:root {
  color-scheme: light;
  --ink: #f1f4f3;
  --surface: #ffffff;
  --surface-raised: #e9eeec;
  --line: rgba(18, 31, 38, 0.12);
  --line-strong: rgba(18, 31, 38, 0.25);
  --paper: #111c22;
  --muted: #637078;
  --danger: #a63f36;
  --accent: #315f78;
  --accent-strong: #23495f;
  --accent-soft: rgba(49, 95, 120, 0.11);
  --accent-contrast: #ffffff;
  --sans: "Manrope", system-ui, sans-serif;
  --serif: "Newsreader", Georgia, serif;
  --mono: "DM Mono", ui-monospace, monospace;
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
  overflow-x: hidden;
  color: var(--paper);
  background:
    radial-gradient(circle at 78% 18%, color-mix(in srgb, var(--accent) 9%, transparent), transparent 28rem),
    linear-gradient(rgba(18, 31, 38, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(18, 31, 38, 0.035) 1px, transparent 1px),
    var(--ink);
  background-size: auto, 72px 72px, 72px 72px, auto;
  font-family: var(--sans);
  transition: background 400ms ease;
}

button,
input {
  font: inherit;
}

button {
  color: inherit;
}

button:focus-visible,
input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

#atlas-canvas {
  display: none;
}

.topbar,
main,
.keyboard-hint {
  position: relative;
  z-index: 1;
}

.topbar {
  height: 72px;
  padding: 0 4vw;
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: rgba(248, 250, 249, 0.86);
  backdrop-filter: blur(18px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0;
  border: 0;
  background: none;
  font: 500 0.76rem/1 var(--mono);
  letter-spacing: 0.13em;
  cursor: pointer;
}

.brand b {
  color: var(--muted);
  font-weight: 400;
}

.brand-icon { display: block; width: 30px; height: 30px; border-radius: 7px; }

.hanging-motif {
  position: fixed;
  z-index: 3;
  top: 71px;
  right: 7vw;
  width: 92px;
  height: 96px;
  pointer-events: none;
  color: var(--accent);
  opacity: .72;
  transition: color 280ms ease, transform 500ms cubic-bezier(.2,.8,.2,1);
}

.motif-line {
  position: absolute;
  top: 0;
  right: 26px;
  width: 1px;
  height: 58px;
  background: currentColor;
}

.motif-node {
  position: absolute;
  border: 1px solid currentColor;
  border-radius: 50%;
  background: var(--ink);
}

.node-a { top: 22px; right: 20px; width: 13px; height: 13px; }
.node-b { top: 51px; right: 23px; width: 7px; height: 7px; background: currentColor; }
.motif-glyph { position: absolute; right: 0; bottom: 0; width: 54px; height: 35px; border-top: 1px solid currentColor; }
.motif-glyph::before,
.motif-glyph::after { content: ""; position: absolute; inset: 7px 24px; border-left: 1px solid currentColor; transform: rotate(36deg); }
.motif-glyph::after { transform: rotate(-36deg); }

.topbar-meta {
  display: flex;
  align-items: center;
  gap: 18px;
  color: var(--muted);
  font: 400 0.68rem/1 var(--mono);
  letter-spacing: 0.08em;
}

.topbar-rule { width: 54px; height: 1px; background: var(--line-strong); }

.icon-button {
  width: 36px;
  height: 36px;
  border: 1px solid var(--line);
  background: transparent;
  display: grid;
  place-items: center;
  cursor: pointer;
}

.icon-button:hover { border-color: var(--accent); color: var(--accent); }
.icon-button svg { width: 16px; fill: none; stroke: currentColor; stroke-width: 1.5; }

.screen {
  width: min(1440px, 100%);
  min-height: calc(100vh - 72px);
  margin: 0 auto;
  display: none;
}

.screen.is-active { display: block; animation: reveal 480ms cubic-bezier(.2,.75,.25,1); }

@keyframes reveal {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}

.atlas-screen { padding: clamp(32px, 5vw, 76px) 4vw 56px; }

.atlas-intro {
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(280px, 0.55fr);
  align-items: end;
  gap: 8vw;
  margin-bottom: clamp(38px, 6vw, 74px);
}

