/* ============================================================
   PROJECT PHOSPHORUS
   A deliberate single-theme design: the night side of Venus.
   Every color is painted explicitly; nothing is inherited
   from the host. color-scheme is pinned so UI chrome agrees.
   ============================================================ */

:root {
  color-scheme: dark;

  /* Ground — violet-biased black, not neutral gray */
  --void:        #0A0912;
  --void-2:      #0E0C18;
  --deep:        #141223;
  --deep-2:      #1A1830;
  --line:        #2A2740;
  --line-soft:   #1F1D33;

  /* Ink — Venus' true cloud-top cream */
  --cream:       #F2E8D0;
  --cream-2:     #C9BFA8;
  --cream-dim:   #8B8373;
  --cream-faint: #5A5648;

  /* Warm axis: Venus, heat, acid, the band */
  --sulfur:      #E8B33A;
  --sulfur-deep: #A87D1F;
  --sulfur-wash: rgba(232, 179, 58, 0.10);
  --ember:       #FF7A45;
  --ember-wash:  rgba(255, 122, 69, 0.12);
  --furnace:     #C7381B;

  /* Cool axis: Earth, water, breathable air, crew */
  --aqua:        #5FD0C4;
  --aqua-deep:   #2E8F86;
  --aqua-wash:   rgba(95, 208, 196, 0.10);

  /* Semantic */
  --critical:    #E8574D;
  --high:        #E8964D;
  --medium:      #E8C84D;

  /* Type */
  --f-display: 'Archivo', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  --f-body:    'Spectral', Georgia, 'Times New Roman', serif;
  --f-mono:    'IBM Plex Mono', ui-monospace, 'SF Mono', Menlo, Consolas, monospace;

  --step--2: clamp(0.66rem, 0.63rem + 0.14vw, 0.74rem);
  --step--1: clamp(0.78rem, 0.74rem + 0.18vw, 0.88rem);
  --step-0:  clamp(0.98rem, 0.94rem + 0.22vw, 1.10rem);
  --step-1:  clamp(1.18rem, 1.10rem + 0.40vw, 1.42rem);
  --step-2:  clamp(1.45rem, 1.30rem + 0.75vw, 1.95rem);
  --step-3:  clamp(1.85rem, 1.55rem + 1.50vw, 2.90rem);
  --step-4:  clamp(2.30rem, 1.70rem + 3.00vw, 4.60rem);
  --step-5:  clamp(2.90rem, 1.90rem + 5.00vw, 7.00rem);

  --gutter: clamp(1rem, 4vw, 3rem);
  --rail-w: 0px;
  --shell: 1200px;
  --col: 64ch;
}

@media (min-width: 1100px) { :root { --rail-w: 84px; } }

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--void);
  color: var(--cream-2);
  font-family: var(--f-body);
  font-size: var(--step-0);
  line-height: 1.62;
  font-optical-sizing: auto;
  overflow-x: hidden;
}

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

a {
  color: var(--aqua);
  text-decoration-color: rgba(95, 208, 196, 0.35);
  text-underline-offset: 0.2em;
}
a:hover { text-decoration-color: var(--aqua); }
:focus-visible {
  outline: 2px solid var(--sulfur);
  outline-offset: 3px;
  border-radius: 2px;
}

h1, h2, h3, h4 {
  font-family: var(--f-display);
  color: var(--cream);
  font-weight: 600;
  line-height: 1.04;
  letter-spacing: -0.022em;
  text-wrap: balance;
  margin: 0;
}

p { margin: 0; }

/* ---------- shared atoms ---------------------------------- */

.eyebrow {
  font-family: var(--f-mono);
  font-size: var(--step--2);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--sulfur);
  margin: 0;
}
.eyebrow--aqua { color: var(--aqua); }
.eyebrow--dim  { color: var(--cream-dim); }

.num {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: 'tnum' 1;
}

.lede {
  font-size: var(--step-1);
  line-height: 1.5;
  color: var(--cream);
}

.note {
  font-size: var(--step--1);
  color: var(--cream-dim);
  line-height: 1.55;
}

.rule {
  height: 1px;
  background: var(--line);
  border: 0;
  margin: 0;
}

/* ---------- page frame ------------------------------------ */

.rail {
  position: fixed;
  left: 0; top: 0; bottom: 0;
  width: var(--rail-w);
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  padding-block: 1.4rem;
  border-right: 1px solid var(--line-soft);
  background: linear-gradient(180deg, var(--void) 0%, var(--void-2) 100%);
  z-index: 40;
}
@media (min-width: 1100px) { .rail { display: flex; } }

.rail__mark {
  font-family: var(--f-mono);
  font-size: var(--step--2);
  letter-spacing: 0.22em;
  color: var(--sulfur);
  writing-mode: vertical-rl;
  text-orientation: mixed;
}
.rail__track {
  flex: 1;
  width: 2px;
  margin-block: 1.5rem;
  background: var(--line);
  position: relative;
  border-radius: 2px;
}
.rail__fill {
  position: absolute;
  inset-inline: 0; top: 0;
  height: calc(var(--scroll, 0) * 100%);
  background: linear-gradient(180deg, var(--aqua) 0%, var(--sulfur) 55%, var(--ember) 100%);
  border-radius: 2px;
}
.rail__readout {
  font-family: var(--f-mono);
  font-size: var(--step--2);
  color: var(--cream-dim);
  writing-mode: vertical-rl;
  text-orientation: mixed;
  letter-spacing: 0.1em;
  max-height: 16rem;
  overflow: hidden;
}

.page { margin-left: var(--rail-w); }

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

section { position: relative; }

.band {
  padding-block: clamp(4rem, 11vh, 8rem);
  border-top: 1px solid var(--line-soft);
}
.band--flush { border-top: 0; }

