:root {
  color-scheme: dark;
  --bg: #040713;
  --bg-2: #080d21;
  --bg-3: #0d1732;
  --panel: rgba(12, 19, 44, 0.78);
  --panel-2: rgba(17, 28, 62, 0.9);
  --panel-3: rgba(4, 7, 19, 0.66);
  --line: rgba(160, 190, 255, 0.19);
  --line-strong: rgba(190, 220, 255, 0.34);
  --text: #f5f8ff;
  --muted: #aebae2;
  --muted-2: #7d8ab1;
  --accent: #78f3ff;
  --accent-2: #bb8cff;
  --accent-3: #ffe083;
  --accent-4: #8dffcb;
  --danger: #ff8aa3;
  --shadow: 0 26px 90px rgba(0, 0, 0, 0.5);
  --radius-xl: 34px;
  --radius-lg: 24px;
  --radius-md: 18px;
  --radius-sm: 12px;
  --max: 1200px;
  --header-h: 76px;
  --font-main: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-display: "Space Grotesk", Inter, ui-sans-serif, system-ui, sans-serif;
}

* {
  box-sizing: border-box;
}

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

body {
  min-height: 100vh;
  margin: 0;
  font-family: var(--font-main);
  line-height: 1.55;
  color: var(--text);
  background:
    radial-gradient(circle at 7% -5%, rgba(120, 243, 255, 0.16), transparent 32rem),
    radial-gradient(circle at 90% 4%, rgba(187, 140, 255, 0.19), transparent 30rem),
    radial-gradient(circle at 52% 106%, rgba(255, 224, 131, 0.10), transparent 32rem),
    linear-gradient(180deg, #050816 0%, #02030a 72%, #01020a 100%);
  overflow-x: hidden;
}

body::before,
body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: -2;
}

body::before {
  background-image:
    radial-gradient(circle, rgba(255,255,255,0.88) 0 1px, transparent 1.18px),
    radial-gradient(circle, rgba(120,243,255,0.62) 0 1px, transparent 1.22px),
    linear-gradient(rgba(255,255,255,0.028) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.026) 1px, transparent 1px);
  background-size: 72px 72px, 138px 138px, 92px 92px, 92px 92px;
  background-position: 0 0, 26px 39px, center top, center top;
  opacity: 0.28;
}

body::after {
  background: linear-gradient(112deg, transparent 8%, rgba(120, 243, 255, 0.06), transparent 44%);
  transform: translateX(-75%) skewX(-12deg);
  animation: sweep 18s linear infinite;
}

@keyframes sweep {
  from { transform: translateX(-75%) skewX(-12deg); }
  to { transform: translateX(75%) skewX(-12deg); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
  }
}

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

button, input, select {
  font: inherit;
}

button {
  cursor: pointer;
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

a {
  color: inherit;
}

code {
  padding: 0.12em 0.36em;
  border-radius: 0.5em;
  color: var(--accent);
  background: rgba(255,255,255,0.08);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  left: 1rem;
  top: 1rem;
  z-index: 1000;
  padding: 0.75rem 1rem;
  border-radius: 999px;
  color: #04101a;
  background: var(--accent);
  transform: translateY(-160%);
  transition: transform 160ms ease;
}

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

.page-shell {
  width: min(var(--max), calc(100% - 32px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 12px;
  z-index: 20;
  min-height: var(--header-h);
  margin: 12px 0 28px;
  padding: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background:
    linear-gradient(135deg, rgba(13, 23, 50, 0.96), rgba(5, 8, 22, 0.98)),
    #050816;
  box-shadow: 0 18px 70px rgba(0,0,0,0.28);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.8rem;
  padding: 0.25rem 0.8rem 0.25rem 0.25rem;
  text-decoration: none;
  min-width: 0;
}

.brand-orb {
  width: 44px;
  height: 44px;
  flex: 0 0 auto;
  border-radius: 50%;
  background:
    radial-gradient(circle at 32% 26%, #fffdf0 0 10%, #ffe083 22%, #ff8a43 54%, #521a23 100%);
  box-shadow: 0 0 28px rgba(255, 224, 131, 0.42), inset -10px -10px 20px rgba(0,0,0,0.24);
  position: relative;
}