.eyebrow,
.source-line,
.section-heading,
.stage-meta,
.route-footer,
.chart-header {
  margin: 0;
  font: 500 0.67rem/1.4 var(--mono);
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--accent);
}

h1 {
  max-width: 840px;
  margin: 18px 0 0;
  font-size: clamp(3.2rem, 6.9vw, 7.15rem);
  line-height: 0.87;
  letter-spacing: -0.062em;
  font-weight: 500;
}

h1 em {
  color: var(--accent);
  font-family: var(--serif);
  font-weight: 400;
}

.intro-copy {
  max-width: 440px;
  margin: 0 0 7px;
  color: #4f5e66;
  font-size: 0.98rem;
  line-height: 1.75;
}

.discipline-tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  margin-bottom: 42px;
}

.discipline-tab {
  position: relative;
  min-height: 86px;
  padding: 18px 26px;
  border: 0;
  background: transparent;
  display: flex;
  align-items: center;
  gap: 20px;
  text-align: left;
  cursor: pointer;
}

.discipline-tab + .discipline-tab { border-left: 1px solid var(--line); }
.discipline-tab::after { content: ""; position: absolute; inset: auto 0 -1px; height: 2px; background: var(--accent); transform: scaleX(0); transition: transform 220ms ease; }
.discipline-tab.active { background: var(--accent-soft); }
.discipline-tab.active::after { transform: scaleX(1); }
.tab-index { color: var(--accent); font: 400 1.1rem var(--serif); }
.discipline-tab strong { display: block; margin-bottom: 4px; font-size: 0.96rem; font-weight: 600; }
.discipline-tab small { color: var(--muted); font-size: 0.76rem; }

.path-layout {
  display: grid;
  grid-template-columns: minmax(420px, 0.92fr) minmax(430px, 1.08fr);
  gap: clamp(30px, 5vw, 76px);
}

.section-heading {
  display: flex;
  justify-content: space-between;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
}

.path-button {
  position: relative;
  width: 100%;
  min-height: 120px;
  padding: 22px 48px 22px 20px;
  border: 0;
  border-bottom: 1px solid var(--line);
  background: transparent;
  display: grid;
  grid-template-columns: 60px minmax(0, 1fr) auto;
  align-items: center;
  gap: 10px;
  text-align: left;
  cursor: pointer;
  transition: background 180ms ease, padding 180ms ease;
}

.path-button:hover,
.path-button.selected { background: var(--path-soft); padding-left: 26px; }
.path-number { color: var(--muted); font: 400 0.68rem var(--mono); }
.path-copy strong { display: block; margin-bottom: 7px; font-size: 1.15rem; font-weight: 500; }
.path-copy small { color: var(--muted); font-size: 0.78rem; line-height: 1.45; }
.path-status { font: 400 0.64rem var(--mono); color: var(--path-accent); letter-spacing: .08em; }
.path-arrow { position: absolute; right: 20px; top: 50%; transform: translateY(-50%); color: var(--accent); opacity: 0; transition: opacity 180ms ease; }
.path-button:hover .path-arrow,
.path-button.selected .path-arrow { opacity: 1; color: var(--path-accent); }

.path-button::before {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  bottom: 18px;
  width: 2px;
  background: var(--path-accent);
  transform: scaleY(0);
  transition: transform 180ms ease;
}

.path-button:hover::before,
.path-button.selected::before { transform: scaleY(1); }

.chart-frame {
  position: sticky;
  top: 96px;
  min-height: 512px;
  overflow: hidden;
  border: 1px solid var(--line-strong);
  background: linear-gradient(145deg, var(--accent-soft), rgba(255, 255, 255, 0.92) 54%);
  box-shadow: 0 24px 70px rgba(22, 38, 46, 0.08);
  isolation: isolate;
}

.chart-frame::before,
.chart-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(to bottom, black, transparent 74%);
  z-index: -2;
}

.chart-frame::after { background-size: 8px 8px; opacity: .18; }
.chart-header { position: absolute; inset: 20px 22px auto; display: flex; justify-content: space-between; color: var(--muted); }
.chart-symbol { position: absolute; width: 190px; height: 190px; left: 50%; top: 42%; transform: translate(-50%, -50%); }

