/* Multiverse — visual concept stylesheet.
   Static, same-origin only: self-hosted fonts, no external requests. */

/* ---------- Self-hosted type (SIL Open Font License, see assets/fonts/) ---------- */

@font-face {
  font-family: "Fraunces";
  font-style: normal;
  font-weight: 300 900;
  font-display: swap;
  src: url("../fonts/fraunces-variable-latin.woff2") format("woff2");
}

@font-face {
  font-family: "IBM Plex Sans";
  font-style: normal;
  font-weight: 400 600;
  font-display: swap;
  src: url("../fonts/ibm-plex-sans-variable-latin.woff2") format("woff2");
}

@font-face {
  font-family: "IBM Plex Mono";
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url("../fonts/ibm-plex-mono-400-latin.woff2") format("woff2");
}

@font-face {
  font-family: "IBM Plex Mono";
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url("../fonts/ibm-plex-mono-500-latin.woff2") format("woff2");
}

/* ---------- Tokens ---------- */

:root {
  --ink-900: #04060c;
  --ink-850: #070b14;
  --ink-800: #0b111d;
  --ink-700: #121a2a;
  --ink-600: #1b2536;

  --bone: #ede7db;
  --bone-dim: #b8b2a6;
  --slate: #909aae;
  --line: rgba(237, 231, 219, 0.13);
  --line-strong: rgba(237, 231, 219, 0.26);

  /* OpenScienceUniverse: warm amber, like a lamp-lit plate. */
  --science: #f2a63b;
  --science-soft: rgba(242, 166, 59, 0.14);
  --science-deep: #9a631a;
  --science-gate: #171005;

  /* CodeUniverse: cool jade, like phosphor on glass. */
  --code: #58caa6;
  --code-soft: rgba(88, 202, 166, 0.13);
  --code-deep: #1d7c60;
  --code-gate: #04140f;

  /* The crossing is neutral until a universe is chosen. */
  --accent: var(--bone);
  --accent-soft: rgba(237, 231, 219, 0.1);
  --accent-deep: #6d7488;
  --gate: #0a0e18;

  --display: "Fraunces", "Iowan Old Style", Georgia, serif;
  --sans: "IBM Plex Sans", "Avenir Next", "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", monospace;

  --shell: 1280px;
  --gutter: clamp(1.15rem, 4.5vw, 3.75rem);
  --measure: 64ch;
  --radius: 3px;

  --ease-out: cubic-bezier(0.16, 0.84, 0.28, 1);
  --ease-travel: cubic-bezier(0.7, 0, 0.18, 1);
}

body[data-universe="science"] {
  --accent: var(--science);
  --accent-soft: var(--science-soft);
  --accent-deep: var(--science-deep);
  --gate: var(--science-gate);
}

body[data-universe="code"] {
  --accent: var(--code);
  --accent-soft: var(--code-soft);
  --accent-deep: var(--code-deep);
  --gate: var(--code-gate);
}

/* ---------- Base ---------- */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background-color: var(--ink-900);
  color: var(--bone);
  font-family: var(--sans);
  font-size: clamp(0.98rem, 0.94rem + 0.2vw, 1.06rem);
  line-height: 1.68;
  font-synthesis-weight: none;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* Layered atmosphere: two horizon glows in the universe hues, plus grain. */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
  background:
    radial-gradient(58rem 40rem at 12% -8%, rgba(242, 166, 59, 0.13), transparent 62%),
    radial-gradient(52rem 38rem at 92% 4%, rgba(88, 202, 166, 0.11), transparent 60%),
    radial-gradient(90rem 60rem at 50% 120%, rgba(24, 34, 54, 0.75), transparent 70%),
    linear-gradient(178deg, var(--ink-850) 0%, var(--ink-900) 46%, #03050a 100%);
}

body[data-universe="science"]::before {
  background:
    radial-gradient(60rem 44rem at 8% -12%, rgba(242, 166, 59, 0.2), transparent 60%),
    radial-gradient(46rem 34rem at 96% 30%, rgba(88, 202, 166, 0.05), transparent 62%),
    radial-gradient(90rem 60rem at 50% 120%, rgba(38, 27, 12, 0.6), transparent 70%),
    linear-gradient(178deg, #0a0803 0%, var(--ink-900) 52%, #04050a 100%);
}

body[data-universe="code"]::before {
  background:
    radial-gradient(60rem 44rem at 92% -12%, rgba(88, 202, 166, 0.17), transparent 60%),
    radial-gradient(46rem 34rem at 4% 28%, rgba(242, 166, 59, 0.05), transparent 62%),
    radial-gradient(90rem 60rem at 50% 120%, rgba(10, 34, 28, 0.6), transparent 70%),
    linear-gradient(178deg, #04100c 0%, var(--ink-900) 52%, #04050a 100%);
}

