:root {
  color-scheme: dark;
  --black: #050505;
  --white: #f4f4f2;
  --soft: #9a9a96;
  --dim: #6f6f6b;
  --line: rgb(244 244 242 / 16%);
  --serif: "Bodoni Moda", Didot, "Bodoni 72", Georgia, serif;
  --mono: "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;
  background: var(--black);
  font-family: var(--mono);
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

html {
  background: var(--black);
  scroll-behavior: smooth;
}

body {
  margin: 0;
  overflow-x: hidden;
  background: var(--black);
  color: var(--white);
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
}

a:hover {
  color: var(--soft);
}

::selection {
  background: var(--white);
  color: var(--black);
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 0.75rem;
  left: 0.75rem;
  padding: 0.75rem 1rem;
  transform: translateY(-160%);
  background: var(--white);
  color: var(--black);
  font-size: 0.875rem;
}

.skip-link:focus {
  transform: translateY(0);
}

.progress {
  position: fixed;
  z-index: 60;
  inset: 0 0 auto;
  height: 1px;
  background: rgb(244 244 242 / 12%);
}

.progress span {
  display: block;
  width: 0;
  height: 100%;
  background: var(--white);
}

.vignette {
  position: fixed;
  z-index: 55;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(120% 90% at 50% 45%, transparent 40%, rgb(0 0 0 / 58%) 100%);
}

.site-header {
  position: fixed;
  z-index: 58;
  inset: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.375rem clamp(1.125rem, 4vw, 3rem);
  color: #8f8f8b;
  font-size: 0.75rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  mix-blend-mode: difference;
}

.hero-track {
  position: relative;
  height: 340vh;
}

.hero-stage {
  position: sticky;
  top: 0;
  display: grid;
  height: 100vh;
  height: 100svh;
  place-items: center;
  overflow: hidden;
}

.black-hole {
  position: absolute;
  width: min(54vmin, 30rem);
  aspect-ratio: 1;
  will-change: transform;
}

.accretion-disc {
  position: absolute;
  inset: -20%;
  border-radius: 50%;
  background: conic-gradient(
    from 0deg,
    transparent 0%,
    rgb(255 255 255 / 90%) 14%,
    transparent 30%,
    rgb(255 255 255 / 28%) 48%,
    transparent 62%,
    rgb(255 255 255 / 72%) 84%,
    transparent 100%
  );
  filter: blur(1rem);
  mask: radial-gradient(circle, transparent 43%, #000 51%, #000 74%, transparent 92%);
  animation: orbit 38s linear infinite;
}

.event-horizon {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  background: #000;
  box-shadow:
    0 0 0 1.5px rgb(244 244 242 / 85%),
    0 0 7.5rem 1.125rem rgb(255 255 255 / 16%),
    inset 0 0 3.75rem 0.625rem #000;
}

.hero-copy {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: clamp(1rem, 3vh, 2.125rem);
  padding: 0 1.25rem;
  text-align: center;
  mix-blend-mode: exclusion;
  will-change: opacity;
}

.hero-copy h1 {
  display: flex;
  justify-content: center;
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(3.6rem, 17vw, 14.5rem);
  font-weight: 400;
  letter-spacing: 0.04em;
  line-height: 0.9;
}

.hero-copy h1 span {
  display: inline-block;
  will-change: transform, filter;
}

.hero-copy p {
  margin: 0;
  font-size: clamp(0.75rem, 1.6vw, 0.875rem);
  letter-spacing: 0.4em;
  text-transform: uppercase;
}

.descent {
  position: absolute;
  z-index: 3;
  bottom: max(2.125rem, env(safe-area-inset-bottom));
  left: 50%;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.625rem;
  transform: translateX(-50%);
  color: #8f8f8b;
  font-size: 0.75rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  animation: hint 2.6s ease-in-out infinite;
}

.descent span:last-child {
  font-size: 1rem;
}

.year-marker {
  position: relative;
  display: grid;
  min-height: 100vh;
  min-height: 100svh;
  padding: clamp(5.625rem, 18vh, 12.5rem) clamp(1.25rem, 6vw, 5rem);
  place-items: center;
}

