  text-align: center;
}

.asymmetric {
  justify-content: space-between;
  gap: 5vw;
}

.left-heavy .content-panel { width: min(60vw, 820px); }
.left-heavy .visual-zone { width: 35%; }
.right-heavy .content-panel { width: min(58vw, 760px); order: 2; }
.right-heavy .visual-zone { width: 35%; order: 1; }

.section-perimeter {
  background: linear-gradient(180deg, rgba(10, 10, 18, 0.72) 0%, rgba(18, 18, 42, 0.92) 100%);
}

.section-mechanism {
  background: linear-gradient(180deg, rgba(18, 18, 42, 0.72) 0%, rgba(10, 10, 18, 0.92) 100%);
}

.section-sanctum {
  background:
    radial-gradient(circle at 54% 50%, rgba(255, 179, 71, 0.18), transparent 36vw),
    radial-gradient(circle at 20% 54%, rgba(0, 229, 255, 0.16), transparent 34vw),
    radial-gradient(circle at 86% 42%, rgba(255, 45, 123, 0.16), transparent 34vw),
    linear-gradient(180deg, rgba(10, 10, 18, 0.88), rgba(18, 18, 42, 0.88));
}

.section-seal {
  background: radial-gradient(circle at 50% 46%, rgba(255, 179, 71, 0.14), transparent 30vw), linear-gradient(180deg, var(--deep-indigo), var(--void-black));
}

.approach-copy {
  position: relative;
  z-index: 4;
}

.hero-title {
  display: flex;
  justify-content: center;
  gap: 0.08em;
  color: var(--electric-cyan);
  font-family: "Audiowide", sans-serif;
  font-size: clamp(2.2rem, 8vw, 7.5rem);
  font-weight: 400;
  letter-spacing: 0.08em;
  line-height: 1.15;
  text-transform: uppercase;
  text-shadow: 0 0 18px rgba(0, 229, 255, 0.24);
}

.hero-title span {
  display: inline-block;
  opacity: 0;
  transform: translateY(70px);
}

.hero-title.visible span {
  animation: letterReveal 520ms var(--reveal-curve) forwards;
}

.hero-title.visible span:nth-child(1) { animation-delay: 0ms; }
.hero-title.visible span:nth-child(2) { animation-delay: 80ms; }
.hero-title.visible span:nth-child(3) { animation-delay: 160ms; }
.hero-title.visible span:nth-child(4) { animation-delay: 240ms; }
.hero-title.visible span:nth-child(5) { animation-delay: 320ms; }
.hero-title.visible span:nth-child(6) { animation-delay: 400ms; }
.hero-title.visible span:nth-child(7) { animation-delay: 480ms; }
.hero-title.visible span:nth-child(8) { animation-delay: 560ms; }
.hero-title.visible span:nth-child(9) { animation-delay: 640ms; }

@keyframes letterReveal {
  to { opacity: 1; transform: translateY(0); }
}

.tagline, .eyebrow, .seal-word {
  font-family: "Rajdhani", sans-serif;
  letter-spacing: 0.04em;
}

.tagline {
  margin-top: 1rem;
  color: var(--pale-lavender);
  font-size: clamp(1.1rem, 2vw, 1.8rem);
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 500ms ease 880ms, transform 500ms ease 880ms;
}

.section-approach.visible .tagline { opacity: 1; transform: translateY(0); }

.hero-glow {
  position: absolute;
  width: 420px;
  height: 420px;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.1;
  animation: glowPulse 4s ease-in-out infinite;
}

.hero-cyan { left: 8%; top: 18%; background: var(--electric-cyan); }
.hero-magenta { right: 6%; bottom: 18%; background: var(--hot-magenta); animation-delay: 2s; }

@keyframes glowPulse {
  0%, 100% { opacity: 0.1; transform: scale(0.94); }
  50% { opacity: 0.25; transform: scale(1.08); }
}

.content-panel {
  position: relative;
  padding: clamp(28px, 4vw, 54px);
  background: var(--charcoal-glass);
  border: 1px solid rgba(0, 229, 255, 0.15);
  border-radius: 18px;
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.42), inset 0 1px 0 rgba(224, 214, 255, 0.08);
  backdrop-filter: blur(12px);
  opacity: 0;
  transition: opacity 600ms var(--reveal-curve), transform 600ms var(--reveal-curve), border-color 200ms ease, box-shadow 200ms ease;
}