/* Fine grain, drawn once as an inline SVG turbulence field. */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: 0.4;
  mix-blend-mode: soft-light;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3'/%3E%3C/filter%3E%3Crect width='180' height='180' filter='url(%23n)' opacity='0.5'/%3E%3C/svg%3E");
}

img,
svg,
canvas {
  display: block;
  max-width: 100%;
}

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

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 2px;
}

::selection {
  background: var(--accent);
  color: var(--ink-900);
}

.sprite {
  position: absolute;
  width: 0;
  height: 0;
  overflow: hidden;
}

.skip-link {
  position: absolute;
  left: var(--gutter);
  top: -100px;
  z-index: 120;
  padding: 0.7rem 1.1rem;
  background: var(--bone);
  color: var(--ink-900);
  font-family: var(--mono);
  font-size: 0.76rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  transition: top 220ms var(--ease-out);
}

.skip-link:focus-visible {
  top: 1rem;
  outline-color: var(--bone);
}

/* ---------- Type ---------- */

h1,
h2,
h3 {
  margin: 0;
  font-family: var(--display);
  font-weight: 380;
  line-height: 1.02;
  letter-spacing: -0.015em;
  text-wrap: balance;
}

.display-xl {
  font-size: clamp(2.85rem, 8.4vw, 6.6rem);
  font-variation-settings: "opsz" 132, "wght" 330;
}

.display-l {
  font-size: clamp(2.35rem, 6.2vw, 4.6rem);
  font-variation-settings: "opsz" 96, "wght" 350;
}

.display-m {
  font-size: clamp(1.6rem, 1.2rem + 1.5vw, 2.5rem);
  font-variation-settings: "opsz" 40, "wght" 420;
  letter-spacing: -0.01em;
  line-height: 1.1;
}

.display-s {
  font-size: clamp(1.12rem, 1rem + 0.5vw, 1.4rem);
  font-variation-settings: "opsz" 20, "wght" 520;
  line-height: 1.2;
}

p {
  margin: 0 0 1.05em;
  text-wrap: pretty;
}

.lede {
  max-width: var(--measure);
  color: var(--bone-dim);
  font-size: clamp(1.04rem, 0.98rem + 0.5vw, 1.32rem);
  line-height: 1.6;
}

.muted {
  color: var(--slate);
}

code {
  font-family: var(--mono);
  font-size: 0.87em;
  letter-spacing: 0.02em;
  color: var(--bone);
  background: rgba(237, 231, 219, 0.06);
  padding: 0.12em 0.4em;
  border-radius: 2px;
}

.label {
  font-family: var(--mono);
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--slate);
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  margin: 0 0 1.4rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--accent);
}

.eyebrow::before {
  content: "";
  width: clamp(1.6rem, 5vw, 3.4rem);
  height: 1px;
  background: currentColor;
  opacity: 0.7;
}

.seam {
  height: 2px;
  width: clamp(7rem, 18vw, 12rem);
  border: 0;
  margin: 1.9rem 0 0;
  background: linear-gradient(90deg, var(--science), var(--code));
  opacity: 0.85;
}

.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* ---------- Masthead ---------- */

.masthead {
  position: sticky;
  top: 0;
  z-index: 60;
  background: linear-gradient(180deg, rgba(4, 6, 12, 0.94) 0%, rgba(4, 6, 12, 0.76) 62%, transparent 100%);
  backdrop-filter: blur(9px);
}

.masthead-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.8rem 1.6rem;
  padding-block: 1rem;
  border-bottom: 1px solid var(--line);
}

.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 0.62rem;
  font-family: var(--mono);
  font-size: 0.84rem;
  font-weight: 500;
  letter-spacing: 0.34em;
  text-transform: uppercase;
  color: var(--bone);
}

.wordmark svg {
  width: 26px;
  height: 26px;
  color: var(--accent);
  flex: none;
}

.wordmark:hover svg,
.wordmark:focus-visible svg {
  transform: rotate(-14deg);
}

.wordmark svg {
  transition: transform 460ms var(--ease-out);
}

.nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem;
  margin-left: auto;
}