.year-inner {
  position: relative;
  display: flex;
  width: min(100%, 75rem);
  align-items: center;
  justify-content: center;
}

.year {
  font-family: var(--serif);
  font-size: clamp(6rem, 27vw, 22rem);
  font-weight: 400;
  letter-spacing: -0.055em;
  line-height: 0.72;
}

.axis {
  position: absolute;
  right: 0;
  bottom: -2.5rem;
  color: var(--dim);
  font-size: 0.75rem;
  letter-spacing: 0.28em;
}

.number {
  color: #8f8f8b;
  font-size: 0.75rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
}

.principles {
  position: relative;
  padding: clamp(3.75rem, 10vh, 7.5rem) clamp(1.25rem, 6vw, 5rem) clamp(5.625rem, 16vh, 11.25rem);
}

.principles-grid {
  display: grid;
  max-width: 75rem;
  margin: 0 auto;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(1.75rem, 4vw, 4rem);
}

.principle {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  padding-top: 1.375rem;
  border-top: 1px solid var(--line);
}

.principle h2 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(1.5rem, 2.4vw, 2rem);
  font-weight: 400;
}

.collapse-track {
  position: relative;
  height: 240vh;
}

.collapse-stage {
  position: sticky;
  top: 0;
  display: grid;
  height: 100vh;
  height: 100svh;
  place-items: center;
  overflow: hidden;
}

.halo {
  position: absolute;
  width: min(34vmin, 18.75rem);
  aspect-ratio: 1;
  border-radius: 50%;
  background: #000;
  box-shadow:
    0 0 0 1px rgb(244 244 242 / 50%),
    0 0 5.625rem 0.875rem rgb(255 255 255 / 12%);
}

.collapse-stage h2 {
  position: relative;
  z-index: 2;
  margin: 0;
  padding: 0 1.25rem;
  font-family: var(--serif);
  font-size: clamp(2rem, 6.6vw, 6.5rem);
  font-weight: 400;
  letter-spacing: 0.5em;
  line-height: 1.02;
  text-align: center;
  text-wrap: balance;
  mix-blend-mode: exclusion;
  will-change: letter-spacing;
}

.marquee {
  position: absolute;
  bottom: 8%;
  left: 0;
  display: flex;
  width: max-content;
  color: var(--dim);
  font-size: clamp(0.75rem, 1.4vw, 0.875rem);
  letter-spacing: 0.38em;
  text-transform: uppercase;
  white-space: nowrap;
  will-change: transform;
}

footer {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.125rem;
  padding: clamp(2.5rem, 7vh, 4.375rem) clamp(1.25rem, 6vw, 5rem);
  border-top: 1px solid var(--line);
  color: var(--dim);
  font-size: 0.75rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
}

.reveal {
  opacity: 0;
  filter: blur(0.375rem);
  transform: translateY(1.625rem);
  transition:
    opacity 1s cubic-bezier(0.2, 0.7, 0.2, 1),
    transform 1.1s cubic-bezier(0.2, 0.7, 0.2, 1),
    filter 1s ease;
}

.reveal.is-visible {
  opacity: 1;
  filter: none;
  transform: none;
}

@keyframes orbit {
  to { transform: rotate(360deg); }
}

@keyframes hint {
  0%, 100% { opacity: 0.5; transform: translate(-50%, 0); }
  50% { opacity: 1; transform: translate(-50%, 0.4375rem); }
}

@media (max-width: 48rem) {
  .principles-grid {
    grid-template-columns: 1fr;
  }

  .principle {
    max-width: 34rem;
  }

  footer {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 30rem) {
  .site-header {
    font-size: 0.6875rem;
    letter-spacing: 0.16em;
  }

  .hero-copy h1 {
    font-size: clamp(3.25rem, 18vw, 5.25rem);
  }

  .hero-copy p {
    letter-spacing: 0.28em;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.001ms !important;
  }

  .hero-track,
  .collapse-track {
    height: 100vh;
    height: 100svh;
  }

  .reveal {
    opacity: 1;
    filter: none;
    transform: none;
  }
}