:root {
  --bg: #fcfbfd;
  --text-primary: #23212c;
  --text-secondary: #585566;
  --text-muted: #817d8f;
  --accent: #6c5ce7;
  --rule: #e8e5ee;
  --header-height: 70px;
  --page-width: 1440px;
  --reading-width: 1000px;
  --navigation-width: 220px;
  --drawer-width: 480px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  background: var(--bg);
  color: var(--text-primary);
  font-family: "Inter", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.8;
  margin: 0;
}

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

button {
  font: inherit;
}

.visually-hidden {
  height: 1px;
  overflow: hidden;
  position: absolute;
  width: 1px;
  clip-path: inset(50%);
}

.topic-topbar {
  backdrop-filter: blur(16px);
  background: rgb(252 251 253 / 88%);
  border-bottom: 1px solid rgb(232 229 238 / 70%);
  height: var(--header-height);
  inset: 0 0 auto;
  position: fixed;
  z-index: 30;
}

.topbar-inner {
  align-items: center;
  display: flex;
  height: 100%;
  justify-content: space-between;
  margin: 0 auto;
  max-width: var(--page-width);
  padding: 0 42px;
}

.brand {
  align-items: center;
  display: inline-flex;
  font-size: 13px;
  font-weight: 600;
  gap: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.brand-dot {
  background: var(--accent);
  border-radius: 50%;
  height: 8px;
  width: 8px;
}

.topbar-actions {
  align-items: center;
  display: flex;
  gap: 26px;
}

.preview-label {
  color: var(--text-secondary);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.back-module-link {
  border-left: 1px solid var(--rule);
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 500;
  padding-left: 26px;
}

.back-module-link:hover {
  color: var(--text-primary);
}

.page {
  column-gap: 60px;
  display: grid;
  grid-template-columns: var(--navigation-width) minmax(0, var(--reading-width));
  justify-content: center;
  margin: 0 auto;
  max-width: var(--page-width);
  padding: calc(var(--header-height) + 72px) 42px 100px;
  transition: column-gap 200ms ease;
}

body.navigation-collapsed .page {
  column-gap: 0;
  grid-template-columns: 0 minmax(0, var(--reading-width));
}

.navigation-drawer {
  min-width: 0;
  opacity: 1;
  transform: translateX(0);
  transition: opacity 180ms ease, transform 200ms ease, visibility 200ms ease;
}

body.navigation-collapsed .navigation-drawer {
  opacity: 0;
  pointer-events: none;
  transform: translateX(-28px);
  visibility: hidden;
}

.toc {
  position: sticky;
  top: calc(var(--header-height) + 72px);
}

.toc-label {
  color: var(--text-muted);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.16em;
  margin: 0 0 26px;
  text-transform: uppercase;
}

.toc a {
  border-left: 1px solid var(--rule);
  color: var(--text-secondary);
  display: block;
  padding: 8px 0 8px 22px;
}

.toc a:hover {
  border-color: var(--accent);
  color: var(--text-primary);
}

.navigation-toggle,
.calculation-drawer-toggle {
  align-items: center;
  background: #181720;
  border: 1px solid #494653;
  border-radius: 11px;
  color: #fff;
  cursor: pointer;
  display: inline-flex;
  height: 46px;
  justify-content: center;
  position: fixed;
  top: calc(var(--header-height) + 22px);
  width: 46px;
  z-index: 36;
}

.navigation-toggle {
  left: 20px;
}

.calculation-drawer-toggle {
  border-color: var(--rule);
  border-radius: 50%;
  color: var(--text-primary);
  background: var(--bg);
  right: 20px;
  width: 56px;
  height: 56px;
}

.navigation-toggle:hover,
.navigation-toggle[aria-expanded="false"] {
  background: #2d2b37;
}

.calculation-drawer-toggle:hover,
.calculation-drawer-toggle[aria-expanded="true"] {
  border-color: var(--accent);
  color: var(--accent);
}

.sidebar-icon {
  display: block;
  height: 20px;
  stroke: currentcolor;
  width: 20px;
}

.drawer-icon {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.drawer-icon span {
  background: currentcolor;
  height: 1.5px;
  width: 22px;
}

main {
  min-width: 0;
}

.hero {
  border-bottom: 1px solid var(--rule);
  margin-bottom: 70px;
  padding-bottom: 62px;
}