.sec-head {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: clamp(2rem, 5vw, 3.5rem);
}
.sec-head h2 { font-size: var(--step-3); }
.sec-head__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 1.6rem;
  font-family: var(--f-mono);
  font-size: var(--step--2);
  color: var(--cream-dim);
  letter-spacing: 0.06em;
}

/* ---------- hero ------------------------------------------ */

.hero {
  position: relative;
  padding-block: clamp(3.5rem, 9vh, 7rem) clamp(3rem, 7vh, 5rem);
  overflow: hidden;
}
.hero__sky {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.hero__sky canvas { width: 100%; height: 100%; display: block; }
.hero__glow {
  position: absolute;
  right: -18vw; top: -12vh;
  width: min(78vw, 760px);
  aspect-ratio: 1;
  border-radius: 50%;
  background:
    radial-gradient(circle at 38% 34%, rgba(242, 232, 208, 0.85) 0%, rgba(232, 179, 58, 0.55) 34%, rgba(168, 125, 31, 0.18) 58%, transparent 71%);
  filter: blur(2px);
  opacity: 0.5;
  z-index: 0;
  transform: translate3d(0, calc(var(--scroll, 0) * 120px), 0);
  pointer-events: none;
}
.hero__inner { position: relative; z-index: 1; }

.hero__title {
  font-size: var(--step-5);
  font-weight: 700;
  letter-spacing: -0.045em;
  line-height: 0.88;
  color: var(--cream);
  margin-block: 1.2rem 0;
}
.hero__title span { display: block; }
.hero__title .t2 { color: var(--sulfur); }

.hero__sub {
  font-size: var(--step-1);
  line-height: 1.45;
  color: var(--cream);
  max-width: 46ch;
  margin-top: 1.6rem;
}
.hero__sub b { color: var(--sulfur); font-weight: 600; }

.hero__strip {
  display: flex;
  width: max-content;
  max-width: 100%;
  flex-wrap: wrap;
  gap: 1px;
  margin-top: clamp(2.5rem, 6vw, 4rem);
  background: var(--line-soft);
  border-block: 1px solid var(--line-soft);
}
.hero__stat {
  background: var(--void);
  padding: 1.1rem 1.2rem 1.2rem;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  min-height: 6.6rem;
}
.hero__stat dt {
  font-family: var(--f-mono);
  font-size: var(--step--2);
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--cream-dim);
}
.hero__stat dd {
  /* auto top margin bottom-aligns the figure, so numbers share a
     baseline even when a label wraps to two lines */
  margin: auto 0 0;
  font-family: var(--f-display);
  font-size: var(--step-2);
  font-weight: 600;
  letter-spacing: -0.03em;
  color: var(--cream);
  font-variant-numeric: tabular-nums;
}
.hero__stat dd small {
  font-size: 0.5em;
  font-weight: 500;
  color: var(--cream-dim);
  letter-spacing: 0;
}

.scroll-cue {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  margin-top: 2.4rem;
  font-family: var(--f-mono);
  font-size: var(--step--2);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cream-dim);
}
.scroll-cue i {
  width: 1px; height: 2.2rem;
  background: linear-gradient(180deg, var(--sulfur), transparent);
  animation: cue 2.4s ease-in-out infinite;
}
@keyframes cue { 0%,100% { opacity: 1; transform: scaleY(1); } 50% { opacity: .3; transform: scaleY(.55); } }

/* ---------- prose ----------------------------------------- */

.prose { display: flex; flex-direction: column; gap: 1.35rem; }
.prose p { max-width: var(--col); }
.prose strong { color: var(--cream); font-weight: 600; }

.pull {
  border-left: 2px solid var(--sulfur);
  padding: 0.4rem 0 0.4rem 1.5rem;
  font-size: var(--step-1);
  line-height: 1.45;
  color: var(--cream);
  max-width: 52ch;
}
.pull cite {
  display: block;
  margin-top: 0.7rem;
  font-family: var(--f-mono);
  font-size: var(--step--2);
  font-style: normal;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--cream-dim);
}

/* ---------- ledger (Venus vs Mars) ------------------------ */

.ledger__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.35rem 1rem;
  background: var(--void);
  padding: 1.1rem 0.2rem 1.2rem;
}
@media (min-width: 760px) {
  .ledger__row {
    grid-template-columns: minmax(0, 15rem) minmax(0, 8rem) minmax(0, 8rem) minmax(0, 1fr);
    align-items: baseline;
    padding-inline: 0.6rem;
  }
}
.ledger__metric {
  font-family: var(--f-display);
  font-weight: 600;
  font-size: var(--step-0);
  color: var(--cream);
  letter-spacing: -0.01em;
}
.ledger__v, .ledger__m {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--step--1);
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
}
.ledger__v::before, .ledger__m::before {
  font-size: 0.85em;
  letter-spacing: 0.1em;
  color: var(--cream-faint);
}
.ledger__v::before { content: 'V'; }
.ledger__m::before { content: 'M'; }
@media (min-width: 760px) {
  .ledger__v::before, .ledger__m::before { display: none; }
}
.ledger__v { color: var(--sulfur); }
.ledger__m { color: var(--cream-dim); }
.ledger__row[data-win="mars"] .ledger__v { color: var(--cream-dim); }
.ledger__row[data-win="mars"] .ledger__m { color: var(--aqua); }
.ledger__note { font-size: var(--step--1); color: var(--cream-dim); line-height: 1.5; }

.ledger__head {
  display: none;
  grid-template-columns: minmax(0, 15rem) minmax(0, 8rem) minmax(0, 8rem) minmax(0, 1fr);
  gap: 1rem;
  padding: 0 0.6rem 0.7rem;
  font-family: var(--f-mono);
  font-size: var(--step--2);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cream-faint);
  background: var(--void);
}
@media (min-width: 760px) { .ledger__head { display: grid; } }

/* duration bars */
.bar__seg--out   { background: linear-gradient(90deg, var(--aqua-deep), var(--aqua)); }
.bar__seg--stay  { background: var(--sulfur); }
.bar__seg--back  { background: linear-gradient(90deg, var(--sulfur-deep), rgba(168,125,31,.35)); }