.chart-symbol::before,
.chart-symbol::after {
  content: "";
  position: absolute;
  inset: 12px 78px;
  border: 1px solid var(--accent);
  transform: rotate(35deg);
  box-shadow: 0 0 26px color-mix(in srgb, var(--accent) 34%, transparent);
}

.chart-symbol::after { transform: rotate(-35deg); }
.chart-symbol > span { position: absolute; display: block; color: var(--accent); transition: all 360ms ease; }
.chart-orbit { position: absolute; left: 50%; top: 42%; border: 1px solid var(--line-strong); border-radius: 50%; transform: translate(-50%, -50%) rotate(-12deg); }
.orbit-one { width: 280px; height: 138px; }
.orbit-two { width: 370px; height: 214px; transform: translate(-50%, -50%) rotate(18deg); }
.chart-center { position: absolute; left: 50%; top: 42%; width: 8px; height: 8px; background: var(--paper); border-radius: 50%; box-shadow: 0 0 22px var(--accent); transform: translate(-50%, -50%); }
.chart-coordinates { position: absolute; right: 22px; top: 34%; color: var(--muted); font: 400 .6rem/1.8 var(--mono); text-align: right; }

/* Each lineage keeps the same cartographic system but speaks in a different geometry. */
body[data-path-theme="norse"] .chart-frame::after {
  background-image: repeating-linear-gradient(35deg, transparent 0 18px, color-mix(in srgb, var(--accent) 13%, transparent) 18px 19px);
  background-size: auto;
  opacity: .48;
}
body[data-path-theme="norse"] .symbol-a { left: 50%; top: 10px; width: 1px; height: 170px; background: var(--accent); transform: rotate(90deg); }
body[data-path-theme="norse"] .motif-glyph { transform: skewX(-18deg); }

body[data-path-theme="turkic"] .chart-frame::after {
  background-image: radial-gradient(circle, color-mix(in srgb, var(--accent) 24%, transparent) 1px, transparent 1.2px);
  background-size: 18px 18px;
  opacity: .45;
}
body[data-path-theme="turkic"] .chart-symbol::before,
body[data-path-theme="turkic"] .chart-symbol::after { inset: 18px; border-radius: 50%; transform: none; box-shadow: none; }
body[data-path-theme="turkic"] .chart-symbol::after { inset: 53px; }
body[data-path-theme="turkic"] .symbol-a { left: 50%; top: -15px; width: 1px; height: 220px; background: var(--accent); }
body[data-path-theme="turkic"] .symbol-b { left: 34px; right: 34px; top: 50%; height: 1px; background: var(--accent); }
body[data-path-theme="turkic"] .motif-glyph { width: 38px; height: 38px; border: 1px solid currentColor; border-radius: 50%; }

body[data-path-theme="greek"] .chart-frame::after {
  background-image: linear-gradient(90deg, color-mix(in srgb, var(--accent) 12%, transparent) 1px, transparent 1px), linear-gradient(color-mix(in srgb, var(--accent) 12%, transparent) 1px, transparent 1px);
  background-size: 72px 24px;
  opacity: .52;
}
body[data-path-theme="greek"] .chart-symbol::before,
body[data-path-theme="greek"] .chart-symbol::after { inset: 36px 51px; border: 0; border-left: 11px double var(--accent); border-right: 11px double var(--accent); transform: none; box-shadow: none; }
body[data-path-theme="greek"] .chart-symbol::after { inset: 18px 36px 142px; border: 0; border-top: 3px double var(--accent); }
body[data-path-theme="greek"] .symbol-a { left: 34px; right: 34px; bottom: 17px; height: 7px; border-top: 1px solid var(--accent); border-bottom: 3px double var(--accent); }
body[data-path-theme="greek"] .motif-glyph { border: 0; border-top: 3px double currentColor; border-bottom: 1px solid currentColor; }
body[data-path-theme="greek"] .motif-glyph::before,
body[data-path-theme="greek"] .motif-glyph::after { transform: none; inset: 4px 14px; border-left: 3px double currentColor; }
body[data-path-theme="greek"] .motif-glyph::after { inset-inline: 36px 4px; }