.brand-orb::after {
  content: "";
  position: absolute;
  inset: -8px;
  border-radius: 50%;
  border: 1px solid rgba(255,224,131,0.28);
}

.brand-copy {
  display: grid;
  line-height: 1.1;
}

.brand-copy strong {
  font-family: var(--font-display);
  letter-spacing: -0.025em;
}

.brand-copy small {
  color: var(--muted-2);
  font-size: 0.78rem;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 0.28rem;
  padding-right: 0.3rem;
}

.site-nav a {
  padding: 0.7rem 0.8rem;
  border-radius: 999px;
  text-decoration: none;
  color: var(--muted);
  font-size: 0.92rem;
  transition: background 160ms ease, color 160ms ease, transform 160ms ease;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--text);
  background: rgba(255,255,255,0.08);
  transform: translateY(-1px);
}

.nav-toggle {
  display: none;
  width: 46px;
  height: 46px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255,255,255,0.06);
  color: var(--text);
}

.nav-toggle span:not(.sr-only) {
  display: block;
  width: 18px;
  height: 2px;
  margin: 4px auto;
  background: currentColor;
  border-radius: 99px;
}

main {
  display: grid;
  gap: 28px;
}

.section-frame,
.section-block {
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  background:
    linear-gradient(180deg, rgba(255,255,255,0.055), rgba(255,255,255,0.025)),
    rgba(8, 13, 33, 0.68);
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}

.section-block {
  padding: clamp(1.2rem, 3vw, 2.1rem);
}

.section-frame::before,
.section-block::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  pointer-events: none;
  background:
    radial-gradient(circle at 18% 0%, rgba(120, 243, 255, 0.10), transparent 28rem),
    radial-gradient(circle at 92% 14%, rgba(187, 140, 255, 0.10), transparent 26rem);
}

.section-frame > *,
.section-block > * {
  position: relative;
}

.hero {
  min-height: calc(100vh - 130px);
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.72fr);
  align-items: stretch;
  gap: clamp(1rem, 4vw, 2rem);
  padding: clamp(1.25rem, 4vw, 3rem);
}

.hero-copy {
  align-self: center;
  max-width: 780px;
}

.eyebrow,
.kicker {
  margin: 0 0 0.8rem;
  color: var(--accent);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-weight: 800;
}

h1, h2, h3 {
  font-family: var(--font-display);
  line-height: 1.02;
  letter-spacing: -0.055em;
  margin: 0;
}

h1 {
  font-size: clamp(3rem, 8vw, 6.9rem);
  max-width: 10ch;
}

h2 {
  font-size: clamp(2rem, 4vw, 3.45rem);
}

h3 {
  font-size: clamp(1.3rem, 2vw, 1.75rem);
}

p {
  color: var(--muted);
}

.hero-intro {
  max-width: 66ch;
  margin: 1.4rem 0 0;
  color: #ced7f7;
  font-size: clamp(1.04rem, 1.7vw, 1.25rem);
}

.hero-actions,
.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 1.45rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 46px;
  padding: 0.74rem 1rem;
  border: 1px solid transparent;
  border-radius: 999px;
  font-weight: 800;
  text-decoration: none;
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease, box-shadow 160ms ease;
}

.button:hover,
.button:focus-visible {
  transform: translateY(-2px);
}

.button-primary {
  color: #041018;
  background: linear-gradient(135deg, var(--accent), #dffcff);
  box-shadow: 0 16px 40px rgba(120, 243, 255, 0.18);
}

.button-ghost,
.button-secondary {
  color: var(--text);
  border-color: var(--line-strong);
  background: rgba(255,255,255,0.055);
}

.button-secondary {
  min-height: 42px;
  padding: 0.62rem 0.9rem;
  font-size: 0.92rem;
}

.metric-strip {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.7rem;
  max-width: 760px;
  margin: 2rem 0 0;
}

.metric-strip div,
.brief-card,
.lesson-card,
.source-grid article,
.scale-card,
.quiz-card,
.control-panel,
.canvas-card,
.dwarf-card,
.compare-metric,
.timeline li,
.details-grid details {
  border: 1px solid var(--line);
  background: rgba(255,255,255,0.045);
  border-radius: var(--radius-lg);
}