/* ---------- scrollytelling stages ------------------------- */

.stage { position: relative; }
.stage__track { position: relative; }
.stage__viz {
  position: sticky;
  top: 0;
  height: 100svh;
  min-height: 520px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.stage__steps {
  position: relative;
  z-index: 3;
  pointer-events: none;
  margin-top: -100svh;
}
.stage__step {
  min-height: 88svh;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  gap: 0.9rem;
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.stage__card {
  pointer-events: auto;
  max-width: 34rem;
  background: rgba(10, 9, 18, 0.86);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid var(--line);
  border-left: 3px solid var(--sulfur);
  padding: clamp(1.2rem, 3vw, 1.9rem);
  display: flex; flex-direction: column; gap: 0.8rem;
}
.stage__card h3 { font-size: var(--step-2); }
.stage__card p { font-size: var(--step-0); color: var(--cream-2); }
.stage__card--aqua { border-left-color: var(--aqua); }
.stage__card--ember { border-left-color: var(--ember); }

/* ---------- descent stage --------------------------------- */

#descent .stage__viz { align-items: stretch; }
.descent { position: relative; width: 100%; height: 100%; }
.descent__sky {
  position: absolute; inset: 0;
  background: var(--sky, var(--void));
  transition: background .25s linear;
}
.descent__layers { position: absolute; inset: 0; overflow: hidden; }
.descent__deck {
  position: absolute;
  left: -10%; width: 120%;
  opacity: var(--o, 0);
  will-change: transform, opacity;
}
.descent__readout {
  position: absolute;
  right: var(--gutter);
  top: 50%;
  transform: translateY(-50%);
  z-index: 4;
  display: flex; flex-direction: column; gap: 0.8rem;
  background: rgba(10, 9, 18, 0.80);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--line);
  padding: 1rem 1.15rem;
  min-width: 11.5rem;
}
@media (max-width: 760px) {
  .descent__readout {
    right: 0; left: 0; top: auto; bottom: 0; transform: none; min-width: 0;
    flex-direction: row; flex-wrap: wrap; gap: 0.45rem 1.1rem;
    border: 0; border-top: 1px solid var(--line);
    padding: 0.7rem var(--gutter) 0.8rem;
  }
  .descent__readout .readout__v { font-size: var(--step-0); }
  #descent .stage__step { align-items: flex-start; padding-top: 7vh; }
}
.readout__row { display: flex; flex-direction: column; gap: 0.15rem; }
.readout__k {
  font-family: var(--f-mono); font-size: var(--step--2);
  letter-spacing: 0.16em; text-transform: uppercase; color: var(--cream-faint);
}
.readout__v {
  font-family: var(--f-mono); font-variant-numeric: tabular-nums;
  font-size: var(--step-1); color: var(--cream); line-height: 1.1;
}
.readout__v small { font-size: 0.55em; color: var(--cream-dim); margin-left: 0.3em; }
.readout__v[data-hot="1"] { color: var(--ember); }
.readout__v[data-band="1"] { color: var(--aqua); }

.descent__scale {
  position: absolute;
  left: var(--gutter); top: 0; bottom: 0;
  width: 2px; background: var(--line-soft);
  z-index: 3;
}
@media (max-width: 700px) { .descent__scale { display: none; } }
.descent__tick {
  position: absolute; left: 0;
  display: flex; align-items: center; gap: 0.5rem;
  transform: translateY(-50%);
  font-family: var(--f-mono); font-size: var(--step--2);
  color: var(--cream-faint); white-space: nowrap;
}
.descent__tick::before { content: ''; width: 10px; height: 1px; background: var(--line); }
.descent__tick[data-major] { color: var(--cream-dim); }
.descent__marker {
  position: absolute; left: -5px;
  width: 12px; height: 12px;
  transform: translateY(-50%) rotate(45deg);
  background: var(--sulfur);
  box-shadow: 0 0 0 4px rgba(232, 179, 58, 0.18);
}

/* ---------- timeline -------------------------------------- */

@media (min-width: 700px) { .phase__item { grid-template-columns: minmax(0, 13rem) minmax(0, 1fr); } }

/* ---------- laminate -------------------------------------- */

.laminate { display: flex; flex-direction: column; gap: 1px; background: var(--line-soft); }
.lam {
  background: var(--void); padding: 1rem 0.2rem 1.1rem;
  display: grid; gap: 0.3rem 1.4rem; grid-template-columns: 1fr;
  border-left: 3px solid var(--layercol, var(--line));
  padding-left: 1rem;
}
@media (min-width: 760px) { .lam { grid-template-columns: minmax(0, 16rem) minmax(0, 1fr); align-items: start; } }
.lam__n { font-family: var(--f-display); font-weight: 600; color: var(--cream); }
.lam__t { font-family: var(--f-mono); font-size: var(--step--2); color: var(--cream-dim); }
.lam__w { font-size: var(--step--1); color: var(--cream-2); line-height: 1.55; }