body[data-path-theme="stoicism"] .chart-frame::after {
  background-image: repeating-radial-gradient(circle at 50% 42%, transparent 0 25px, color-mix(in srgb, var(--accent) 12%, transparent) 26px 27px);
  background-size: auto;
  opacity: .55;
}
body[data-path-theme="stoicism"] .chart-symbol::before,
body[data-path-theme="stoicism"] .chart-symbol::after { inset: 20px; border-radius: 50%; transform: none; box-shadow: none; }
body[data-path-theme="stoicism"] .chart-symbol::after { inset: 60px; }
body[data-path-theme="stoicism"] .symbol-a { left: 0; right: 0; top: 50%; height: 1px; background: var(--accent); }
body[data-path-theme="stoicism"] .symbol-b { left: 50%; top: 0; bottom: 0; width: 1px; background: var(--accent); }
body[data-path-theme="stoicism"] .motif-glyph { width: 40px; height: 40px; border: 1px solid currentColor; border-radius: 50%; }
body[data-path-theme="stoicism"] .motif-glyph::before { inset: 8px; border: 1px solid currentColor; border-radius: 50%; transform: none; }
body[data-path-theme="stoicism"] .motif-glyph::after { display: none; }

body[data-path-theme="existentialism"] .chart-frame::after {
  background-image: repeating-linear-gradient(90deg, transparent 0 45px, color-mix(in srgb, var(--accent) 12%, transparent) 45px 46px);
  background-size: auto;
  transform: skewX(-9deg);
  opacity: .52;
}
body[data-path-theme="existentialism"] .chart-symbol::before,
body[data-path-theme="existentialism"] .chart-symbol::after { inset: 29px; transform: rotate(8deg); box-shadow: none; }
body[data-path-theme="existentialism"] .chart-symbol::after { transform: translate(22px, -16px) rotate(-6deg); }
body[data-path-theme="existentialism"] .motif-glyph { transform: translateX(-8px) rotate(8deg); border: 1px solid currentColor; }

body[data-path-theme="platonism"] .chart-frame::after {
  background-image: linear-gradient(30deg, transparent 48%, color-mix(in srgb, var(--accent) 12%, transparent) 49% 51%, transparent 52%);
  background-size: 48px 84px;
  opacity: .5;
}
body[data-path-theme="platonism"] .chart-symbol::before { inset: 16px; border-radius: 50%; transform: none; box-shadow: none; }
body[data-path-theme="platonism"] .chart-symbol::after { inset: 48px; transform: rotate(45deg); box-shadow: none; }
body[data-path-theme="platonism"] .symbol-a { inset: 76px; border: 1px solid var(--accent); border-radius: 50%; }
body[data-path-theme="platonism"] .motif-glyph { width: 38px; height: 38px; border: 1px solid currentColor; transform: rotate(45deg); }
body[data-path-theme="platonism"] .motif-glyph::before { inset: 8px; border: 1px solid currentColor; border-radius: 50%; transform: none; }
body[data-path-theme="platonism"] .motif-glyph::after { display: none; }

body[data-path-theme="turkic"] .route-nodes::before { background: repeating-linear-gradient(to bottom, var(--accent) 0 5px, transparent 5px 10px); }
body[data-path-theme="greek"] .route-nodes::before { width: 3px; background: linear-gradient(90deg, var(--accent) 0 1px, transparent 1px 2px, var(--accent) 2px 3px); }
body[data-path-theme="stoicism"] .route-nodes::before { background: repeating-linear-gradient(to bottom, var(--accent) 0 2px, transparent 2px 7px); }
body[data-path-theme="existentialism"] .route-nodes::before { left: 17px; background: repeating-linear-gradient(to bottom, var(--accent) 0 11px, transparent 11px 16px); }
body[data-path-theme="platonism"] .route-nodes::before { background: linear-gradient(to bottom, var(--accent), transparent 76%, var(--accent)); }

.chart-caption {
  position: absolute;
  inset: auto 0 0;
  padding: 28px 30px;
  background: linear-gradient(to top, rgba(255,255,255,.98) 68%, transparent);
}

.chart-caption h2 { max-width: 520px; margin: 8px 0; font-size: clamp(1.55rem, 2.5vw, 2.55rem); line-height: 1.08; font-weight: 500; letter-spacing: -.035em; }
.chart-caption > p:not(.eyebrow) { max-width: 470px; margin: 0 0 24px; color: var(--muted); font-size: .84rem; line-height: 1.6; }