.nav a,
.nav button {
  position: relative;
  padding: 0.42rem 0.72rem;
  font-family: var(--mono);
  font-size: 0.735rem;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--bone-dim);
  background: none;
  border: 1px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  transition: color 200ms var(--ease-out), border-color 200ms var(--ease-out), background-color 200ms var(--ease-out);
}

.nav a:hover,
.nav button:hover {
  color: var(--bone);
  border-color: var(--line-strong);
}

.nav a[aria-current="page"] {
  color: var(--accent);
  border-color: color-mix(in oklab, var(--accent) 38%, transparent);
  background: var(--accent-soft);
}

.nav .nav-science:hover {
  color: var(--science);
  border-color: color-mix(in oklab, var(--science) 40%, transparent);
}

.nav .nav-code:hover {
  color: var(--code);
  border-color: color-mix(in oklab, var(--code) 40%, transparent);
}

.status-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.3rem 0.7rem 0.3rem 0.55rem;
  border: 1px dashed var(--line-strong);
  border-radius: 999px;
  font-family: var(--mono);
  font-size: 0.66rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--slate);
  white-space: nowrap;
}

.status-chip::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

/* ---------- Sky field (decorative) ---------- */

.skyfield {
  position: fixed;
  inset: 0;
  z-index: -1;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.artwork-note {
  margin: 0;
  font-family: var(--mono);
  font-size: 0.66rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--slate);
  opacity: 0.82;
}

/* ---------- Hero ---------- */

.hero {
  position: relative;
  padding-block: clamp(3rem, 9vh, 6.5rem) clamp(2.4rem, 6vh, 4rem);
}

.hero-title .line {
  display: block;
}

.hero-title .line-2 {
  color: var(--bone);
  font-variation-settings: "opsz" 132, "wght" 300;
}

.hero-body {
  display: grid;
  gap: clamp(1.6rem, 4vw, 3.4rem);
  align-items: end;
  margin-top: clamp(1.6rem, 4vh, 2.6rem);
}

/* ---------- Diptych portals ---------- */

.diptych {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  margin-top: clamp(2.2rem, 6vh, 3.6rem);
}

.portal {
  position: relative;
  flex: 1 1 0;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  min-height: 15rem;
  padding: clamp(1.3rem, 2.4vw, 2.1rem);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.028), transparent 42%),
    rgba(7, 11, 20, 0.62);
  overflow: hidden;
  isolation: isolate;
  transition: flex-grow 620ms var(--ease-out), border-color 320ms var(--ease-out),
    background-color 320ms var(--ease-out), transform 420ms var(--ease-out);
}

.portal::before {
  /* universe texture: spectral arcs for science, lattice for code */
  content: "";
  position: absolute;
  inset: -20% -10%;
  z-index: -1;
  opacity: 0.5;
  transition: opacity 420ms var(--ease-out), transform 900ms var(--ease-out);
}

.portal-science::before {
  background:
    repeating-radial-gradient(circle at 88% 8%,
      color-mix(in oklab, var(--science) 26%, transparent) 0 1px,
      transparent 1px 22px);
  transform: scale(1.02);
}

.portal-code::before {
  background:
    repeating-linear-gradient(0deg, color-mix(in oklab, var(--code) 18%, transparent) 0 1px, transparent 1px 26px),
    repeating-linear-gradient(90deg, color-mix(in oklab, var(--code) 18%, transparent) 0 1px, transparent 1px 26px);
  mask-image: radial-gradient(70% 70% at 12% 92%, #000 0%, transparent 78%);
}

.portal::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: radial-gradient(38rem 22rem at var(--glow-x, 50%) var(--glow-y, 120%), var(--accent-soft), transparent 70%);
  opacity: 0;
  transition: opacity 420ms var(--ease-out);
}

.portal:hover,
.portal:focus-visible {
  flex-grow: 1.42;
  border-color: color-mix(in oklab, var(--portal-hue) 46%, var(--line));
  background-color: rgba(9, 14, 24, 0.82);
}

.portal:hover::before,
.portal:focus-visible::before {
  opacity: 0.92;
}

.portal:hover::after,
.portal:focus-visible::after {
  opacity: 1;
}

.portal-science {
  --portal-hue: var(--science);
  --accent: var(--science);
  --accent-soft: var(--science-soft);
  --accent-deep: var(--science-deep);
}

.portal-code {
  --portal-hue: var(--code);
  --accent: var(--code);
  --accent-soft: var(--code-soft);
  --accent-deep: var(--code-deep);
}