/* ---------- risks ----------------------------------------- */

.risks { display: flex; flex-direction: column; gap: 1px; background: var(--line-soft); }
.risk { background: var(--void); }
.risk__toggle {
  width: 100%; display: grid; grid-template-columns: 3rem minmax(0, 1fr) auto 1.4rem; gap: 0.6rem 1rem; align-items: center;
  background: none; border: 0; padding: clamp(1rem, 2.5vw, 1.4rem) 0; text-align: left; cursor: pointer; color: inherit; font: inherit;
}
.risk__toggle:hover .risk__n, .risk__toggle:focus-visible .risk__n { color: var(--sulfur); }
.risk__toggle:focus-visible { outline: 1px solid var(--sulfur); outline-offset: 4px; }
.risk__rank { font-family: var(--f-mono); font-size: var(--step--1); color: var(--cream-faint); letter-spacing: 0.1em; }
.risk__n { font-family: var(--f-display); font-weight: 600; font-size: var(--step-1); color: var(--cream); letter-spacing: -0.01em; transition: color .2s ease; }
.risk__sev {
  font-family: var(--f-mono); font-size: var(--step--2);
  letter-spacing: 0.16em; text-transform: uppercase;
  padding: 0.2rem 0.5rem; border: 1px solid currentColor; white-space: nowrap;
}
.risk__chev { font-family: var(--f-mono); font-size: var(--step-1); color: var(--cream-dim); text-align: center; line-height: 1; }
.risk.is-open .risk__chev { color: var(--sulfur); }
.risk[data-sev="critical"] .risk__sev { color: var(--critical); }
.risk[data-sev="high"] .risk__sev { color: var(--high); }
.risk[data-sev="medium"] .risk__sev { color: var(--medium); }
.risk[data-sev="structural"] .risk__sev { color: var(--cream-dim); }
.risk__body { display: grid; grid-template-rows: 0fr; transition: grid-template-rows .45s cubic-bezier(.2,.7,.3,1); }
.risk.is-open .risk__body { grid-template-rows: 1fr; }
.risk__inner { overflow: hidden; min-height: 0; display: flex; flex-direction: column; gap: 0.9rem; padding: 0 0 0 4rem; }
.risk.is-open .risk__inner { padding-bottom: clamp(1.2rem, 3vw, 1.8rem); }
.risk__what { color: var(--cream-2); max-width: 68ch; }
.risk__fix {
  padding-left: 1.1rem; border-left: 1px solid var(--line); max-width: 68ch;
  font-size: var(--step--1); color: var(--cream-dim); line-height: 1.6;
}
.risk__fix b { font-family: var(--f-mono); font-size: 0.9em; letter-spacing: 0.14em; text-transform: uppercase; color: var(--aqua); display: block; margin-bottom: 0.3rem; font-weight: 500; }
@media (max-width: 600px) {
  .risk__toggle { grid-template-columns: 2.4rem minmax(0, 1fr) 1.2rem; }
  .risk__sev { grid-column: 2; grid-row: 2; justify-self: start; }
  .risk__chev { grid-column: 3; grid-row: 1; }
  .risk__inner { padding-left: 0; }
}

/* ---------- what it costs, Venus against Mars ------------- */

.costvs { display: grid; gap: 1px; background: var(--line-soft); grid-template-columns: 1fr; }
@media (min-width: 640px) { .costvs { grid-template-columns: 1fr 1fr; } }
.costvs__col { background: var(--void); padding: clamp(1.4rem, 4vw, 2.4rem); display: flex; flex-direction: column; gap: 0.5rem; }
.costvs__col--venus { background: rgba(232, 179, 58, 0.05); }
.costvs__who { margin: 0; font-family: var(--f-mono); font-size: var(--step--2); letter-spacing: 0.18em; text-transform: uppercase; color: var(--cream-dim); }
.costvs__col--venus .costvs__who { color: var(--sulfur); }
.costvs__v { margin: 0; font-family: var(--f-display); font-size: clamp(2.6rem, 1.4rem + 5vw, 5.4rem); font-weight: 700; letter-spacing: -0.05em; line-height: 1; color: var(--cream); font-variant-numeric: tabular-nums; }
.costvs__col--venus .costvs__v { color: var(--sulfur); }
.costvs__k { margin: 0.2rem 0 0; font-family: var(--f-sans); font-weight: 600; font-size: var(--step-0); color: var(--cream); }
.costvs__d { margin: 0; font-size: var(--step--1); color: var(--cream-dim); line-height: 1.5; }


.compare { display: flex; flex-direction: column; gap: 1.4rem; }
.compare__row { display: flex; flex-direction: column; gap: 0.45rem; }
.compare__label { font-family: var(--f-mono); font-size: var(--step--2); color: var(--cream-dim); letter-spacing: 0.06em; line-height: 1.4; }
.compare__track { height: 18px; background: var(--deep); position: relative; }
.compare__fill { height: 100%; background: var(--cream-faint); }
.compare__row--venus .compare__fill { background: linear-gradient(90deg, var(--sulfur), var(--ember)); }
.compare__val { font-family: var(--f-mono); font-size: var(--step--1); color: var(--cream); font-variant-numeric: tabular-nums; }

/* ---------- sources / footer ------------------------------ */

.sources { display: flex; flex-direction: column; gap: 1px; background: var(--line-soft); }
.source {
  background: var(--void); padding: 0.8rem 0 0.85rem;
  display: grid; gap: 0.15rem 1.2rem; grid-template-columns: 1fr;
  font-size: var(--step--1);
}
@media (min-width: 700px) { .source { grid-template-columns: 8rem minmax(0, 1fr); align-items: baseline; } }
.source__tag { font-family: var(--f-mono); font-size: var(--step--2); letter-spacing: 0.16em; text-transform: uppercase; color: var(--sulfur); }
.source a { color: var(--cream-2); text-decoration-color: var(--line); }
.source a:hover { color: var(--cream); text-decoration-color: var(--sulfur); }

footer.foot {
  padding-block: 3rem 4rem;
  border-top: 1px solid var(--line-soft);
  display: flex; flex-direction: column; gap: 0.8rem;
}
.foot__mark { font-family: var(--f-mono); font-size: var(--step--2); letter-spacing: 0.24em; text-transform: uppercase; color: var(--sulfur); }

/* ---------- reveal (from a visible resting state) --------- */

.reveal { opacity: 0.999; transform: none; }
@media (prefers-reduced-motion: no-preference) {
  .reveal { transition: opacity .7s ease, transform .7s cubic-bezier(.2,.7,.3,1); }
  .reveal.is-armed { opacity: 0.35; transform: translate3d(0, 14px, 0); }
  .reveal.is-in { opacity: 1; transform: none; }
}