.content-panel:hover {
  border-color: rgba(0, 229, 255, 0.34);
  box-shadow: 0 26px 80px rgba(0, 0, 0, 0.5), 0 0 32px rgba(0, 229, 255, 0.08), inset 0 1px 0 rgba(224, 214, 255, 0.1);
}

.slide-left { transform: translateX(-22vw); }
.slide-right { transform: translateX(22vw); }
.content-panel.visible { opacity: 1; transform: translateX(0); }

.eyebrow {
  margin-bottom: 0.85rem;
  color: var(--pale-lavender);
  font-size: clamp(1rem, 1.7vw, 1.35rem);
  font-weight: 600;
  text-transform: uppercase;
}

.eyebrow.amber { color: var(--amber-warm); }

h2 {
  margin-bottom: 1.2rem;
  color: var(--electric-cyan);
  font-family: "Audiowide", sans-serif;
  font-size: clamp(1.6rem, 3.5vw, 3rem);
  font-weight: 400;
  letter-spacing: 0.08em;
  line-height: 1.15;
  text-transform: uppercase;
}

.sanctum-panel h2, .seal-title { color: var(--amber-warm); }

p {
  color: var(--cool-silver);
  font-size: clamp(0.95rem, 1.2vw, 1.15rem);
  font-weight: 300;
  line-height: 1.75;
}

p + p { margin-top: 1rem; }

.cyan, .amber {
  transition: text-shadow 200ms ease, color 200ms ease;
}

.cyan { color: var(--electric-cyan); font-weight: 400; }
.amber { color: var(--amber-warm); font-weight: 400; }
.cyan:hover { text-shadow: 2px 0 var(--hot-magenta), -2px 0 var(--electric-cyan); }
.amber:hover { text-shadow: 2px 0 var(--electric-cyan), -2px 0 var(--hot-magenta); }

.visual-zone {
  position: relative;
  min-height: 420px;
  display: grid;
  place-items: center;
}

.shield-core {
  position: relative;
  width: min(34vw, 390px);
  height: min(34vw, 390px);
  min-width: 240px;
  min-height: 240px;
  display: grid;
  place-items: center;
}

.shield-core::before {
  content: "";
  position: absolute;
  inset: 42%;
  border-radius: 50%;
  background: var(--amber-warm);
  box-shadow: 0 0 28px rgba(255, 179, 71, 0.72);
}

.shield-ring {
  position: absolute;
  inset: 50%;
  border: 1px solid var(--electric-cyan);
  border-radius: 50%;
  opacity: 0;
  transform: translate(-50%, -50%) scale(0.2);
}

.shield-core.visible .shield-ring { animation: shieldPulse 2.4s ease-out infinite; }
.ring-1 { width: 18%; height: 18%; border-color: var(--hot-magenta); animation-delay: 0ms; }
.ring-2 { width: 34%; height: 34%; border-color: var(--pale-lavender); animation-delay: 200ms; }
.ring-3 { width: 52%; height: 52%; border-color: var(--electric-cyan); animation-delay: 400ms; }
.ring-4 { width: 72%; height: 72%; border-color: var(--pale-lavender); animation-delay: 600ms; }
.ring-5 { width: 94%; height: 94%; border-color: var(--electric-cyan); animation-delay: 800ms; }

@keyframes shieldPulse {
  0% { opacity: 0; transform: translate(-50%, -50%) scale(0.82); }
  18% { opacity: 0.92; }
  100% { opacity: 0; transform: translate(-50%, -50%) scale(1.18); }
}

.shield-label {
  position: absolute;
  bottom: 7%;
  color: rgba(224, 214, 255, 0.72);
  font-family: "Rajdhani", sans-serif;
  font-size: 0.78rem;
  letter-spacing: 0.18em;
}

.flow-zone {
  align-content: center;
  gap: 22px;
  overflow: hidden;
  border-left: 1px solid rgba(0, 229, 255, 0.14);
  border-right: 1px solid rgba(255, 45, 123, 0.12);
}

.data-flow {
  width: 100%;
  overflow: hidden;
  color: rgba(0, 229, 255, 0.34);
  font-family: "IBM Plex Sans", monospace;
  font-size: 11px;
  font-weight: 300;
  letter-spacing: 0.16em;
  white-space: nowrap;
}