.primary-action,
.submit-answer,
.feedback-panel button,
.dialog-actions button {
  min-height: 46px;
  padding: 0 18px;
  border: 1px solid var(--accent);
  background: var(--accent);
  color: var(--accent-contrast);
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  font: 500 .69rem var(--mono);
  letter-spacing: .1em;
  cursor: pointer;
  transition: filter 180ms ease, transform 180ms ease;
}

.primary-action:hover,
.submit-answer:not(:disabled):hover,
.feedback-panel button:hover,
.dialog-actions button:hover { filter: brightness(1.12); transform: translateY(-1px); }

.lesson-screen.is-active { display: grid; grid-template-columns: 260px minmax(440px, 1fr) 280px; }
/* Course map: the selected path's lessons as stops on a winding route. */
.course-map { margin-top: clamp(40px, 6vw, 72px); }
.course-map .section-heading { flex-wrap: wrap; gap: 6px 18px; }
.course-map[hidden] { display: none; }
.course-route {
  position: relative;
  display: grid;
  grid-template-columns: repeat(var(--stops, 4), minmax(0, 1fr));
  margin: 0;
  padding: 0;
  list-style: none;
}
.course-route::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 112px;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(to right, transparent, black 10%, black 90%, transparent);
  pointer-events: none;
}
.course-line { position: absolute; inset: 0 0 auto; width: 100%; height: 112px; overflow: visible; pointer-events: none; }
.course-line path { fill: none; vector-effect: non-scaling-stroke; }
.course-line-base { stroke: var(--line-strong); stroke-width: 1.5; stroke-dasharray: 5 6; }
.course-line-charted { stroke: var(--accent); stroke-width: 2; }
.course-stop { position: relative; }
.course-stop button {
  width: 100%;
  height: 100%;
  padding: 128px 18px 24px;
  border: 0;
  background: transparent;
  color: inherit;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 7px;
  font: inherit;
  text-align: center;
  cursor: pointer;
  transition: background 180ms ease;
}
.course-stop button:hover,
.course-stop button:focus-visible { background: var(--accent-soft); }
.stop-marker {
  position: absolute;
  left: 50%;
  top: var(--y);
  width: 15px;
  height: 15px;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  background: #fff;
  transform: translate(-50%, -50%);
  transition: box-shadow 180ms ease;
}
.course-stop.is-charted .stop-marker { background: var(--paper); border-color: var(--paper); }
.course-stop.is-next .stop-marker {
  background: var(--accent);
  border-color: var(--accent);
  box-shadow: 0 0 0 6px var(--accent-soft), 0 0 22px color-mix(in srgb, var(--accent) 40%, transparent);
}
.course-stop button:hover .stop-marker { box-shadow: 0 0 0 6px var(--accent-soft); }
.stop-index { color: var(--muted); font: 400 .6rem var(--mono); letter-spacing: .1em; }
.stop-index b { font-weight: 500; color: var(--accent); }
.course-stop.is-charted .stop-index b { color: var(--paper); }
.course-stop strong { font-size: 1rem; font-weight: 500; line-height: 1.3; letter-spacing: -.01em; }
.course-stop small { max-width: 260px; color: var(--muted); font-size: .76rem; line-height: 1.5; }
.stop-meta { margin-top: auto; padding-top: 8px; color: var(--muted); font: 400 .58rem var(--mono); letter-spacing: .1em; }

.lesson-route,
.context-panel { padding: 34px 28px; background: rgba(248, 250, 249, .78); backdrop-filter: blur(18px); }
.lesson-route { border-right: 1px solid var(--line); display: flex; flex-direction: column; }
.context-panel { border-left: 1px solid var(--line); }

.back-button {
  width: fit-content;
  padding: 0;
  border: 0;
  background: none;
  color: var(--muted);
  font: 500 .65rem var(--mono);
  letter-spacing: .1em;
  cursor: pointer;
}