/* ---------- reduced motion -------------------------------- */

@media (prefers-reduced-motion: reduce) {
  .stage__viz { position: relative; height: auto; min-height: 0; padding-block: 2rem; }
  .stage__steps { margin-top: 0; }
  .stage__step { min-height: 0; padding-block: 1.5rem; }
  .edi-graphic { position: static; }
  .hero__glow { transform: none; }
  .scroll-cue i { animation: none; }
  .bar__seg, .costbar__fill, .compare__fill { transition: none; }
}

/* ---------- entry sequence -------------------------------- */

@media (min-width: 980px) {
  .edilayout { grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr); align-items: start; }
  .edi-graphic { position: sticky; top: 12vh; }
}

@media (min-width: 700px) { .edi { grid-template-columns: minmax(0, 9rem) minmax(0, 1fr); align-items: baseline; } }
.edi__h { display: flex; gap: 0.9rem; align-items: baseline; }
.edi__t { font-family: var(--f-mono); font-size: var(--step--1); color: var(--ember); letter-spacing: 0.04em; }
.edi__alt { font-family: var(--f-mono); font-size: var(--step--2); color: var(--cream-faint); }
.edi__n { font-size: var(--step-0); color: var(--cream); margin-bottom: 0.25rem; }
.edi__d { font-size: var(--step--1); color: var(--cream-2); line-height: 1.58; max-width: 58ch; }

/* ---------- voyage readout -------------------------------- */

#orbitSvg { width: 100%; height: 100%; display: flex; align-items: center; justify-content: center; }
#orbitSvg svg { max-height: 100%; }
@media (min-width: 1000px) {
  #orbitSvg { justify-content: flex-end; padding-left: 34%; padding-right: 3vw; }
}

.voyage__readout {
  position: absolute; left: var(--gutter); top: var(--gutter);
  z-index: 4; display: flex; flex-wrap: wrap; gap: 0.9rem 1.8rem;
  background: rgba(10, 9, 18, 0.82);
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--line); padding: 0.9rem 1.1rem;
  max-width: calc(100% - var(--gutter) * 2);
}

/* ---------- ISRU loops ------------------------------------ */

/* ---------- lift calculator ------------------------------- */

@media (min-width: 700px) { .calc { grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr); align-items: center; } }

input[type="range"] {
  -webkit-appearance: none; appearance: none;
  width: 100%; height: 30px; background: transparent; cursor: pointer; margin: 0;
}
input[type="range"]::-webkit-slider-runnable-track {
  height: 4px; background: linear-gradient(90deg, var(--ember) 0%, var(--sulfur) 26%, var(--aqua) 44%, var(--sulfur) 62%, var(--line) 100%);
}
input[type="range"]::-moz-range-track {
  height: 4px; background: linear-gradient(90deg, var(--ember) 0%, var(--sulfur) 26%, var(--aqua) 44%, var(--sulfur) 62%, var(--line) 100%);
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none;
  width: 18px; height: 18px; margin-top: -7px; border-radius: 50%;
  background: var(--cream); border: 2px solid var(--void);
  box-shadow: 0 0 0 3px rgba(242, 232, 208, 0.25);
}
input[type="range"]::-moz-range-thumb {
  width: 16px; height: 16px; border-radius: 50%;
  background: var(--cream); border: 2px solid var(--void);
  box-shadow: 0 0 0 3px rgba(242, 232, 208, 0.25);
}

/* ---------- misc ------------------------------------------ */

@media (min-width: 860px) { .two { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); } }

.factgrid { display: grid; gap: 1px; background: var(--line-soft); grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); }
.fact { background: var(--void); padding: 1rem 1.1rem 1.2rem; display: flex; flex-direction: column; gap: 0.3rem; }
.fact dt { font-family: var(--f-mono); font-size: var(--step--2); letter-spacing: 0.13em; text-transform: uppercase; color: var(--cream-dim); }
.fact dd { margin: 0; font-family: var(--f-mono); font-size: var(--step-1); color: var(--cream); font-variant-numeric: tabular-nums; }

#shipSvg { width: 100%; overflow-x: auto; }
#shipSvg svg { min-width: 900px; }

/* ---------- voyage stage placement (must follow the base rules) ---- */

@media (min-width: 1000px) {
  /* keep the plot clear of the narrative cards */
  #orbitSvg svg { max-height: 84%; }
  #act2 .stage__card { max-width: 30rem; }
}

@media (max-width: 760px) {
  .voyage__readout {
    left: 0; right: 0; top: auto; bottom: 0; max-width: none;
    border-inline: 0; border-bottom: 0;
    gap: 0.45rem 1.4rem;
    padding: 0.7rem var(--gutter) 0.8rem;
  }
  .voyage__readout .readout__v { font-size: var(--step-0); }
  #act2 .stage__step { align-items: flex-start; padding-top: 5vh; }
  #orbitSvg { align-items: flex-start; padding-top: 3vh; padding-bottom: 7.5rem; }
}

/* ============================================================
   HOW IT FLOATS
   ============================================================ */

.floats { display: grid; gap: 1px; background: var(--line-soft); grid-template-columns: 1fr; }
@media (min-width: 700px) { .floats { grid-template-columns: 1fr 1fr; } }
.floats__col { background: var(--void); display: grid; grid-template-columns: 1fr 1fr; gap: 1px; background: var(--line-soft); }
.floats__h { grid-column: 1 / -1; margin: 0; background: var(--void); padding: 0.9rem 0.95rem; display: flex; flex-wrap: wrap; gap: 0.3rem 0.9rem; align-items: baseline; }
.floats__h b { font-family: var(--f-display); font-weight: 600; color: var(--sulfur); font-size: var(--step-1); }
.floats__h span { font-family: var(--f-mono); font-size: var(--step--2); color: var(--cream-dim); letter-spacing: 0.06em; }
.floats__cell { background: var(--void); padding: 0.85rem 0.95rem; display: flex; flex-direction: column; gap: 0.2rem; }
.floats__cell dt { font-family: var(--f-mono); font-size: var(--step--2); letter-spacing: 0.13em; text-transform: uppercase; color: var(--cream-dim); }
.floats__cell dd { margin: 0; font-family: var(--f-mono); font-size: var(--step-1); color: var(--cream); font-variant-numeric: tabular-nums; }
.floats__cell dd span + span { font-size: 0.55em; color: var(--cream-dim); margin-left: 0.35em; }
.floats__cell--hero { grid-column: 1 / -1; }
.floats__cell--hero dd { color: var(--sulfur); font-size: var(--step-2); }
@media (max-width: 760px) {
  .sk { grid-template-columns: 2.8rem 1fr 6.4rem; gap: 0.6rem; }
}

