/* ==========================================================================
   7,83 Hz — La nota de fondo de la Tierra
   Editorial científico: papel cálido, tinta azulada, ámbar de energía.
   ========================================================================== */

/* ---------- Tipografías (locales, sin CDN) ---------- */
@font-face {
  font-family: "Fraunces";
  src: url("assets/fonts/fraunces-v38-latin_latin-ext-900.woff2") format("woff2");
  font-weight: 900; font-style: normal; font-display: swap;
}
@font-face {
  font-family: "Fraunces";
  src: url("assets/fonts/fraunces-v38-latin_latin-ext-600.woff2") format("woff2");
  font-weight: 600; font-style: normal; font-display: swap;
}
@font-face {
  font-family: "Fraunces";
  src: url("assets/fonts/fraunces-v38-latin_latin-ext-italic.woff2") format("woff2");
  font-weight: 400; font-style: italic; font-display: swap;
}
@font-face {
  font-family: "Source Serif";
  src: url("assets/fonts/source-serif-4-v14-latin_latin-ext-regular.woff2") format("woff2");
  font-weight: 400; font-style: normal; font-display: swap;
}
@font-face {
  font-family: "Source Serif";
  src: url("assets/fonts/source-serif-4-v14-latin_latin-ext-italic.woff2") format("woff2");
  font-weight: 400; font-style: italic; font-display: swap;
}
@font-face {
  font-family: "Source Serif";
  src: url("assets/fonts/source-serif-4-v14-latin_latin-ext-700.woff2") format("woff2");
  font-weight: 700; font-style: normal; font-display: swap;
}

/* ---------- Paleta ---------- */
:root {
  --paper: #f6f1e5;
  --paper-fig: #fdfaf2;
  --card: #fffdf6;
  --ink: #21313c;
  --ink-soft: #64707a;
  --line: #ddd2bc;

  --sky: #2b6e93;
  --sky-wash: #dcebf2;
  --earth: #3f6b4f;
  --earth-hi: #5d8a6b;
  --earth-soft: #cfdcc9;
  --amber: #d9912b;
  --amber-bright: #f2b33d;
  --amber-hot: #f2a51f;
  --rust: #b0562f;
  --cloud: #c9d4dc;
  --cloud-hi: #dde5ea;
  --screen: #16232d;

  --ok: #3f6b4f;
  --warn: #a05a1c;

  --font-display: "Fraunces", Georgia, serif;
  --font-body: "Source Serif", Georgia, serif;
  --font-data: "Fraunces", Georgia, serif;

  --radius: 18px;
  --shadow: 0 2px 6px rgba(33, 49, 60, 0.06), 0 14px 34px rgba(33, 49, 60, 0.07);
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #131a20;
    --paper-fig: #1a232b;
    --card: #1b252e;
    --ink: #e9e2d0;
    --ink-soft: #9aa6ad;
    --line: #33404a;

    --sky: #6da9c9;
    --sky-wash: #1e2f3a;
    --earth: #4e7d5f;
    --earth-hi: #659a78;
    --earth-soft: #2c4034;
    --amber: #e3a049;
    --amber-bright: #f2b33d;
    --amber-hot: #f5b83f;
    --rust: #c76a41;
    --cloud: #45525c;
    --cloud-hi: #57656f;
    --screen: #0d151c;

    --ok: #7fb894;
    --warn: #dfa568;

    --shadow: 0 2px 6px rgba(0, 0, 0, 0.3), 0 14px 34px rgba(0, 0, 0, 0.35);
  }
}

/* ---------- Base ---------- */
* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--paper);
  background-image: radial-gradient(circle at 12% -4%, rgba(43, 110, 147, 0.07), transparent 42%),
                    radial-gradient(circle at 90% 8%, rgba(217, 145, 43, 0.06), transparent 38%);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 1.075rem;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.12;
  letter-spacing: -0.015em;
  margin: 0;
}

a { color: var(--sky); }

.skip-link {
  position: absolute; left: -999px; top: 0;
  background: var(--ink); color: var(--paper);
  padding: 0.6rem 1rem; z-index: 100; border-radius: 0 0 10px 0;
}
.skip-link:focus { left: 0; }

:focus-visible {
  outline: 3px solid var(--amber);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0.55rem 1.1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.brand { text-decoration: none; color: var(--ink); display: flex; align-items: baseline; gap: 0.55rem; min-width: 0; }
.brand-hz {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.35rem;
  color: var(--amber);
  white-space: nowrap;
}
.brand-sub {
  font-size: 0.82rem;
  color: var(--ink-soft);
  font-style: italic;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
@media (max-width: 560px) { .brand-sub { display: none; } }