.back-button:hover { color: var(--accent); }
.route-identity { margin: 48px 0 36px; }
.route-identity h2 { margin: 10px 0 0; font-size: 1.45rem; line-height: 1.18; font-weight: 500; letter-spacing: -.03em; }
.route-nodes { position: relative; list-style: none; padding: 0; margin: 0; flex: 1; }
.route-nodes::before { content: ""; position: absolute; left: 14px; top: 16px; bottom: 50px; width: 1px; background: var(--line-strong); }
.route-node { position: relative; min-height: 70px; padding: 4px 0 0 44px; color: var(--muted); }
.route-dot { position: absolute; left: 8px; top: 4px; width: 13px; height: 13px; border: 1px solid var(--line-strong); border-radius: 50%; background: #fff; }
.route-node.active .route-dot { background: var(--accent); border-color: var(--accent); box-shadow: 0 0 0 5px var(--accent-soft); }
.route-node.complete .route-dot { background: var(--paper); border-color: var(--paper); }
.route-node small { display: block; margin-bottom: 4px; font: 400 .59rem var(--mono); letter-spacing: .08em; }
.route-node strong { display: block; font-size: .78rem; font-weight: 500; }
.route-node.active strong { color: var(--paper); }
.route-footer { color: var(--muted); }
.route-footer > span,
.route-footer > strong { display: inline-block; }
.route-footer > strong { float: right; color: var(--paper); }
.progress-track { clear: both; height: 2px; margin-top: 12px; background: var(--line); }
.progress-track span { display: block; width: 0; height: 100%; background: var(--accent); transition: width 350ms ease; }

.challenge-stage {
  position: relative;
  padding: clamp(34px, 5vw, 72px);
  display: flex;
  flex-direction: column;
  min-height: calc(100vh - 72px);
}

.stage-meta { display: flex; justify-content: space-between; padding-bottom: 18px; border-bottom: 1px solid var(--line); color: var(--muted); }
.challenge-card { width: min(720px, 100%); margin: auto; padding: 50px 0; }
.source-line { color: var(--accent); }
.challenge-card h2 { margin: 18px 0 14px; font-size: clamp(2rem, 4vw, 4.1rem); line-height: 1.03; font-weight: 500; letter-spacing: -.05em; }
.question-context { max-width: 620px; margin: 0 0 36px; color: #536169; font-size: .93rem; line-height: 1.72; }

.answer-area { display: grid; gap: 10px; }
.answer-option { position: relative; display: block; cursor: pointer; }
.answer-option input { position: absolute; opacity: 0; pointer-events: none; }
.answer-option span {
  min-height: 58px;
  padding: 14px 50px 14px 17px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, .82);
  display: flex;
  align-items: center;
  font-size: .86rem;
  transition: border 160ms ease, background 160ms ease;
}
.answer-option span::after { content: attr(data-key); position: absolute; right: 18px; color: var(--muted); font: 400 .65rem var(--mono); }
.answer-option:hover span { border-color: var(--line-strong); background: var(--surface-raised); }
.answer-option input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: 2px; }
.answer-option input:checked + span { border-color: var(--accent); background: var(--accent-soft); }
.answer-option.is-correct span { border-color: #3f7a62; background: rgba(63, 122, 98, .10); }
.answer-option.is-wrong span { border-color: var(--danger); background: rgba(166, 63, 54, .08); }

.fill-answer {
  width: 100%;
  min-height: 70px;
  padding: 0 18px;
  border: 0;
  border-bottom: 1px solid var(--line-strong);
  background: rgba(255,255,255,.72);
  color: var(--paper);
  font-size: 1.2rem;
}
.fill-answer::placeholder { color: #59636b; }
.fill-hint { margin-top: 10px; color: var(--muted); font: 400 .64rem var(--mono); letter-spacing: .06em; }

.binary-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.binary-grid .answer-option span { min-height: 104px; align-items: flex-start; line-height: 1.55; }

.submit-answer {
  width: 100%;
  margin-top: 22px;
  min-height: 54px;
}
.submit-answer:disabled { border-color: var(--line); background: rgba(255,255,255,.56); color: #7b868c; cursor: not-allowed; }