/* ============================================================
   EXPERIENCE + CREW
   ============================================================ */

/* ============================================================
   THE THREE ACTS
   ============================================================ */

.act .stage__viz { background: var(--void); }
#assemblyCanvas, #journeyCanvas, .act3d {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
}
.act__fade { position: absolute; inset: 0; background: var(--void); opacity: 0; pointer-events: none; z-index: 2; }
.act__caption {
  position: absolute; left: var(--gutter); bottom: clamp(1.2rem, 4vh, 2.4rem); z-index: 4; margin: 0;
  font-family: var(--f-mono); font-size: var(--step--1); color: var(--cream);
  letter-spacing: 0.04em; padding: 0.55rem 0.8rem;
  background: rgba(10, 9, 18, 0.72); border-left: 2px solid var(--aqua);
  max-width: min(60vw, 30rem);
}
.act__caption.is-final { border-left-color: var(--sulfur); }
.act__caption:empty { display: none; }
.descent__3d { position: absolute; inset: 0; width: 100%; height: 100%; z-index: 1; pointer-events: none; }

/* the ship, cut away in three dimensions */
@media (max-width: 760px) {
  .cut3d { aspect-ratio: 4 / 4.2; }
  .cut3d__label { max-width: 38%; padding: 0.25rem 0.4rem; }
  .cut3d__label b { font-size: var(--step--2); }
  .cut3d__label span { font-size: 0.62rem; }
  .cut3d__scale { display: none; }
  .act__caption { max-width: calc(100vw - 2 * var(--gutter)); bottom: 6.5rem; }
}

/* How it gets made: cut, fold, inflate, fill */
.build .stage__viz { background: var(--void); }
#buildCanvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.build .stage__step { min-height: 92svh; }
.build .stage__card { max-width: 31rem; }
.bcard__step {
  display: flex; flex-wrap: wrap; gap: 0.4rem 1rem; align-items: baseline; margin: 0;
  font-family: var(--f-display); font-size: var(--step-2); font-weight: 700; color: var(--sulfur); letter-spacing: -0.01em;
}
.bcard__where { font-family: var(--f-mono); font-size: var(--step--2); font-weight: 400; color: var(--cream-dim); letter-spacing: 0.06em; }
.bcard h3 { font-size: var(--step-1); }
.bcard__fig { margin: 0.2rem 0 0; padding-top: 0.8rem; border-top: 1px solid var(--line); display: flex; align-items: baseline; gap: 0.7rem; flex-wrap: wrap; }
.bcard__fig b { font-family: var(--f-mono); font-size: var(--step-2); font-weight: 500; color: var(--sulfur); font-variant-numeric: tabular-nums; }
.bcard__fig span { font-family: var(--f-mono); font-size: var(--step--2); color: var(--cream-faint); letter-spacing: 0.08em; text-transform: uppercase; }
.build__hud { min-width: 13rem; }

/* walking on sunshine */
.band--tight { padding-bottom: 0; }
.walk .stage__viz { background: var(--void); }
#walkCanvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.walk .stage__step { min-height: 78svh; }
.walk .stage__card { max-width: 30rem; }
.walk .act__badge, .walk .act__badge span { color: var(--void); }
.walk .act__badge { opacity: 0.7; transition: color .6s ease; }
.walk.is-night .act__badge, .walk.is-night .act__badge span { color: var(--cream); }
.walk__hud { min-width: 13rem; }

/* what we'd learn, and where the samples come from */
.learn .stage__viz, .samples .stage__viz { background: var(--void); }
#learnCanvas, #samplesCanvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.learn .stage__step { min-height: 90svh; }
.samples .stage__step { min-height: 80svh; }
.samples .stage__card { max-width: 30rem; }
.qcard { display: grid; gap: 1px; background: var(--line-soft); margin-top: 0.2rem; }
.qcard__col { background: rgba(10, 9, 18, 0.6); padding: 0.8rem 0.9rem 0.9rem; display: flex; flex-direction: column; gap: 0.35rem; }
.qcard__k { font-family: var(--f-mono); font-size: var(--step--2); letter-spacing: 0.14em; text-transform: uppercase; color: var(--cream-faint); }
.qcard__col--crew { background: rgba(95, 208, 196, 0.06); }
.qcard__col--crew .qcard__k { color: var(--aqua); }
.stage__card .qcard__v { font-size: var(--step--1); line-height: 1.55; color: var(--cream-dim); }
.stage__card .qcard__col--crew .qcard__v { color: var(--cream-2); }
.bcard__kit { margin: 0; padding-top: 0.8rem; border-top: 1px solid var(--line); font-family: var(--f-mono); font-size: var(--step--2); color: var(--sulfur); letter-spacing: 0.03em; }
.stage__card--aqua .bcard__kit, .stage__card--aqua .bcard__step { color: var(--aqua); }
.samples__hud { min-width: 12rem; }