.kicker {
  color: var(--accent);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.2em;
  margin: 0 0 26px;
  text-transform: uppercase;
}

h1,
h2 {
  color: var(--text-primary);
  font-family: "Instrument Serif", Georgia, serif;
  font-weight: 400;
  letter-spacing: -0.02em;
  line-height: 1.04;
  margin: 0;
}

h1 {
  font-size: clamp(60px, 7vw, 86px);
  max-width: 850px;
}

.lede {
  color: var(--text-secondary);
  font-size: 21px;
  line-height: 1.68;
  margin: 36px 0 0;
  max-width: 820px;
}

.hero-meta {
  color: var(--text-muted);
  display: flex;
  font-size: 12px;
  gap: 26px;
  letter-spacing: 0.16em;
  margin-top: 48px;
  text-transform: uppercase;
}

.content-section {
  margin-bottom: 76px;
  scroll-margin-top: calc(var(--header-height) + 34px);
}

.section-kicker {
  color: var(--text-muted);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.16em;
  margin: 0 0 18px;
  text-transform: uppercase;
}

.content-section h2 {
  font-size: clamp(40px, 4vw, 55px);
  margin-bottom: 28px;
}

.section-intro {
  color: var(--text-secondary);
  font-size: 18px;
  margin: 0 0 32px;
  max-width: 780px;
}

.interactive-stage {
  margin-top: 30px;
  width: 100%;
}

.evaluation-interaction {
  border-top: 1px solid var(--rule);
  color: var(--text-primary);
  padding-top: 26px;
}

.evaluation-explore-line {
  color: var(--text-primary);
  font-family: "Instrument Serif", Georgia, serif;
  font-size: 26px;
  margin-bottom: 28px;
}

.evaluation-explore-line span:first-child {
  font-family: "Inter", Arial, sans-serif;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.15em;
  margin-right: 12px;
  text-transform: uppercase;
}

.evaluation-arrow {
  color: var(--accent);
  margin: 0 12px;
}

.evaluation-controls {
  align-items: center;
  border-bottom: 1px solid var(--rule);
  border-top: 1px solid var(--rule);
  display: flex;
  gap: 24px;
  justify-content: space-between;
  padding: 18px 0;
}

.evaluation-metric-controls {
  display: flex;
  gap: 8px;
}

.evaluation-metric-controls button {
  background: transparent;
  border: 1px solid var(--rule);
  border-radius: 999px;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  padding: 7px 18px;
}

.evaluation-metric-controls button.is-selected {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.evaluation-threshold-control {
  align-items: center;
  color: var(--text-secondary);
  display: flex;
  font-size: 13px;
  font-weight: 600;
  gap: 12px;
}

.evaluation-threshold-control input {
  accent-color: var(--accent);
  width: 190px;
}

.evaluation-threshold-control output {
  color: var(--text-primary);
  min-width: 36px;
}

.evaluation-legend {
  color: var(--text-secondary);
  display: flex;
  flex-wrap: wrap;
  font-size: 12px;
  font-weight: 500;
  gap: 24px;
  padding: 18px 0;
}

.evaluation-legend span {
  align-items: center;
  display: inline-flex;
  gap: 8px;
}

.evaluation-dot {
  border-radius: 50%;
  display: inline-block;
  height: 9px;
  width: 9px;
}

.evaluation-dot.tp,
.evaluation-score-strip .tp {
  background: #48a681;
  fill: #48a681;
}

.evaluation-dot.fp,
.evaluation-score-strip .fp {
  background: #e47d53;
  fill: #e47d53;
}

.evaluation-dot.fn,
.evaluation-score-strip .fn {
  background: #ddb136;
  fill: #ddb136;
}

.evaluation-dot.tn,
.evaluation-score-strip .tn {
  background: #7664df;
  fill: #7664df;
}

.evaluation-score-region {
  border-bottom: 1px solid var(--rule);
  border-top: 1px solid var(--rule);
  padding: 22px 0 16px;
}

.evaluation-score-region h3,
.evaluation-matrix-region h3,
.evaluation-metrics-region h3 {
  color: var(--text-primary);
  font-family: "Instrument Serif", Georgia, serif;
  font-size: 26px;
  font-weight: 400;
  margin: 0 0 12px;
}

.evaluation-score-strip {
  display: block;
  height: auto;
  width: 100%;
}

.evaluation-score-strip text {
  fill: var(--text-muted);
  font-family: "Inter", Arial, sans-serif;
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.evaluation-score-strip .negative-region {
  fill: #f0eefc;
}