.metric-strip div {
  padding: 1rem;
}

.metric-strip dt {
  color: var(--muted-2);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 800;
}

.metric-strip dd {
  margin: 0.25rem 0 0;
  font-size: clamp(1.4rem, 2vw, 2rem);
  font-family: var(--font-display);
  font-weight: 900;
}

.hero-console {
  padding: clamp(1rem, 3vw, 1.4rem);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-xl);
  background:
    linear-gradient(180deg, rgba(255,255,255,0.08), rgba(255,255,255,0.03)),
    rgba(8, 13, 33, 0.84);
  display: grid;
  align-content: start;
  gap: 1rem;
  overflow: hidden;
}

.console-topline {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  color: var(--accent-4);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.75rem;
  font-weight: 900;
}

.status-dot {
  width: 0.65rem;
  height: 0.65rem;
  border-radius: 50%;
  background: var(--accent-4);
  box-shadow: 0 0 18px rgba(141, 255, 203, 0.68);
}

.css-orbit-model {
  min-height: 320px;
  border-radius: var(--radius-lg);
  background:
    radial-gradient(circle at center, rgba(255,224,131,0.18), transparent 16%),
    radial-gradient(circle at 50% 48%, rgba(120,243,255,0.05), transparent 62%),
    rgba(0,0,0,0.22);
  position: relative;
  overflow: hidden;
}

.css-orbit-model .sun,
.css-orbit-model .orbit,
.css-orbit-model .orbit i {
  position: absolute;
  border-radius: 50%;
}

.css-orbit-model .sun {
  width: 74px;
  height: 74px;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  background: radial-gradient(circle at 30% 25%, #fffdf0 0 10%, #ffe083 26%, #ff8f42 62%, #4a1622 100%);
  box-shadow: 0 0 52px rgba(255,224,131,0.62);
}

.css-orbit-model .orbit {
  inset: var(--inset);
  border: 1px solid rgba(160,190,255,0.18);
  animation: rotate var(--duration) linear infinite;
}

.css-orbit-model .orbit i {
  width: var(--planet);
  height: var(--planet);
  top: calc(50% - var(--planet) / 2);
  left: calc(-1 * var(--planet) / 2);
  background: var(--colour);
  box-shadow: 0 0 24px var(--glow);
}

.orbit-1 { --inset: 42px; --duration: 14s; --planet: 11px; --colour: #c8b8a2; --glow: rgba(200,184,162,.6); }
.orbit-2 { --inset: 72px; --duration: 22s; --planet: 18px; --colour: #e8ac62; --glow: rgba(232,172,98,.6); }
.orbit-3 { --inset: 108px; --duration: 30s; --planet: 20px; --colour: #55b8ff; --glow: rgba(85,184,255,.6); }
.orbit-4 { --inset: 146px; --duration: 42s; --planet: 15px; --colour: #d46e44; --glow: rgba(212,110,68,.6); }

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

.check-list {
  display: grid;
  gap: 0.65rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.check-list li {
  color: #d7def7;
  position: relative;
  padding-left: 1.7rem;
}

.check-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--accent-4);
  font-weight: 900;
}

.section-heading {
  display: grid;
  gap: 0.65rem;
  margin-bottom: 1.45rem;
}

.section-heading p:not(.eyebrow) {
  max-width: 76ch;
  margin: 0;
}

.section-heading--split {
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: end;
  gap: 1rem;
}

.note-chip {
  justify-self: start;
  padding: 0.62rem 0.9rem;
  border: 1px solid rgba(255,224,131,0.32);
  border-radius: 999px;
  color: #ffe8a8;
  background: rgba(255,224,131,0.08);
  font-weight: 800;
}

.brief-grid,
.lesson-grid,
.source-grid,
.scale-grid,
.dwarf-grid,
.details-grid {
  display: grid;
  gap: 1rem;
}

.brief-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.brief-card,
.source-grid article,
.dwarf-card,
.details-grid details {
  padding: 1.1rem;
}

.brief-card span {
  display: inline-grid;
  place-items: center;
  width: 2.2rem;
  height: 2.2rem;
  border: 1px solid var(--line);
  border-radius: 50%;
  color: var(--accent);
  font-weight: 900;
  margin-bottom: 0.9rem;
}