/* the fleet, exploded */
.fspecs { margin-top: 0.2rem; display: flex; flex-direction: column; border-top: 1px solid var(--line); }
.fspecs__toggle {
  display: flex; justify-content: space-between; align-items: center; gap: 1rem; width: 100%;
  background: none; border: 0; padding: 0.55rem 0; text-align: left; cursor: pointer; color: var(--aqua); font: inherit;
  font-family: var(--f-mono); font-size: var(--step--2); letter-spacing: 0.1em; text-transform: uppercase;
}
.fspecs__toggle i { font-style: normal; font-size: var(--step-0); color: var(--cream-dim); }
.fspecs__toggle:focus-visible { outline: 1px solid var(--aqua); outline-offset: 3px; }
.stage__card--ember .fspecs__toggle { color: var(--ember); }
.stage__card:not(.stage__card--aqua):not(.stage__card--ember) .fspecs__toggle { color: var(--sulfur); }
.fspecs__body { display: none; padding-bottom: 0.4rem; }
.fspecs.is-open .fspecs__body { display: block; }
.fspec--head span { color: var(--cream); }
.fspec--head b { color: var(--sulfur); }
.stage__card--aqua .fspec--head b { color: var(--aqua); }
.stage__card--ember .fspec--head b { color: var(--ember); }
.fspec__line { margin: 0; padding: 0.4rem 0; font-size: var(--step--1); color: var(--cream-dim); }
.stage__card .laminate, .stage__card .floats { margin-top: 0.2rem; }
.stage__card .lam { padding: 0.55rem 0 0.6rem 0.8rem; grid-template-columns: 1fr; gap: 0.15rem; }
.stage__card .lam > div { display: flex; flex-wrap: wrap; gap: 0.2rem 0.7rem; align-items: baseline; }
.stage__card .floats__col { grid-template-columns: 1fr 1fr; }
.stage__card .floats__cell { padding: 0.55rem 0.7rem; }
.stage__card .floats__cell dd { font-size: var(--step-0); }
.stage__card .floats__cell--hero dd { font-size: var(--step-1); }
.stage__card .floats__h { padding: 0.6rem 0.7rem; }
.fspec { margin: 0; display: flex; justify-content: space-between; gap: 1rem; padding: 0.3rem 0; border-bottom: 1px solid var(--line-soft); font-family: var(--f-mono); font-size: var(--step--2); color: var(--cream-dim); }
.fspec b { font-weight: 500; color: var(--cream); text-align: right; font-variant-numeric: tabular-nums; }
.fdl { display: inline-block; margin-top: 0.7rem; font-family: var(--f-mono); font-size: var(--step--2); letter-spacing: 0.08em; text-transform: uppercase; color: var(--aqua); text-decoration: none; border-bottom: 1px solid currentColor; }

/* thirty days, lap by lap */
.stay .stage__viz { background: var(--void); }
#stayCanvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.stay .stage__step { min-height: 82svh; }
.stay .stage__card { max-width: 30rem; }
.stay__hud { min-width: 13rem; }

/* chasing the sun: the ship close up, one day and one night */
.chase .stage__viz { background: var(--void); }
#chaseCanvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.chase .stage__step { min-height: 80svh; }
.chase .stage__card { max-width: 30rem; }
.chase .act__badge, .chase .act__badge span { color: var(--void); }
.chase .act__badge { opacity: 0.7; transition: color .6s ease; }
.chase.is-night .act__badge, .chase.is-night .act__badge span { color: var(--cream); }
.chase__hud { min-width: 13rem; }

/* the program: a timeline that runs as you scroll */
.program .stage__viz { background: var(--void); }
#programCanvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.program .stage__step { min-height: 96svh; }
.program .stage__card { max-width: 32rem; }
.program .journey__hud { top: auto; bottom: clamp(1rem, 4vh, 2.5rem); transform: none; min-width: 13rem; }
.pitems { display: flex; flex-direction: column; border-top: 1px solid var(--line); margin-top: 0.2rem; }
.pitem { padding: 0.55rem 0; border-bottom: 1px solid var(--line-soft); display: flex; flex-direction: column; gap: 0.15rem; }
.pitem__n { margin: 0; display: flex; flex-wrap: wrap; gap: 0.2rem 0.7rem; align-items: baseline; font-size: var(--step--1) !important; }
.pitem__n b { font-family: var(--f-sans); font-weight: 600; color: var(--cream); }
.pitem__n span { font-family: var(--f-mono); font-size: var(--step--2); color: var(--cream-dim); }
.stage__card .pitem__d { font-size: var(--step--1); color: var(--cream-dim); line-height: 1.5; }
@media (max-width: 760px) {
  #build .stage__step, #walk .stage__step, #samples .stage__step, #stay .stage__step, #chase .stage__step, #act1 .stage__step { align-items: flex-start; padding-top: 4vh; }
  #act1 .stage__step { min-height: 80svh; }
  #act1 .stage__card { max-width: 100%; }
  .program .stage__step { align-items: flex-start; padding-top: 4vh; }
  .program .journey__hud { display: none; }
  .learn .stage__viz { height: 42svh; min-height: 0; z-index: 4; }
  .learn .stage__steps { margin-top: 0; }
  .learn .stage__step { min-height: 58svh; }
  .learn .act__badge { display: none; }
}