.feedback-panel {
  margin: 0 calc(clamp(34px, 5vw, 72px) * -1) calc(clamp(34px, 5vw, 72px) * -1);
  padding: 24px clamp(34px, 5vw, 72px);
  border-top: 1px solid var(--accent);
  background: color-mix(in srgb, var(--accent) 8%, #ffffff);
  display: grid;
  grid-template-columns: 40px 1fr auto;
  gap: 18px;
  align-items: center;
}
.feedback-panel[hidden] { display: none; }
.feedback-mark { width: 32px; height: 32px; border: 1px solid var(--accent); border-radius: 50%; position: relative; }
.feedback-mark::after { content: ""; position: absolute; width: 10px; height: 5px; border-left: 1px solid var(--accent); border-bottom: 1px solid var(--accent); transform: rotate(-45deg); left: 10px; top: 9px; }
.feedback-panel.incorrect { border-color: var(--danger); background: rgba(166, 63, 54, .06); }
.feedback-panel.incorrect .feedback-mark { border-color: var(--danger); }
.feedback-panel.incorrect .feedback-mark::after { width: 12px; height: 1px; border: 0; background: var(--danger); transform: rotate(45deg); left: 9px; top: 14px; box-shadow: 0 0 0 transparent; }
.feedback-panel.incorrect .feedback-mark::before { content: ""; position: absolute; width: 12px; height: 1px; background: var(--danger); transform: rotate(-45deg); left: 9px; top: 14px; }
.feedback-panel h3 { margin: 4px 0; font-size: 1rem; font-weight: 600; }
.feedback-panel p:not(.eyebrow) { max-width: 700px; margin: 0; color: #58656c; font-size: .78rem; line-height: 1.55; }
.feedback-panel button { min-width: 128px; }

.context-panel { padding-top: 76px; }
.context-panel blockquote { margin: 22px 0 30px; font: 400 italic 1.5rem/1.35 var(--serif); color: #25343b; }
.context-rule { height: 1px; background: var(--line); margin-bottom: 28px; }
.context-panel dl { margin: 0; }
.context-panel dt { margin-top: 20px; color: var(--muted); font: 400 .6rem var(--mono); letter-spacing: .1em; }
.context-panel dd { margin: 6px 0 0; font-size: .8rem; line-height: 1.5; }

dialog {
  width: min(620px, calc(100% - 32px));
  padding: 44px;
  border: 1px solid var(--line-strong);
  background: #ffffff;
  color: var(--paper);
  box-shadow: 0 40px 100px rgba(26, 43, 51, .18);
}
dialog::backdrop { background: rgba(235, 240, 238, .78); backdrop-filter: blur(8px); }
.completion-graphic { position: relative; width: 90px; height: 90px; margin-bottom: 32px; border: 1px solid var(--accent); border-radius: 50%; }
.completion-graphic::before,
.completion-graphic::after { content: ""; position: absolute; inset: 11px; border: 1px solid var(--line-strong); border-radius: 50%; transform: rotate(35deg) scaleY(.48); }
.completion-graphic::after { transform: rotate(-35deg) scaleY(.48); }
.completion-graphic span { position: absolute; left: 50%; top: 50%; width: 6px; height: 6px; transform: translate(-50%,-50%); background: var(--accent); border-radius: 50%; box-shadow: 0 0 18px var(--accent); }
dialog h2 { margin: 10px 0 12px; font-size: 2.6rem; letter-spacing: -.05em; font-weight: 500; }
dialog > p:not(.eyebrow) { color: var(--muted); line-height: 1.65; }
.completion-stats { display: grid; grid-template-columns: 1fr 1fr; border: 1px solid var(--line); margin: 30px 0; }
.completion-stats div { padding: 18px; }
.completion-stats div + div { border-left: 1px solid var(--line); }
.completion-stats strong { display: block; font-size: 1.6rem; font-weight: 500; color: var(--accent); }
.completion-stats span { color: var(--muted); font: 400 .59rem var(--mono); letter-spacing: .09em; }
.dialog-actions { display: flex; justify-content: flex-end; gap: 10px; }
.dialog-actions button:first-child { border-color: var(--line-strong); background: transparent; color: var(--paper); }