/* ---------- Toggle esfera/domo ---------- */
#modelSwitch {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  border: 1.5px solid var(--line);
  background: var(--card);
  border-radius: 999px;
  padding: 0.4rem 0.85rem;
  cursor: pointer;
  font: inherit;
  font-size: 0.92rem;
  color: var(--ink-soft);
  box-shadow: var(--shadow);
  transition: border-color 0.25s;
}
#modelSwitch:hover { border-color: var(--amber); }
#modelSwitch .opt { display: flex; align-items: center; gap: 0.35rem; font-weight: 700; transition: color 0.25s; }
#modelSwitch .knob {
  width: 42px; height: 22px;
  border-radius: 999px;
  background: var(--line);
  position: relative;
  flex: none;
  transition: background 0.3s;
}
#modelSwitch .knob::after {
  content: "";
  position: absolute;
  top: 3px; left: 3px;
  width: 16px; height: 16px;
  border-radius: 50%;
  background: var(--amber);
  transition: transform 0.3s cubic-bezier(0.6, 0, 0.3, 1.4);
}
body[data-model="esfera"] .opt-esfera { color: var(--sky); }
body[data-model="domo"] .opt-domo { color: var(--earth); }
body[data-model="domo"] #modelSwitch .knob::after { transform: translateX(20px); }
@media (max-width: 420px) {
  #modelSwitch { padding: 0.35rem 0.6rem; font-size: 0.84rem; gap: 0.45rem; }
  #modelSwitch .knob { width: 34px; }
  body[data-model="domo"] #modelSwitch .knob::after { transform: translateX(12px); }
}

/* ---------- Vistas por modelo ---------- */
.model-stage { position: relative; }
.model-stage .model-view {
  transition: opacity 0.55s ease, transform 0.55s ease;
}
.model-stage .model-view.view-domo { position: absolute; inset: 0; }

body[data-model="esfera"] .model-stage .view-domo,
body[data-model="domo"] .model-stage .view-esfera {
  opacity: 0;
  transform: scale(0.94);
  pointer-events: none;
}
body[data-model="esfera"] .model-stage .view-esfera,
body[data-model="domo"] .model-stage .view-domo {
  opacity: 1;
  transform: scale(1);
}

/* texto condicional por modelo */
span.model-esfera, span.model-domo { display: none; }
body[data-model="esfera"] span.model-esfera { display: inline; }
body[data-model="domo"] span.model-domo { display: inline; }

/* insets chicos (sección 5) */
.path-inset { position: relative; max-width: 300px; margin: 0 auto 0.4rem; }
.path-inset .model-view { width: 100%; height: auto; display: block; }
.path-inset .view-domo { position: absolute; inset: 0; }
.path-inset .model-view { transition: opacity 0.5s ease; }
body[data-model="esfera"] .path-inset .view-domo,
body[data-model="domo"] .path-inset .view-esfera { opacity: 0; pointer-events: none; }

/* ---------- Hero ---------- */
.hero {
  max-width: 1100px;
  margin: 0 auto;
  padding: 3.4rem 1.2rem 2.2rem;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 2.6rem;
  align-items: center;
}
.kicker {
  font-family: var(--font-body);
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--amber);
  margin: 0 0 1rem;
}
.hero h1 {
  font-size: clamp(2rem, 4.6vw, 3.3rem);
  margin-bottom: 1.3rem;
}
.hero h1 em {
  font-style: italic;
  font-weight: 400;
  color: var(--sky);
}
.lede { font-size: 1.12rem; color: var(--ink); max-width: 34em; margin: 0; }

.hero-figure {
  margin: 0;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1rem 1rem 0.4rem;
}
.hero-figure svg { width: 100%; height: auto; display: block; }
.hero-figure figcaption {
  font-size: 0.9rem;
  color: var(--ink-soft);
  padding: 0.5rem 0.4rem 0.8rem;
  font-style: italic;
}