.evaluation-score-strip .positive-region {
  fill: #eef8f3;
}

.evaluation-score-strip .threshold-line {
  stroke: var(--accent);
  stroke-dasharray: 5 5;
  stroke-width: 2;
}

.evaluation-score-strip .threshold-label {
  fill: var(--accent);
}

.evaluation-score-strip .threshold-text {
  fill: #fff;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0;
}

.evaluation-score-strip .range-text {
  letter-spacing: 0;
}

.evaluation-scale-labels {
  color: var(--text-muted);
  display: flex;
  font-size: 12px;
  justify-content: space-between;
  margin-top: 4px;
}

.evaluation-results {
  display: grid;
  gap: 44px;
  grid-template-columns: minmax(290px, 0.88fr) minmax(360px, 1.12fr);
  padding: 34px 0 30px;
}

.evaluation-confusion-matrix {
  align-items: center;
  display: grid;
  gap: 8px;
  grid-template-columns: 72px 1fr 1fr;
}

.matrix-axis {
  color: var(--text-muted);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-align: center;
  text-transform: uppercase;
}

.matrix-value {
  align-items: center;
  border-radius: 10px;
  display: flex;
  flex-direction: column;
  height: 86px;
  justify-content: center;
  opacity: 0.56;
  transition: opacity 140ms ease, transform 140ms ease;
}

.matrix-value.tp {
  background: #e1f3ed;
}

.matrix-value.fp {
  background: #fce9e0;
}

.matrix-value.fn {
  background: #fbf3db;
}

.matrix-value.tn {
  background: #eeebfb;
}

.matrix-value.is-relevant {
  opacity: 1;
  transform: translateY(-1px);
}

.matrix-value b {
  color: var(--text-secondary);
  font-size: 12px;
}

.matrix-value strong {
  color: var(--text-primary);
  font-size: 27px;
  font-weight: 600;
  line-height: 1.25;
}

.evaluation-total {
  color: var(--text-muted);
  font-size: 12px;
  margin: 17px 0 0 80px;
}

.evaluation-metric-grid {
  display: grid;
  gap: 0 26px;
  grid-template-columns: 1fr 1fr;
}

.evaluation-metric-item {
  background: transparent;
  border: 0;
  border-top: 1px solid var(--rule);
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  flex-direction: column;
  min-height: 106px;
  padding: 14px 0;
  text-align: left;
}

.evaluation-metric-item.is-selected {
  border-top-color: var(--accent);
  color: var(--text-primary);
}

.evaluation-metric-item span {
  color: var(--text-primary);
  font-size: 14px;
  font-weight: 600;
}

.evaluation-metric-item small {
  color: var(--text-muted);
  font-family: Georgia, serif;
  font-size: 14px;
  margin: 5px 0 5px;
}

.evaluation-metric-item strong {
  color: var(--text-primary);
  font-size: 23px;
  font-weight: 500;
}

.evaluation-live-reading {
  border-top: 1px solid var(--rule);
  display: grid;
  gap: 14px 28px;
  grid-template-columns: 126px minmax(240px, 300px) 1fr;
  padding: 22px 0 8px;
}

.evaluation-selected-label {
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
  margin: 0;
}

.evaluation-live-formula {
  color: var(--text-primary);
  font-size: 16px;
  min-height: 32px;
}

.evaluation-live-formula mjx-container[display="true"] {
  margin: 0 !important;
  overflow: visible !important;
}

.evaluation-insight {
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.65;
  margin: 0;
}

.bias-interaction {
  border-top: 1px solid var(--rule);
  color: var(--text-primary);
  padding-top: 26px;
}

.bias-explore-line {
  color: var(--text-primary);
  font-family: "Instrument Serif", Georgia, serif;
  font-size: 26px;
  margin-bottom: 28px;
}

.bias-explore-line > span:first-child {
  font-family: "Inter", Arial, sans-serif;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.15em;
  margin-right: 12px;
  text-transform: uppercase;
}

.bias-explore-line span:not(:first-child) {
  color: var(--accent);
  margin: 0 12px;
}

.bias-toolbar {
  border-bottom: 1px solid var(--rule);
  border-top: 1px solid var(--rule);
  display: flex;
  gap: 36px;
  justify-content: space-between;
  padding: 20px 0;
}