.portal-index {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.22em;
  color: var(--portal-hue);
}

.portal-name {
  font-family: var(--display);
  font-size: clamp(1.7rem, 1.3rem + 1.9vw, 3.05rem);
  font-variation-settings: "opsz" 72, "wght" 380;
  line-height: 1;
  letter-spacing: -0.02em;
  margin: 0;
  color: var(--bone);
}

.portal-charter {
  margin: 0;
  max-width: 40ch;
  color: var(--bone-dim);
  font-size: 0.98rem;
}

.portal-foot {
  margin-top: auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem 1.4rem;
  padding-top: 1.1rem;
  border-top: 1px solid var(--line);
}

.portal-enter {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-family: var(--mono);
  font-size: 0.74rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--portal-hue);
}

.portal-enter svg {
  width: 20px;
  height: 20px;
  transition: transform 380ms var(--ease-out);
}

.portal:hover .portal-enter svg,
.portal:focus-visible .portal-enter svg {
  transform: translateX(6px);
}

.portal-status {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--mono);
  font-size: 0.66rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--slate);
}

.portal-status svg {
  width: 15px;
  height: 15px;
  color: var(--portal-hue);
  opacity: 0.85;
}

/* ---------- Sections ---------- */

.band {
  padding-block: clamp(3rem, 8vh, 5.5rem);
  border-top: 1px solid var(--line);
}

.band-head {
  display: grid;
  gap: 1rem;
  max-width: var(--measure);
  margin-bottom: clamp(1.9rem, 4vh, 3rem);
}

/* ---------- Ledger ---------- */

.ledger {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.ledger-row {
  display: grid;
  grid-template-columns: 2.4rem minmax(0, 1fr);
  gap: 0.55rem 1rem;
  align-items: baseline;
  padding: 1.05rem 0.4rem;
  border-bottom: 1px solid var(--line);
  transition: background-color 260ms var(--ease-out), padding-left 260ms var(--ease-out);
}

.ledger-row:hover {
  background: rgba(255, 255, 255, 0.022);
  padding-left: 0.85rem;
}

.ledger-index {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  color: var(--slate);
}

.ledger-main {
  display: grid;
  gap: 0.3rem;
}

.ledger-name {
  font-family: var(--display);
  font-size: 1.16rem;
  font-variation-settings: "opsz" 24, "wght" 460;
  color: var(--bone);
}

.ledger-meta {
  grid-column: 2;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.55rem 1rem;
}

.ledger-status {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--mono);
  font-size: 0.66rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  white-space: nowrap;
}

.ledger-status svg {
  width: 15px;
  height: 15px;
  flex: none;
}

.ledger-where {
  font-family: var(--mono);
  font-size: 0.66rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--bone-dim);
  padding: 0.14rem 0.5rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  white-space: nowrap;
}

.ledger-where[data-hue="science"] {
  color: var(--science);
  border-color: color-mix(in oklab, var(--science) 34%, transparent);
}

.ledger-where[data-hue="code"] {
  color: var(--code);
  border-color: color-mix(in oklab, var(--code) 34%, transparent);
}

.ledger-note {
  color: var(--slate);
  font-size: 0.9rem;
  max-width: 52ch;
}

/* ---------- Sealed / pending state ---------- */

.sealed {
  position: relative;
  border: 1px dashed color-mix(in oklab, var(--accent) 42%, var(--line));
  border-radius: var(--radius);
  background-color: rgba(255, 255, 255, 0.015);
  background-image: repeating-linear-gradient(135deg,
      rgba(237, 231, 219, 0.055) 0 1px,
      transparent 1px 10px);
}

.sealed-body {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.85rem;
  padding: clamp(1.4rem, 3vw, 2.2rem);
  min-height: 11rem;
}

.seal {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--mono);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
}

.seal svg {
  width: 22px;
  height: 22px;
  flex: none;
}

.sealed-text {
  margin: 0;
  max-width: 46ch;
  color: var(--bone-dim);
  font-size: 0.94rem;
}

.sealed-legend {
  margin: 1.4rem 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 1.6rem;
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--slate);
}

.legend-key {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.legend-swatch {
  width: 26px;
  height: 14px;
  border: 1px dashed var(--line-strong);
  background-image: repeating-linear-gradient(135deg, rgba(237, 231, 219, 0.16) 0 1px, transparent 1px 5px);
}

/* ---------- Plates grid ---------- */

.plates {
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
}

.plate {
  margin: 0;
  display: flex;
  flex-direction: column;
}

.plate-head {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  padding: 0 0.15rem 0.85rem;
}