.toc { grid-column: 1 / -1; margin-top: 1.4rem; }
.toc ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin: 0; padding: 0;
  counter-reset: toc;
}
.toc a {
  counter-increment: toc;
  display: inline-block;
  text-decoration: none;
  color: var(--ink-soft);
  border: 1px solid var(--line);
  background: var(--card);
  border-radius: 999px;
  padding: 0.3rem 0.85rem;
  font-size: 0.86rem;
  transition: color 0.2s, border-color 0.2s;
}
.toc a::before {
  content: counter(toc, decimal-leading-zero) " · ";
  color: var(--amber);
  font-weight: 700;
}
.toc a:hover, .toc a.active { color: var(--ink); border-color: var(--amber); }

@media (max-width: 860px) {
  .hero { grid-template-columns: 1fr; gap: 1.8rem; padding-top: 2.4rem; }
}

/* ---------- Capítulos ---------- */
.chapter {
  max-width: 1100px;
  margin: 0 auto;
  padding: 3.6rem 1.2rem 1.4rem;
}
.chapter-head {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  border-top: 1px solid var(--line);
  padding-top: 1.6rem;
  margin-bottom: 1.6rem;
}
.chapter-num {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 2.4rem;
  color: var(--amber);
  opacity: 0.85;
  line-height: 1;
}
.chapter-head h2 { font-size: clamp(1.5rem, 3vw, 2.15rem); }

.chapter-body {
  display: grid;
  grid-template-columns: minmax(0, 0.94fr) minmax(0, 1.06fr);
  gap: 2.4rem;
  align-items: start;
}
.chapter-body-full { display: block; }
@media (max-width: 860px) {
  .chapter-body { grid-template-columns: 1fr; gap: 1.6rem; }
  .chapter { padding-top: 2.6rem; }
}

.prose p { margin: 0 0 1.05rem; }
.prose p:last-child { margin-bottom: 0; }
.fact-list { margin: 0 0 1.05rem; padding-left: 1.2rem; }
.fact-list li { margin-bottom: 0.4rem; }
.hint {
  font-size: 0.92rem;
  color: var(--amber);
  font-weight: 700;
}
.hint::before { content: "→ "; }

/* ---------- Figuras / tarjetas ---------- */
.fig-card {
  margin: 0;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.1rem 1.1rem 0.6rem;
}
.fig-card > svg, .fig-card figure > svg { width: 100%; height: auto; display: block; }
.fig-card figcaption {
  font-size: 0.88rem;
  color: var(--ink-soft);
  font-style: italic;
  padding: 0.7rem 0.3rem 0.6rem;
  border-top: 1px dashed var(--line);
  margin-top: 0.7rem;
}

/* texto dentro de SVG */
svg text {
  font-family: var(--font-body);
  font-size: 15px;
  fill: var(--ink);
}
.fig-label text, .fig-note { font-size: 14px; fill: var(--ink-soft); }
p.fig-note { color: var(--ink-soft); font-size: 0.9rem; margin: 0.4rem 0 0; }
.fig-note.strong, .strong { font-weight: 700; fill: var(--ink); }
p.fig-note.strong { color: var(--ink); }
.on-earth { fill: #f2ecd9; font-weight: 700; letter-spacing: 0.08em; font-size: 16px; }
.layer-name { fill: #f6f1e5; font-weight: 700; letter-spacing: 0.14em; font-size: 16px; }
.big-number { font-family: var(--font-display); font-weight: 900; font-size: 58px; fill: var(--amber); }
.big-unit { font-family: var(--font-display); font-weight: 600; font-size: 30px; fill: var(--amber); }
.step-val { font-family: var(--font-display); font-weight: 900; font-size: 19px; fill: var(--ink); text-anchor: middle; }
.screen-text { fill: var(--amber-bright); font-weight: 700; font-size: 16px; }

/* ---------- Interactivo: capacitor ---------- */
.cap-layer { cursor: pointer; }
.cap-layer rect { transition: filter 0.2s, transform 0.2s; }
.cap-layer:hover rect, .cap-layer:focus-visible rect { filter: brightness(1.12); }
.cap-layer .charges {
  opacity: 0;
  transition: opacity 0.45s ease;
}
.cap-layer .charges text {
  font-weight: 900;
  font-size: 26px;
  text-anchor: middle;
  font-family: var(--font-display);
}
.charges-plus text { fill: var(--amber); }
.charges-minus text { fill: var(--sky); }
.cap-layer.active .charges { opacity: 1; }
.cap-readout {
  margin: 0.6rem 0.2rem 0.4rem;
  font-size: 0.95rem;
  min-height: 3em;
  color: var(--ink);
}
.cap-readout strong { color: var(--amber); }