.bias-choice-group {
  border: 0;
  margin: 0;
  padding: 0;
}

.bias-choice-group legend {
  color: var(--text-muted);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  margin-bottom: 12px;
  text-transform: uppercase;
}

.bias-choice-group > div {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.bias-choice-group button,
.bias-baseline-row button {
  background: transparent;
  border: 1px solid var(--rule);
  border-radius: 999px;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 13px;
  padding: 6px 15px;
}

.bias-choice-group button.is-selected,
.bias-baseline-row button.is-selected {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.bias-input-grid {
  border-bottom: 1px solid var(--rule);
  display: grid;
  gap: 23px;
  grid-template-columns: repeat(5, 1fr);
  padding: 27px 0 24px;
}

.bias-input {
  display: grid;
  gap: 10px;
  grid-template-columns: 1fr auto;
}

.bias-input span {
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 600;
}

.bias-input output {
  color: var(--text-primary);
  font-size: 13px;
  font-weight: 600;
}

.bias-input input {
  accent-color: var(--accent);
  grid-column: 1 / -1;
  width: 100%;
}

.bias-baseline-row {
  align-items: center;
  border-bottom: 1px solid var(--rule);
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
  padding: 18px 0;
}

.bias-baseline-row > span {
  color: var(--text-muted);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  margin-right: 11px;
  text-transform: uppercase;
}

.bias-results-layout {
  display: grid;
  gap: 46px;
  grid-template-columns: minmax(470px, 1fr) minmax(260px, 300px);
  padding-top: 35px;
}

.bias-error-region h3,
.bias-curve-region h3,
.bias-diagnosis-result h3 {
  font-family: "Instrument Serif", Georgia, serif;
  font-size: 28px;
  font-weight: 400;
  line-height: 1.3;
  margin: 0 0 4px;
}

.bias-error-region > p,
.bias-curve-region > p {
  color: var(--text-muted);
  font-size: 13px;
  margin: 0 0 24px;
}

.bias-error-stack {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.bias-error-row {
  align-items: center;
  display: grid;
  gap: 14px;
  grid-template-columns: 138px minmax(0, 1fr) 54px;
}

.bias-error-row > span,
.bias-error-row output {
  color: var(--text-secondary);
  font-size: 13px;
}

.bias-error-row output {
  text-align: right;
}

.bias-bar-track {
  background: #eeebf2;
  border-radius: 999px;
  height: 9px;
  overflow: hidden;
}

.bias-bar-fill {
  border-radius: inherit;
  display: block;
  height: 100%;
  transition: width 180ms ease;
}

.bias-bar-fill.human {
  background: #bbb6c7;
}

.bias-bar-fill.train {
  background: #4b91e3;
}

.bias-bar-fill.train-dev {
  background: #7664df;
}

.bias-bar-fill.dev {
  background: #dc9760;
}

.bias-bar-fill.test {
  background: #4da77f;
}

.bias-gap-grid {
  display: grid;
  gap: 0 24px;
  grid-template-columns: repeat(4, 1fr);
  margin-top: 35px;
}

.bias-gap {
  border-top: 1px solid var(--rule);
  display: flex;
  flex-direction: column;
  min-height: 116px;
  padding: 14px 0 0;
}

.bias-gap > span {
  color: var(--text-muted);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.bias-gap strong {
  color: var(--text-primary);
  font-size: 28px;
  font-weight: 500;
  line-height: 1.3;
  margin: 7px 0 3px;
}

.bias-gap small {
  color: var(--text-secondary);
  font-size: 12px;
  line-height: 1.45;
}

.bias-curve-region {
  border-top: 1px solid var(--rule);
  margin-top: 34px;
  padding-top: 26px;
}

.bias-curve-region svg {
  display: block;
  height: auto;
  width: 100%;
}

.bias-curve-region svg text {
  fill: var(--text-muted);
  font-family: "Inter", Arial, sans-serif;
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.bias-grid-line {
  stroke: var(--rule);
  stroke-width: 1;
}

.bias-curve-train,
.bias-curve-dev {
  fill: none;
  stroke-linecap: round;
  stroke-width: 3;
}

.bias-curve-train {
  stroke: #4b91e3;
}

.bias-curve-dev {
  stroke: #dc8450;
}

.bias-curve-train-point {
  fill: #4b91e3;
}

.bias-curve-dev-point {
  fill: #dc8450;
}

.bias-diagnosis-result {
  border-left: 1px solid var(--rule);
  padding-left: 30px;
}