/* Venus against Mars: the comparison stage */
.compare .stage__viz { background: var(--void); }
#compareCanvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.compare .stage__step { min-height: 64svh; }
.cmp__metric { font-family: var(--f-mono); font-size: var(--step--2); letter-spacing: 0.16em; text-transform: uppercase; color: var(--cream-dim); }
.cmp__vals { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; background: var(--line-soft); }
.cmp__val { background: var(--void); padding: 0.75rem 0.9rem 0.85rem; display: flex; flex-direction: column; gap: 0.3rem; }
.cmp__who { font-family: var(--f-mono); font-size: var(--step--2); letter-spacing: 0.14em; text-transform: uppercase; color: var(--cream-faint); }
.cmp__n { font-family: var(--f-mono); font-variant-numeric: tabular-nums; font-size: var(--step-2); line-height: 1.1; color: var(--cream-dim); font-weight: 500; }
.cmp__val--v .cmp__n { color: var(--sulfur); }
.cmp[data-win="mars"] .cmp__val--v .cmp__n { color: var(--cream-dim); }
.cmp[data-win="mars"] .cmp__val--m .cmp__n { color: var(--aqua); }
.cmp__n { opacity: 0; transform: translateY(0.3em); transition: opacity .5s ease, transform .5s ease; }
.cmp.is-done .cmp__n { opacity: 1; transform: none; }
.cmp__note { font-size: var(--step-0); color: var(--cream-2); margin: 0; }
.cmp__call {
  position: absolute; left: 0; top: 0; z-index: 3; pointer-events: none;
  transform: translate(-50%, -100%); opacity: 0; transition: opacity .35s ease;
  max-width: 15rem; text-align: center;
  font-family: var(--f-mono); font-size: var(--step--2); line-height: 1.4; color: var(--cream);
  background: rgba(10, 9, 18, 0.78); padding: 0.4rem 0.6rem;
}
.cmp__call.is-on { opacity: 1; }
.cmp__call--v { border-bottom: 2px solid var(--sulfur); }
.cmp__call--m { border-bottom: 2px solid var(--ember); }
.cmp__name {
  position: absolute; left: 0; top: 0; z-index: 3; pointer-events: none; transform: translate(-50%, 0);
  font-family: var(--f-display); font-size: var(--step-1); font-weight: 600; letter-spacing: -0.01em; color: var(--cream);
}
.cmp__lines { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; z-index: 2; }
.cmp__lines line { stroke-width: 1.2; opacity: 0; transition: opacity .35s ease; }
.cmp__lines line.is-on { opacity: 0.6; }
.cmp__lines circle { opacity: 0; transition: opacity .35s ease; }
.cmp__lines circle.is-on { opacity: 1; }
@media (max-width: 760px) {
  /* phones: the planets hold a band at the top and the cards scroll beneath it */
  .compare .stage__viz { height: 42svh; min-height: 0; z-index: 4; }
  .compare .stage__steps { margin-top: 0; }
  .compare .stage__step { min-height: 58svh; justify-content: center; }
  .compare .act__badge { display: none; }
  .cmp__call { max-width: 9.6rem; font-size: 0.7rem; padding: 0.3rem 0.4rem; }
  .cmp__n { font-size: var(--step-1); }
}

.act__badge {
  position: absolute;
  top: clamp(1rem, 3vh, 2rem);
  left: var(--gutter);
  z-index: 4;
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  font-family: var(--f-mono);
  font-size: var(--step--2);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--cream-dim);
  margin: 0;
}
.act__badge span {
  font-family: var(--f-display);
  font-size: var(--step-2);
  font-weight: 700;
  letter-spacing: -0.04em;
  color: var(--sulfur);
}

/* the benefit chips that layer in as the story moves */
.benefit {
  pointer-events: auto;
  max-width: 30rem;
  border-left: 2px solid var(--aqua);
  background: rgba(10, 9, 18, 0.82);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 0.85rem 1.1rem 0.95rem;
  font-size: var(--step--1);
  line-height: 1.55;
  color: var(--cream-dim);
}
.benefit b {
  display: block;
  font-family: var(--f-display);
  font-weight: 600;
  font-size: var(--step-0);
  color: var(--aqua);
  margin-bottom: 0.2rem;
  letter-spacing: -0.01em;
}
.benefit--stack { border-left-color: var(--sulfur); }
.benefit--stack b { color: var(--sulfur); }

/* the day / place readout on act 02 */
.journey__hud {
  position: absolute;
  right: var(--gutter);
  top: 50%;
  transform: translateY(-50%);
  z-index: 4;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  min-width: 12rem;
  max-width: 16rem;
  background: rgba(10, 9, 18, 0.82);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--line);
  padding: 1rem 1.15rem 1.1rem;
}
.journey__note:empty { display: none; }
.journey__note {
  font-size: var(--step--1);
  color: var(--cream-dim);
  line-height: 1.5;
  border-top: 1px solid var(--line-soft);
  padding-top: 0.7rem;
  margin: 0;
}
.readout__v--sm { font-size: var(--step-0) !important; }

@media (max-width: 760px) {
  .journey__hud {
    z-index: 2;
    right: 0; left: 0; top: auto; bottom: 0;
    transform: none;
    max-width: none;
    border-inline: 0; border-bottom: 0;
    flex-direction: row; flex-wrap: wrap; align-items: baseline;
    gap: 0.4rem 1.4rem;
    padding: 0.7rem var(--gutter) 0.85rem;
  }
  .journey__note { border-top: 0; padding-top: 0; flex: 1 1 100%; }
  #act2 .stage__step { align-items: flex-start; padding-top: 6vh; }
  .act__badge { top: 0.8rem; }
  .benefit { max-width: none; }
}

@media (prefers-reduced-motion: reduce) {
  .journey__hud { position: static; transform: none; margin: 1rem auto 0; }
  .act__badge { position: static; margin-bottom: 1rem; }
}

/* ============================================================
   THE FLEET IN 3D
   ============================================================ */

@media (max-width: 760px) {
  .f3d__label { position: static; max-width: none; padding: 0.9rem 0.9rem 0; }
  .f3d__stage { display: flex; flex-direction: column; aspect-ratio: auto; max-height: none; }
  .f3d__stage canvas { position: relative; aspect-ratio: 4 / 3; height: auto; }
}

/* phones: nothing under eleven pixels, spec rows stacked */
@media (max-width: 480px) {
  :root { --step--2: 0.72rem; }
  .readout__v small { font-size: 0.62em; }
  .floats__cell dd span + span { font-size: 0.66em; }
  .fspec { flex-direction: column; gap: 0.05rem; }
  .fspec b { text-align: left; }
  .costvs__v { font-size: clamp(2.4rem, 12vw, 3.4rem); }
}