.brief-card p,
.source-grid p,
.dwarf-card p,
.timeline p,
.details-grid p {
  margin-bottom: 0;
}

.lab-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(315px, 0.38fr);
  gap: 1rem;
  align-items: stretch;
}

.canvas-card {
  min-height: 560px;
  padding: 0.75rem;
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(circle at center, rgba(120, 243, 255, 0.07), transparent 45%),
    rgba(0,0,0,0.2);
}

#orbitCanvas {
  display: block;
  width: 100%;
  height: 100%;
  min-height: 530px;
  border-radius: calc(var(--radius-lg) - 8px);
}

.canvas-hint {
  position: absolute;
  left: 1.1rem;
  bottom: 1.1rem;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  background: rgba(3, 5, 13, 0.92);
  font-size: 0.85rem;
}

.control-panel {
  padding: 1.1rem;
  background:
    linear-gradient(180deg, rgba(255,255,255,0.07), rgba(255,255,255,0.03)),
    rgba(4,7,19,0.48);
}

.selected-object p {
  margin: 0.65rem 0 0;
}

.selected-planet-art {
  width: 128px;
  height: 128px;
  border-radius: 50%;
  margin: 1.15rem auto;
  background: radial-gradient(circle at 32% 24%, #fff 0 6%, #58b8ff 28%, #173a85 78%, #081838 100%);
  box-shadow: 0 0 45px rgba(90, 189, 255, 0.34), inset -18px -20px 34px rgba(0,0,0,0.24);
  position: relative;
}

.selected-planet-art.has-rings::before {
  content: "";
  position: absolute;
  left: -42px;
  right: -42px;
  top: 50%;
  height: 24px;
  transform: translateY(-50%) rotate(-15deg);
  border: 4px solid rgba(255,224,131,0.65);
  border-left-color: rgba(255,224,131,0.16);
  border-right-color: rgba(255,224,131,0.16);
  border-radius: 50%;
  z-index: -1;
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.6rem;
  margin: 1rem 0;
}

.stat {
  padding: 0.75rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: rgba(255,255,255,0.04);
}

.stat span {
  display: block;
  color: var(--muted-2);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 800;
}

.stat strong {
  display: block;
  margin-top: 0.24rem;
  font-family: var(--font-display);
  font-size: 1.1rem;
}

.control-group {
  display: grid;
  gap: 0.45rem;
  margin-top: 1rem;
}

label span,
.control-group label,
.scale-control label {
  color: var(--muted-2);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 900;
}

input,
select {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  color: var(--text);
  background: rgba(5,8,22,0.78);
  padding: 0.65rem 0.75rem;
  outline: none;
}

input[type="range"] {
  accent-color: var(--accent);
  padding: 0;
}

input:focus,
select:focus,
button:focus-visible,
a:focus-visible,
details:focus-within {
  outline: 3px solid rgba(120, 243, 255, 0.34);
  outline-offset: 2px;
}

.microcopy {
  margin: 0;
  color: var(--muted-2);
  font-size: 0.86rem;
}

.toolbox,
.compare-selectors {
  display: grid;
  grid-template-columns: repeat(3, minmax(160px, 1fr));
  gap: 0.75rem;
  min-width: min(640px, 100%);
}

.compare-selectors {
  grid-template-columns: repeat(2, minmax(160px, 1fr));
  min-width: min(430px, 100%);
}

.toolbox label,
.compare-selectors label {
  display: grid;
  gap: 0.35rem;
}

.planet-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem;
}

.planet-card {
  position: relative;
  min-height: 310px;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  color: var(--text);
  background: rgba(255,255,255,0.045);
  text-align: left;
  overflow: hidden;
  transition: transform 180ms ease, border-color 180ms ease, background 180ms ease, box-shadow 180ms ease;
}

.planet-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 18%, var(--planet-glow, rgba(120,243,255,0.12)), transparent 40%);
  opacity: 0.85;
  pointer-events: none;
}

.planet-card:hover,
.planet-card:focus-visible,
.planet-card.is-selected {
  transform: translateY(-4px);
  border-color: rgba(120, 243, 255, 0.56);
  background: rgba(255,255,255,0.07);
  box-shadow: 0 24px 70px rgba(0,0,0,0.28);
}