/* ---------- Interactivo: tormentas ---------- */
.storm-widget svg { width: 100%; height: auto; display: block; }
.storm-dot { fill: var(--amber-bright); opacity: 0; }
.storm-dot.flash { animation: stormFlash 0.9s ease-out; }
@keyframes stormFlash {
  0% { opacity: 0; }
  12% { opacity: 1; }
  100% { opacity: 0; }
}
.storm-panel {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1.2rem;
  padding: 0.8rem 0.3rem 0.2rem;
}
.storm-stat { display: flex; flex-direction: column; }
.stat-label { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.09em; color: var(--ink-soft); }
.stat-value {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.7rem;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}
.storm-note { padding: 0 0.3rem; }

/* ---------- Botones ---------- */
.btn {
  font: inherit;
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--ink);
  background: var(--paper-fig);
  border: 1.5px solid var(--line);
  border-radius: 999px;
  padding: 0.5rem 1.2rem;
  cursor: pointer;
  transition: border-color 0.2s, transform 0.12s, background 0.2s;
}
.btn:hover { border-color: var(--amber); }
.btn:active { transform: scale(0.97); }
.btn[aria-pressed="true"] {
  background: var(--amber);
  border-color: var(--amber);
  color: #241a08;
}
.btn-primary {
  background: var(--amber);
  border-color: var(--amber);
  color: #241a08;
}
.btn-primary:hover { background: var(--amber-bright); }

/* ---------- Interactivo: rayo ---------- */
#boltPath {
  opacity: 0;
}
#boltPath.strike {
  opacity: 1;
  stroke-dasharray: 260;
  stroke-dashoffset: 260;
  animation: boltDown 0.34s ease-in forwards, boltFade 0.7s ease-out 0.5s forwards;
}
@keyframes boltDown { to { stroke-dashoffset: 0; } }
@keyframes boltFade { to { opacity: 0; } }
#flowArrows .flow { opacity: 0; transition: opacity 0.4s ease 0.3s; }
#flowArrows.show .flow { opacity: 1; }
.cloud-charges text {
  font-weight: 900;
  font-size: 24px;
  text-anchor: middle;
  font-family: var(--font-display);
}
.cloud-charges.plus text { fill: var(--amber); }
.cloud-charges.minus text { fill: var(--sky); }
.lightning-controls {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  padding: 0.8rem 0.3rem 0.2rem;
}

/* ---------- Interactivo: onda ---------- */
.wave-widget svg { width: 100%; height: auto; display: block; }
#waveEndDot { transition: fill 0.3s; }
.wave-controls { padding: 0.6rem 0.3rem 0.3rem; }
.wave-controls label { font-weight: 700; font-size: 0.98rem; }
.wave-controls output { color: var(--amber); font-family: var(--font-display); font-weight: 900; font-size: 1.15rem; }
input[type="range"] {
  width: 100%;
  margin: 0.7rem 0 0.4rem;
  accent-color: var(--amber);
  height: 1.6rem;
}
.wave-verdict {
  margin: 0.2rem 0 0.4rem;
  font-size: 0.97rem;
  min-height: 3.2em;
}
.wave-verdict.fits strong { color: var(--ok); }
.wave-verdict.breaks strong { color: var(--warn); }

/* ---------- Interactivo: calculadora ---------- */
.calc-widget {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto auto;
  gap: 0.8rem 0.7rem;
  align-items: end;
  padding: 0.6rem 0.4rem 0.5rem;
}
.calc-row { display: flex; flex-direction: column; gap: 0.3rem; min-width: 0; }
.calc-row label { font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; color: var(--ink-soft); }
.calc-row .unit, .calc-result .unit { text-transform: none; letter-spacing: 0; font-weight: 400; }
.calc-widget input[type="number"] {
  font: inherit;
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  width: 100%;
  padding: 0.5rem 0.7rem;
  border: 1.5px solid var(--line);
  border-radius: 10px;
  background: var(--paper-fig);
  color: var(--ink);
}
.calc-widget input[type="number"]:focus-visible { outline: 3px solid var(--amber); outline-offset: 1px; }
.calc-op {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.6rem;
  color: var(--ink-soft);
  padding-bottom: 0.3rem;
}
.calc-result { display: flex; align-items: baseline; gap: 0.3rem; }
.calc-result output {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 2.3rem;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
  transition: color 0.3s;
}
.calc-result output.adjusted { color: var(--ok); }
.calc-widget .btn { grid-column: 1 / -1; justify-self: start; }
.calc-widget .fig-note { grid-column: 1 / -1; }
@media (max-width: 560px) {
  .calc-widget { grid-template-columns: 1fr auto; }
  .calc-op { display: none; }
  .calc-result { grid-column: 1 / -1; }
}