.bias-result-label {
  color: var(--accent);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  margin: 0 0 11px;
  text-transform: uppercase;
}

.bias-diagnosis-result[data-kind="bias"] .bias-result-label {
  color: #c45f49;
}

.bias-diagnosis-result[data-kind="variance"] .bias-result-label {
  color: #c37a43;
}

.bias-diagnosis-result[data-kind="good"] .bias-result-label {
  color: #3b946b;
}

.bias-diagnosis-result dl {
  display: grid;
  gap: 0;
  margin: 23px 0 24px;
}

.bias-diagnosis-result dl div {
  border-top: 1px solid var(--rule);
  display: flex;
  justify-content: space-between;
  padding: 12px 0;
}

.bias-diagnosis-result dt {
  color: var(--text-muted);
  font-size: 12px;
}

.bias-diagnosis-result dd {
  color: var(--text-primary);
  font-size: 14px;
  font-weight: 600;
  margin: 0;
}

.bias-reason {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.72;
  margin: 0;
}

.prototype-frame {
  background: transparent;
  border: 0;
  display: block;
  min-height: 720px;
  overflow: hidden;
  width: 100%;
}

.reading-copy p {
  color: var(--text-secondary);
  font-size: 18px;
  line-height: 1.85;
  margin: 0 0 22px;
}

.formula-row {
  border-bottom: 1px solid var(--rule);
  padding: 0 0 30px;
  margin-bottom: 30px;
}

.formula-expression {
  color: var(--text-primary);
  font-family: Georgia, serif;
  font-size: 30px;
  line-height: 1.55;
  margin-bottom: 12px;
}

.formula-explanation,
.reading-list li {
  color: var(--text-secondary);
  font-size: 17px;
}

.lesson-formula {
  color: var(--text-primary);
  font-size: 28px;
  line-height: 1.55;
  margin: 26px 0 30px;
  overflow: visible;
}

.lesson-formula.compact {
  font-size: 24px;
  margin: 20px 0 28px;
}

.lesson-formula mjx-container[display="true"] {
  margin: 20px 0 !important;
  overflow: visible !important;
}

.lesson-quote {
  border-left: 2px solid var(--accent);
  color: var(--text-primary);
  font-size: 22px;
  line-height: 1.62;
  margin: 28px 0 34px;
  padding: 2px 0 2px 28px;
}

.lesson-code {
  background: transparent;
  border-left: 2px solid var(--rule);
  color: var(--text-primary);
  font-family: "Inter", Arial, sans-serif;
  font-size: 18px;
  line-height: 1.8;
  margin: 25px 0 32px;
  padding: 3px 0 3px 27px;
  white-space: pre-wrap;
}

.reading-subheading {
  color: var(--text-primary);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.15em;
  margin: 48px 0 22px;
  text-transform: uppercase;
}

.lesson-table {
  border-collapse: collapse;
  color: var(--text-secondary);
  font-size: 17px;
  margin: 24px 0 42px;
  width: 100%;
}

.lesson-table th,
.lesson-table td {
  border-bottom: 1px solid var(--rule);
  padding: 15px 18px 15px 0;
  text-align: left;
}

.lesson-table thead th {
  color: var(--text-muted);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.matrix-table td {
  color: var(--text-primary);
  font-size: 20px;
}

.example-table td:last-child,
.example-table th:last-child {
  text-align: right;
}

.diagnosis-table td:first-child {
  color: var(--text-primary);
  white-space: nowrap;
}

.diagnosis-table td:last-child {
  color: var(--text-primary);
  font-weight: 600;
}

.metric-formula-list {
  margin: 24px 0 36px;
}

.metric-formula-list .lesson-formula {
  margin: 0 0 18px;
}

.symbol-list {
  margin: 0;
}

.symbol-list div {
  border-top: 1px solid var(--rule);
  display: grid;
  gap: 28px;
  grid-template-columns: 128px 1fr;
  padding: 18px 0;
}

.symbol-list dt {
  color: var(--text-primary);
  font-size: 22px;
}

.symbol-list dd {
  color: var(--text-secondary);
  font-size: 17px;
  margin: 0;
}

.workflow-list {
  color: var(--text-secondary);
  font-size: 18px;
  margin: 0;
  padding-left: 26px;
}

.workflow-list li {
  border-top: 1px solid var(--rule);
  padding: 14px 0 14px 10px;
}