.account-button {
  min-height: 36px;
  padding: 0 12px;
  border: 1px solid var(--line);
  background: transparent;
  color: inherit;
  font: inherit;
  letter-spacing: inherit;
  white-space: nowrap;
  cursor: pointer;
}
.account-button:hover { border-color: var(--accent); color: var(--accent); }
.account-button[hidden] { display: none; }
#account-dialog[data-state="signed-in"] .account-signed-out,
#account-dialog[data-state="signed-out"] .account-signed-in { display: none; }
.account-form { margin-top: 26px; }
.account-email {
  width: 100%;
  min-height: 58px;
  margin-bottom: 22px;
  padding: 0 16px;
  border: 0;
  border-bottom: 1px solid var(--line-strong);
  background: var(--surface-raised);
  color: var(--paper);
  font: 400 1rem var(--sans);
}
.account-email:focus { outline: 1px solid var(--accent); outline-offset: 0; }
.account-status { min-height: 1.2em; margin: 18px 0 0; color: var(--muted); font: 400 .66rem/1.6 var(--mono); letter-spacing: .06em; }
.account-status.is-error { color: var(--danger); }

.keyboard-hint {
  position: fixed;
  right: 18px;
  bottom: 14px;
  color: #626d75;
  font: 400 .58rem var(--mono);
  letter-spacing: .08em;
  pointer-events: none;
}

@media (max-width: 1080px) {
  .lesson-screen.is-active { grid-template-columns: 220px 1fr; }
  .context-panel { display: none; }
  .path-layout { grid-template-columns: minmax(340px, .9fr) minmax(380px, 1.1fr); gap: 32px; }
}

@media (max-width: 800px) {
  .hanging-motif { display: none; }
  .topbar { height: 62px; }
  .coordinates,
  .topbar-rule,
  .keyboard-hint { display: none; }
  .screen { min-height: calc(100vh - 62px); }
  .atlas-intro { grid-template-columns: 1fr; gap: 24px; }
  h1 { font-size: clamp(3rem, 13vw, 5rem); }
  .path-layout { grid-template-columns: 1fr; }
  .chart-frame { position: relative; top: 0; min-height: 480px; }
  .lesson-screen.is-active { grid-template-columns: 1fr; }
  .lesson-route { padding: 22px 24px; border-right: 0; border-bottom: 1px solid var(--line); }
  .route-identity { margin: 28px 0 18px; }
  .route-nodes { display: flex; gap: 6px; }
  .route-nodes::before { left: 6%; right: 6%; top: 10px; bottom: auto; width: auto; height: 1px; }
  .route-node { flex: 1; min-height: 48px; padding: 28px 2px 0; text-align: center; }
  .route-dot { left: 50%; top: 4px; transform: translateX(-50%); }
  .route-node strong { display: none; }
  .route-footer { margin-top: 14px; }
  .challenge-stage { min-height: auto; padding: 32px 24px 0; }
  .challenge-card { margin: 22px auto auto; padding: 30px 0; }
  .feedback-panel { margin: 0 -24px; padding: 22px 24px; grid-template-columns: 32px 1fr; }
  .feedback-panel button { grid-column: 1 / -1; width: 100%; }
  .course-route { grid-template-columns: 1fr; }
  .course-route::before,
  .course-line { display: none; }
  .course-route::after { content: ""; position: absolute; left: 22px; top: 28px; bottom: 28px; border-left: 1px dashed var(--line-strong); }
  .course-stop button { padding: 20px 12px 20px 52px; align-items: flex-start; text-align: left; border-bottom: 1px solid var(--line); }
  .stop-marker { left: 22px; top: 29px; z-index: 1; }
  .stop-meta { margin-top: 2px; padding-top: 0; }
}

@media (max-width: 540px) {
  .atlas-screen { padding-left: 20px; padding-right: 20px; }
  .discipline-tab { padding: 14px 12px; gap: 10px; }
  .discipline-tab small { display: none; }
  .path-button { grid-template-columns: 42px 1fr; min-height: 108px; padding-right: 30px; }
  .path-status { grid-column: 2; }
  .chart-frame { min-height: 520px; }
  .orbit-two { width: 310px; }
  .binary-grid { grid-template-columns: 1fr; }
  .stage-meta { gap: 12px; }
  .challenge-card h2 { font-size: 2.25rem; }
  dialog { padding: 30px 24px; }
  .topbar-meta { gap: 10px; }
  #field-notes { white-space: nowrap; }
  .dialog-actions { flex-direction: column; }
  .dialog-actions button { width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; scroll-behavior: auto !important; }
}