.planet-card > * {
  position: relative;
}

.planet-visual {
  display: block;
  width: 105px;
  height: 105px;
  border-radius: 50%;
  margin: 0 auto 1rem;
  background: var(--planet-gradient);
  box-shadow: 0 0 42px var(--planet-glow), inset -16px -18px 28px rgba(0,0,0,0.28);
}

.planet-visual.has-rings {
  position: relative;
}

.planet-visual.has-rings::after {
  content: "";
  position: absolute;
  left: -30px;
  right: -30px;
  top: 50%;
  height: 18px;
  transform: translateY(-50%) rotate(-15deg);
  border: 3px solid rgba(255,224,131,0.62);
  border-left-color: rgba(255,224,131,0.16);
  border-right-color: rgba(255,224,131,0.16);
  border-radius: 50%;
}

.planet-card h3 {
  margin-bottom: 0.2rem;
}

.planet-card .family-tag {
  display: inline-flex;
  margin-bottom: 0.65rem;
  padding: 0.25rem 0.5rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--accent);
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 900;
}

.card-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.5rem;
  margin-top: 0.85rem;
}

.card-facts span {
  padding: 0.48rem;
  border-radius: var(--radius-sm);
  background: rgba(0,0,0,0.18);
  color: var(--muted);
  font-size: 0.82rem;
}

.compare-grid {
  display: grid;
  gap: 0.7rem;
}

.compare-metric {
  padding: 1rem;
  display: grid;
  grid-template-columns: 190px 1fr;
  gap: 1rem;
  align-items: center;
}

.compare-label strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.1rem;
}

.compare-label span {
  color: var(--muted-2);
  font-size: 0.86rem;
}

.compare-bars {
  display: grid;
  gap: 0.55rem;
}

.compare-bar-row {
  display: grid;
  grid-template-columns: 96px 1fr 118px;
  gap: 0.65rem;
  align-items: center;
  color: var(--muted);
  font-size: 0.9rem;
}

.bar-track {
  height: 14px;
  border-radius: 999px;
  background: rgba(255,255,255,0.08);
  overflow: hidden;
}

.bar-fill {
  display: block;
  width: var(--bar-width, 20%);
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
}

.scale-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-bottom: 1rem;
}

.scale-control {
  display: grid;
  gap: 0.45rem;
  min-width: min(360px, 100%);
}

.range-row {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 0.8rem;
}

output {
  min-width: 72px;
  text-align: center;
  color: var(--accent);
  font-weight: 900;
}

.scale-card {
  padding: 1.15rem;
}

.scale-card strong {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2.4rem);
  letter-spacing: -0.05em;
}

.scale-card--sun {
  background:
    radial-gradient(circle at 92% 20%, rgba(255,224,131,0.17), transparent 42%),
    rgba(255,255,255,0.045);
}

.table-wrap {
  overflow: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 760px;
  background: rgba(0,0,0,0.14);
}

.data-table caption {
  text-align: left;
  padding: 0.9rem 1rem;
  color: var(--muted);
  font-weight: 800;
}

.data-table th,
.data-table td {
  padding: 0.85rem 1rem;
  border-top: 1px solid rgba(160,190,255,0.12);
  text-align: left;
}

.data-table th {
  color: var(--accent);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

.dwarf-grid {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.dwarf-card {
  min-height: 260px;
  overflow: hidden;
  position: relative;
}

.dwarf-card::before {
  content: "";
  position: absolute;
  width: 140px;
  height: 140px;
  right: -55px;
  top: -45px;
  border-radius: 50%;
  background: var(--dwarf-gradient);
  box-shadow: 0 0 48px var(--dwarf-glow);
  opacity: 0.65;
}

.dwarf-card > * {
  position: relative;
}

.dwarf-card small {
  display: inline-flex;
  margin-bottom: 0.7rem;
  color: var(--accent-3);
  font-weight: 900;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.timeline li {
  padding: 1.15rem;
}

.timeline span {
  display: inline-flex;
  margin-bottom: 0.7rem;
  color: var(--accent);
  font-weight: 900;
}

.quiz-card {
  padding: clamp(1rem, 3vw, 1.4rem);
  background:
    radial-gradient(circle at 95% 0%, rgba(187,140,255,0.13), transparent 38%),
    rgba(255,255,255,0.045);
}