/* ---------- Panel 40.000 ---------- */
.chapter-panel {
  background: var(--paper-fig);
  border-block: 1px solid var(--line);
  max-width: none;
  padding-bottom: 3rem;
}
.chapter-panel .chapter-head,
.panel-intro, .panel-outro, .compare-grid {
  max-width: 1100px;
  margin-left: auto;
  margin-right: auto;
}
.chapter-panel .chapter-head { border-top: none; }
.panel-intro, .panel-outro { padding: 0 0 1.6rem; max-width: 760px; }
.panel-outro { padding-top: 1.8rem; }
.compare-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.4rem;
}
@media (max-width: 760px) { .compare-grid { grid-template-columns: 1fr; } }
.compare-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.3rem 1.4rem;
}
.compare-card h3 {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.25rem;
  margin-bottom: 0.8rem;
}
.card-esfera h3 { color: var(--sky); }
.card-domo h3 { color: var(--earth); }
.compare-card > svg { width: 100%; height: auto; display: block; margin-bottom: 0.6rem; }
.compare-card h3 svg { flex: none; }
.compare-math p { margin: 0 0 0.45rem; font-size: 0.97rem; }
.math-line {
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  background: var(--paper-fig);
  border: 1px dashed var(--line);
  border-radius: 8px;
  padding: 0.35rem 0.7rem;
  display: inline-block;
}
.verdict { font-style: italic; margin-top: 0.6rem !important; }
.verdict.ok { color: var(--ok); }
.verdict.warn { color: var(--warn); }

.panel-detail {
  max-width: 1100px;
  margin: 1.6rem auto 0;
  background: var(--card);
  border: 1px solid var(--line);
  border-left: 5px solid var(--amber);
  border-radius: 12px;
  box-shadow: var(--shadow);
  padding: 1.2rem 1.5rem 1.3rem;
}
.panel-detail h3 { font-size: 1.15rem; margin-bottom: 0.5rem; color: var(--amber); }
.panel-detail p { margin: 0; font-size: 1rem; }

/* ---------- Fórmulas ---------- */
.formula {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.15rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.8rem 1.1rem;
  flex-wrap: wrap;
}
.frac { display: inline-flex; flex-direction: column; text-align: center; }
.frac span:first-child { border-bottom: 2px solid var(--ink); padding: 0 0.4rem 0.15rem; }
.frac span:last-child { padding: 0.15rem 0.4rem 0; }
.eq { font-size: 1.4rem; }

/* ---------- En estudio ---------- */
.study-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.3rem;
  margin-top: 1.6rem;
}
@media (max-width: 900px) { .study-grid { grid-template-columns: 1fr; } }
.study-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.2rem 1.3rem;
}
.study-card h3 { font-size: 1.15rem; margin: 0.7rem 0 0.6rem; }
.study-card p { margin: 0; font-size: 0.97rem; }
.badge-study {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--warn);
  border: 1.5px solid currentColor;
  border-radius: 999px;
  padding: 0.22rem 0.7rem;
}
.badge-solid { color: var(--ok); }

/* ---------- Cierre ---------- */
.chapter-closing { padding-bottom: 3.5rem; }
.closing-body figure { margin: 0 0 1.4rem; }
.closing-body svg { width: 100%; max-width: 720px; height: auto; display: block; margin: 0 auto; }
.closing-body .prose { max-width: 720px; margin: 0 auto; }
.closing-line {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.3rem;
  line-height: 1.45;
  color: var(--sky);
  border-left: 4px solid var(--amber);
  padding-left: 1rem;
  margin-top: 1.4rem !important;
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--line);
  margin-top: 2rem;
}
.site-footer p {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.6rem 1.2rem 2.4rem;
  font-size: 0.85rem;
  color: var(--ink-soft);
}

/* ---------- Reveal on scroll ---------- */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  .model-stage .model-view, .path-inset .model-view { transition: none; }
  #modelSwitch .knob::after { transition: none; }
  .storm-dot.flash { animation: none; opacity: 0.85; }
  #boltPath.strike { animation: none; opacity: 1; stroke-dashoffset: 0; }
}