.data-flow span {
  display: inline-block;
  min-width: 190%;
  animation: flowMove 8s linear infinite;
}

.flow-2 span { animation-duration: 12s; color: var(--pale-lavender); opacity: 0.45; }
.flow-3 span { animation-duration: 18s; color: var(--hot-magenta); opacity: 0.34; }

@keyframes flowMove {
  from { transform: translateX(74%); }
  to { transform: translateX(-100%); }
}

.flow-glass {
  position: absolute;
  inset: 15% 8%;
  border: 1px solid rgba(224, 214, 255, 0.1);
  background: linear-gradient(115deg, transparent, rgba(224, 214, 255, 0.06), transparent);
  border-radius: 20px;
  backdrop-filter: blur(2px);
}

.panel-lock, .seal-lock {
  border: 2px solid var(--amber-warm);
  border-radius: 5px;
  box-shadow: 0 0 12px rgba(255, 179, 71, 0.18);
}

.panel-lock {
  position: absolute;
  right: 24px;
  top: 24px;
  width: 24px;
  height: 20px;
  opacity: 0.78;
}

.panel-lock::before, .seal-lock::before {
  content: "";
  position: absolute;
  left: 50%;
  border: inherit;
  border-bottom: 0;
  border-radius: 999px 999px 0 0;
  transform-origin: 0 100%;
}

.panel-lock::before {
  top: -15px;
  width: 13px;
  height: 15px;
  transform: translateX(-50%) rotate(30deg);
}

.content-panel.visible .panel-lock::before { animation: shackleClose 400ms var(--spring-curve) 360ms forwards; }

@keyframes shackleClose {
  to { transform: translateX(-50%) rotate(0deg); }
}

.sanctum-scene { justify-content: center; }
.sanctum-panel { width: min(75vw, 1080px); margin-left: -5%; }
.sanctum-text { font-family: "Rajdhani", sans-serif; font-size: clamp(1.1rem, 1.7vw, 1.55rem); color: var(--pale-lavender); }

.seal-wrap {
  display: grid;
  justify-items: center;
  gap: 28px;
}

.seal-title {
  font-family: "Audiowide", sans-serif;
  font-size: clamp(2rem, 4vw, 4.4rem);
  font-weight: 400;
  letter-spacing: 0.08em;
  line-height: 1.15;
  text-transform: uppercase;
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 600ms var(--reveal-curve), transform 600ms var(--reveal-curve);
}

.section-seal.visible .seal-title { opacity: 1; transform: translateY(0); }

.seal-lock {
  position: relative;
  width: 64px;
  height: 54px;
  border-width: 3px;
  opacity: 0;
  transform: scale(0.68);
}

.seal-lock::before {
  top: -36px;
  width: 34px;
  height: 36px;
  border-width: 3px;
  transform: translateX(-50%) rotate(30deg);
}

.section-seal.visible .seal-lock {
  animation: sealAppear 500ms var(--spring-curve) 300ms forwards;
}

.section-seal.visible .seal-lock::before {
  animation: sealClose 600ms var(--spring-curve) 650ms forwards;
}

@keyframes sealAppear {
  to { opacity: 1; transform: scale(1); box-shadow: 0 0 32px rgba(255, 179, 71, 0.28); }
}

@keyframes sealClose {
  to { transform: translateX(-50%) rotate(0deg); }
}

.seal-word {
  color: var(--pale-lavender);
  font-size: clamp(1.2rem, 2.5vw, 2rem);
  opacity: 0;
  transform: translateY(12px);
}

.section-seal.visible .seal-word {
  animation: enclosedFade 600ms ease 1250ms forwards;
}

@keyframes enclosedFade {
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 820px) {
  .scene { padding: 82px 20px; }
  .asymmetric { flex-direction: column; justify-content: center; gap: 34px; }
  .left-heavy .content-panel, .right-heavy .content-panel, .left-heavy .visual-zone, .right-heavy .visual-zone, .sanctum-panel { width: 100%; margin-left: 0; order: initial; }
  .visual-zone { min-height: 280px; }
  .letterbox { height: 36px; }
  .hero-title { font-size: clamp(2rem, 11vw, 4rem); gap: 0.02em; }
  .nav-bar { padding: 0 18px; }
  .nav-link { font-size: 0.82rem; }
}