.metric-reading-list {
  display: grid;
  gap: 0 42px;
  grid-template-columns: 1fr 1fr;
}

.metric-reading-list article {
  border-top: 1px solid var(--rule);
  padding: 22px 0 28px;
}

.metric-reading-list h3 {
  color: var(--text-primary);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.13em;
  margin: 0 0 14px;
  text-transform: uppercase;
}

.metric-reading-list p {
  color: var(--text-secondary);
  font-size: 17px;
  line-height: 1.75;
  margin: 0 0 10px;
}

.metric-reading-list .lesson-quote {
  font-size: 18px;
  margin: 15px 0 21px;
  padding-left: 18px;
}

.takeaway {
  border-top: 1px solid var(--rule);
  padding-top: 54px;
}

.structure-reading-list {
  display: grid;
  gap: 0 42px;
  grid-template-columns: 1fr 1fr;
}

.structure-reading-list article {
  border-top: 1px solid var(--rule);
  padding: 22px 0 30px;
}

.structure-reading-list article:last-child {
  grid-column: 1 / -1;
}

.structure-reading-list h3 {
  color: var(--text-primary);
  font-family: "Instrument Serif", Georgia, serif;
  font-size: 29px;
  font-weight: 400;
  margin: 0 0 12px;
}

.structure-reading-list p {
  font-size: 16px;
  margin-bottom: 12px;
}

.two-column {
  display: grid;
  gap: 40px;
  grid-template-columns: 1fr 1fr;
}

.reading-heading {
  color: var(--text-primary);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.15em;
  margin: 0 0 22px;
  text-transform: uppercase;
}

.reading-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.reading-list li {
  border-top: 1px solid var(--rule);
  line-height: 1.72;
  padding: 17px 0;
}

.explanatory-list li {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.explanatory-list strong {
  color: var(--text-primary);
  font-weight: 600;
}

.explanatory-list span {
  color: var(--text-secondary);
}

.takeaway-section {
  border-top: 1px solid var(--rule);
  padding-top: 42px;
}

.derivation-launchers {
  display: grid;
  gap: 15px;
  grid-template-columns: 1fr 1fr;
  margin-top: 34px;
}

.derivation-launcher {
  background: transparent;
  border: 1px solid var(--rule);
  border-radius: 5px;
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: 11px;
  min-height: 126px;
  padding: 24px 25px;
  text-align: left;
  transition: background 160ms ease, border-color 160ms ease;
}

.derivation-launcher:hover {
  background: #f8f7fc;
  border-color: var(--accent);
}

.derivation-launcher strong {
  font-family: "Instrument Serif", Georgia, serif;
  font-size: 29px;
  font-weight: 400;
}

.derivation-launcher span {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.55;
}

.reserved-section {
  border-top: 1px solid var(--rule);
  min-height: 118px;
  padding-top: 14px;
}

.reserved-section p {
  color: var(--text-muted);
  font-size: 14px;
  letter-spacing: 0.03em;
  margin: 0;
}

.calculation-drawer {
  background: var(--bg);
  border-left: 1px solid var(--rule);
  bottom: 0;
  box-shadow: -22px 0 40px rgb(35 33 44 / 7%);
  opacity: 0;
  overflow-y: auto;
  padding: 34px 40px 70px;
  pointer-events: none;
  position: fixed;
  right: 0;
  top: var(--header-height);
  transform: translateX(100%);
  transition: transform 230ms ease, opacity 230ms ease;
  width: min(var(--drawer-width), calc(100vw - 72px));
  z-index: 40;
}

.calculation-drawer.is-open {
  opacity: 1;
  pointer-events: auto;
  transform: translateX(0);
}

.drawer-header {
  align-items: flex-start;
  border-bottom: 1px solid var(--rule);
  display: flex;
  justify-content: space-between;
  margin-bottom: 34px;
  padding-bottom: 22px;
}

.drawer-label {
  color: var(--text-muted);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.16em;
  margin: 0 0 9px;
  text-transform: uppercase;
}

.drawer-header h2 {
  font-size: 39px;
}

.drawer-close {
  background: transparent;
  border: 0;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 28px;
  line-height: 1;
  padding: 8px;
}

.drawer-reading-block {
  border-bottom: 1px solid var(--rule);
  margin-bottom: 32px;
  padding-bottom: 32px;
}