.plate-num {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--accent);
}

.plate-title {
  margin: 0;
  font-family: var(--display);
  font-size: 1.22rem;
  font-variation-settings: "opsz" 28, "wght" 460;
  letter-spacing: -0.005em;
  color: var(--bone);
}

.plate-def {
  margin: 0 0 1rem;
  padding: 0 0.15rem;
  color: var(--slate);
  font-size: 0.92rem;
  max-width: 48ch;
}

.plate .sealed-body {
  flex: 1;
  justify-content: center;
}

.panel-sealed {
  display: grid;
  gap: 1.1rem;
  justify-items: start;
  padding: clamp(1.5rem, 3.4vw, 2.6rem);
}

.panel-sealed .sealed-text {
  margin: 0;
}

/* ---------- Notes / prose blocks ---------- */

.notes {
  display: grid;
  gap: 1.6rem;
  grid-template-columns: 1fr;
}

.note {
  padding-top: 1.1rem;
  border-top: 1px solid var(--line);
}

.note h3 {
  margin-bottom: 0.55rem;
  color: var(--bone);
}

.note p {
  margin: 0;
  color: var(--bone-dim);
  font-size: 0.96rem;
  max-width: 46ch;
}

.rules {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.1rem;
  max-width: 74ch;
}

.rules li {
  position: relative;
  padding: 0.85rem 0 0.85rem 2rem;
  border-bottom: 1px solid var(--line);
  color: var(--bone-dim);
}

.rules li::before {
  content: "";
  position: absolute;
  left: 0.2rem;
  top: 1.45rem;
  width: 9px;
  height: 1px;
  background: var(--accent);
}

.panel {
  padding: clamp(1.5rem, 3.4vw, 2.6rem);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.026), transparent 55%), rgba(8, 12, 21, 0.6);
}

.panel + .panel {
  margin-top: 1rem;
}

/* ---------- Universe head ---------- */

.universe-head {
  padding-block: clamp(2.6rem, 7vh, 5rem) clamp(2rem, 5vh, 3.2rem);
}

.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin: 1.8rem 0 0;
  padding: 0;
  list-style: none;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 0.8rem;
  border: 1px dashed color-mix(in oklab, var(--accent) 40%, var(--line));
  border-radius: 999px;
  font-family: var(--mono);
  font-size: 0.66rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--bone-dim);
}

.chip::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

.return-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.8rem 1.4rem;
  padding-block: 0.9rem;
  border-bottom: 1px solid var(--line);
}

.return-bar-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.8rem 1.4rem;
}

.return-link {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.4rem 0.85rem 0.4rem 0.6rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-family: var(--mono);
  font-size: 0.71rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--bone);
  background: rgba(255, 255, 255, 0.02);
  transition: border-color 240ms var(--ease-out), background-color 240ms var(--ease-out), transform 240ms var(--ease-out);
}

.return-link svg {
  width: 19px;
  height: 19px;
  color: var(--accent);
  transition: transform 320ms var(--ease-out);
}

.return-link:hover,
.return-link:focus-visible {
  border-color: color-mix(in oklab, var(--accent) 48%, var(--line));
  background: var(--accent-soft);
  transform: translateX(-3px);
}

.return-link:hover svg,
.return-link:focus-visible svg {
  transform: translateX(-4px);
}

.return-note {
  margin: 0;
  font-family: var(--mono);
  font-size: 0.66rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--slate);
}

/* ---------- Footer ---------- */

.footer {
  margin-top: clamp(3rem, 8vh, 5rem);
  padding-block: clamp(2rem, 5vh, 3rem) clamp(2.4rem, 6vh, 3.4rem);
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, transparent, rgba(3, 5, 10, 0.7));
}

.footer-grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: 1fr;
}

.footer-routes {
  list-style: none;
  margin: 0.9rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.45rem;
}

.footer-routes a {
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--bone-dim);
  border-bottom: 1px solid transparent;
  transition: color 200ms var(--ease-out), border-color 200ms var(--ease-out);
}

.footer-routes a:hover,
.footer-routes a:focus-visible {
  color: var(--accent);
  border-color: currentColor;
}

.footer-note {
  margin: 0;
  max-width: 56ch;
  color: var(--slate);
  font-size: 0.88rem;
}

.colophon {
  margin-top: 2.4rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 2rem;
  font-family: var(--mono);
  font-size: 0.64rem;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--slate);
}