.quiz-progress {
  color: var(--accent);
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.78rem;
}

.quiz-question {
  margin: 0.7rem 0 1rem;
  font-family: var(--font-display);
  color: var(--text);
  font-size: clamp(1.45rem, 2.6vw, 2.1rem);
  line-height: 1.12;
}

.quiz-options {
  display: grid;
  gap: 0.7rem;
}

.quiz-option {
  width: 100%;
  padding: 0.9rem 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  color: var(--text);
  background: rgba(0,0,0,0.18);
  text-align: left;
  transition: border-color 160ms ease, transform 160ms ease, background 160ms ease;
}

.quiz-option:hover,
.quiz-option:focus-visible {
  border-color: rgba(120,243,255,0.48);
  transform: translateY(-1px);
}

.quiz-option.is-correct {
  border-color: rgba(141,255,203,0.7);
  background: rgba(141,255,203,0.12);
}

.quiz-option.is-wrong {
  border-color: rgba(255,138,163,0.72);
  background: rgba(255,138,163,0.12);
}

.quiz-feedback {
  margin: 1rem 0 0;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-md);
  background: rgba(255,255,255,0.06);
}

.quiz-actions {
  margin-top: 1rem;
}

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

.details-grid details {
  background: rgba(255,255,255,0.045);
}

.details-grid summary {
  cursor: pointer;
  color: var(--text);
  font-weight: 900;
}

.source-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.source-grid a {
  display: inline-flex;
  margin-top: 0.6rem;
  color: var(--accent);
  overflow-wrap: anywhere;
}

.site-footer {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 1.2fr);
  gap: 1rem;
  padding: 2rem 0 3rem;
  color: var(--muted-2);
}

.site-footer div {
  display: grid;
  gap: 0.3rem;
}

.site-footer strong {
  color: var(--text);
  font-family: var(--font-display);
}

.site-footer p {
  margin: 0;
}

.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.75rem 1rem;
}

.site-footer a {
  color: var(--accent);
}

.footer-legal {
  color: var(--muted);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.empty-state {
  grid-column: 1 / -1;
  padding: 1.2rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: rgba(255,255,255,0.04);
}

@media (max-width: 1060px) {
  .hero,
  .lab-layout,
  .section-heading--split {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  h1 {
    max-width: 12ch;
  }

  .metric-strip,
  .brief-grid,
  .planet-grid,
  .source-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (max-width: 820px) {
  .page-shell {
    width: min(100% - 20px, var(--max));
  }

  .site-header {
    border-radius: 24px;
    align-items: start;
    flex-wrap: wrap;
  }

  .nav-toggle {
    display: inline-block;
    margin-left: auto;
  }

  .site-nav {
    display: none;
    width: 100%;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.35rem;
    padding: 0.4rem 0 0;
  }

  .site-nav.is-open {
    display: grid;
  }

  .site-nav a {
    background: rgba(255,255,255,0.045);
    text-align: center;
  }

  .metric-strip,
  .brief-grid,
  .planet-grid,
  .scale-grid,
  .dwarf-grid,
  .timeline,
  .details-grid,
  .source-grid,
  .site-footer {
    grid-template-columns: 1fr;
  }

  .site-footer nav {
    justify-content: flex-start;
  }

  .toolbox,
  .compare-selectors {
    grid-template-columns: 1fr;
    min-width: 0;
  }

  .canvas-card {
    min-height: 430px;
  }

  #orbitCanvas {
    min-height: 400px;
  }

  .compare-metric {
    grid-template-columns: 1fr;
  }

  .compare-bar-row {
    grid-template-columns: 76px 1fr 88px;
    gap: 0.45rem;
  }
}

@media (max-width: 520px) {
  .brand-copy small {
    display: none;
  }

  .hero,
  .section-block {
    border-radius: 24px;
    padding: 1rem;
  }

  h1 {
    font-size: clamp(2.7rem, 14vw, 4rem);
  }

  .hero-actions,
  .button-row {
    flex-direction: column;
  }

  .button {
    width: 100%;
  }

  .stat-grid,
  .card-facts {
    grid-template-columns: 1fr;
  }

  .css-orbit-model {
    min-height: 260px;
  }
}