/* ---------- Aperture travel ---------- */

.aperture {
  position: fixed;
  z-index: 100;
  top: var(--travel-y, 50%);
  left: var(--travel-x, 50%);
  /* Radius 142.5vmax is at least sqrt(2) times the longest edge, so the disc covers
     every viewport aspect from any in-viewport travel point, square windows
     included; 130vmax left the far corner of near-square viewports uncovered. */
  width: 285vmax;
  height: 285vmax;
  margin: -142.5vmax 0 0 -142.5vmax;
  border-radius: 50%;
  pointer-events: none;
  display: none;
  opacity: 0;
  transform: scale(0);
  background: var(--gate);
  background: radial-gradient(circle closest-side at 50% 50%,
      var(--gate) 0 52%,
      color-mix(in oklab, var(--accent) 34%, var(--gate)) 74%,
      color-mix(in oklab, var(--accent) 78%, var(--gate)) 100%);
  will-change: transform, opacity;
}

/* The gate takes the colour of the universe being entered, so departure and
   arrival read as one continuous move. */
.aperture[data-hue="science"] {
  --accent: var(--science);
  --gate: var(--science-gate);
}

.aperture[data-hue="code"] {
  --accent: var(--code);
  --gate: var(--code-gate);
}

.aperture[data-hue="crossing"] {
  --accent: var(--bone);
  --gate: #080c15;
}

html.is-arriving .aperture {
  display: block;
  opacity: 1;
  transform: scale(1);
}

.aperture.is-closing {
  display: block;
  animation: aperture-close 460ms var(--ease-travel) forwards;
}

.aperture.is-opening {
  display: block;
  animation: aperture-open 620ms var(--ease-travel) forwards;
}

@keyframes aperture-close {
  from {
    opacity: 1;
    transform: scale(0);
  }

  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes aperture-open {
  from {
    opacity: 1;
    transform: scale(1);
  }

  to {
    opacity: 0;
    transform: scale(0);
  }
}

/* ---------- Load reveal ---------- */

@media (prefers-reduced-motion: no-preference) {
  .rise {
    animation: rise 820ms var(--ease-out) both;
    animation-delay: calc(var(--rise-i, 0) * 90ms + 60ms);
  }

  @keyframes rise {
    from {
      opacity: 0;
      transform: translateY(18px);
    }

    to {
      opacity: 1;
      transform: none;
    }
  }
}

/* Scroll reveal is only armed when scripting is available, so content is never hidden without it. */
html.js .reveal {
  opacity: 0;
  transform: translateY(20px);
}

html.js .reveal.is-in {
  opacity: 1;
  transform: none;
  transition: opacity 720ms var(--ease-out), transform 720ms var(--ease-out);
}

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

  html.js .reveal {
    opacity: 1;
    transform: none;
  }

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

  .aperture {
    display: none !important;
  }

  .portal:hover,
  .portal:focus-visible {
    flex-grow: 1;
  }
}

/* ---------- Responsive ---------- */

@media (min-width: 680px) {
  .plates {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.4rem;
  }

  .notes {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 2rem;
  }

  .footer-grid {
    grid-template-columns: 1.2fr 1fr 1fr;
    gap: 2.6rem;
  }

  .ledger-row {
    grid-template-columns: 3rem minmax(0, 1.6fr) minmax(0, 1fr);
    align-items: center;
    gap: 1.4rem;
  }

  .ledger-meta {
    grid-column: auto;
  }
}

@media (min-width: 940px) {
  .diptych {
    flex-direction: row;
    gap: 1.1rem;
    min-height: clamp(24rem, 46vh, 32rem);
  }

  .portal {
    min-height: 0;
  }

  .hero-body {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  }

  .plates {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .plate-wide {
    grid-column: span 2;
  }
}

@media (max-width: 679px) {
  .masthead-inner {
    padding-block: 0.8rem;
  }

  .nav {
    width: 100%;
    margin-left: 0;
    gap: 0.3rem;
    overflow-x: auto;
    scrollbar-width: none;
  }

  .nav::-webkit-scrollbar {
    display: none;
  }

  .nav a,
  .nav button {
    white-space: nowrap;
    padding: 0.4rem 0.6rem;
    font-size: 0.69rem;
    letter-spacing: 0.1em;
  }

  .status-chip {
    margin-left: auto;
  }
}

@media (prefers-contrast: more) {
  :root {
    --line: rgba(237, 231, 219, 0.32);
    --slate: #b3bccd;
    --bone-dim: #ded8cc;
  }
}