.drawer-reading-block h3 {
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  margin: 0 0 18px;
  text-transform: uppercase;
}

.drawer-tabs {
  border-bottom: 1px solid var(--rule);
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-bottom: 24px;
  padding-bottom: 22px;
}

.drawer-tabs button {
  background: transparent;
  border: 1px solid var(--rule);
  border-radius: 999px;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 13px;
  padding: 7px 14px;
}

.drawer-tabs button.is-selected {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.drawer-panel {
  display: none;
}

.drawer-panel.is-selected {
  display: block;
}

.derivation-section h3 {
  color: var(--text-primary);
  font-size: 15px;
  font-weight: 600;
  margin: 0 0 9px;
  padding-top: 25px;
}

.derivation-section h3:first-child {
  padding-top: 0;
}

.derivation-section p {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.7;
  margin: 4px 0 12px;
}

.derivation-section .lesson-formula {
  font-size: 16px;
  margin: 0 0 12px;
  padding: 5px 0;
}

.mirror-content {
  color: var(--text-primary);
  font-size: 17px;
  line-height: 1.75;
}

.mirror-content > * + * {
  margin-top: 12px;
}

.drawer-math-reading {
  color: var(--text-secondary);
}

.drawer-math-reading mjx-container[display="true"] {
  color: var(--text-primary);
  margin: 18px 0 !important;
  overflow: visible !important;
}

.preview-dropout .drawer-math-reading mjx-container[display="true"] {
  font-size: 76% !important;
}

.drawer-math-reading svg {
  max-width: 100%;
}

.drawer-empty {
  min-height: calc(100vh - 190px);
}

.navigation-backdrop,
.drawer-backdrop {
  background: rgb(35 33 44 / 20%);
  border: 0;
  display: none;
  inset: var(--header-height) 0 0;
  position: fixed;
  z-index: 33;
}

body.drawer-open .drawer-backdrop {
  display: block;
  z-index: 39;
}

@media (max-width: 980px) {
  .topbar-inner {
    padding: 0 20px;
  }

  .preview-label {
    display: none;
  }

  .back-module-link {
    border: 0;
    padding-left: 0;
  }

  .page {
    display: block;
    padding: calc(var(--header-height) + 52px) 22px 72px;
  }

  .navigation-drawer {
    background: var(--bg);
    border-right: 1px solid var(--rule);
    bottom: 0;
    box-shadow: 12px 0 34px rgb(35 33 44 / 8%);
    left: 0;
    padding: 84px 32px 32px;
    position: fixed;
    top: var(--header-height);
    transform: translateX(-102%);
    visibility: visible;
    width: min(312px, calc(100vw - 38px));
    z-index: 34;
  }

  body.navigation-mobile-open .navigation-drawer {
    transform: translateX(0);
  }

  .toc {
    position: static;
  }

  .navigation-toggle {
    left: 16px;
    top: calc(var(--header-height) + 16px);
  }

  .calculation-drawer-toggle {
    right: 16px;
    top: calc(var(--header-height) + 16px);
  }

  h1 {
    font-size: clamp(46px, 13vw, 64px);
  }

  .lede {
    font-size: 18px;
  }

  .hero {
    padding-bottom: 48px;
  }

  .two-column {
    grid-template-columns: 1fr;
  }

  .derivation-launchers {
    grid-template-columns: 1fr;
  }

  .evaluation-controls,
  .evaluation-live-reading {
    align-items: flex-start;
    display: flex;
    flex-direction: column;
  }

  .evaluation-metric-controls {
    flex-wrap: wrap;
  }

  .evaluation-threshold-control input {
    width: min(50vw, 190px);
  }

  .evaluation-results,
  .evaluation-metric-grid {
    grid-template-columns: 1fr;
  }

  .bias-toolbar,
  .bias-baseline-row {
    align-items: flex-start;
    flex-direction: column;
  }

  .bias-input-grid,
  .bias-results-layout,
  .bias-gap-grid {
    grid-template-columns: 1fr;
  }

  .bias-error-row {
    grid-template-columns: 112px minmax(0, 1fr) 52px;
  }

  .bias-gap {
    min-height: 0;
    padding-bottom: 18px;
  }

  .bias-diagnosis-result {
    border-left: 0;
    border-top: 1px solid var(--rule);
    padding-left: 0;
    padding-top: 28px;
  }

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

  .structure-reading-list {
    grid-template-columns: 1fr;
  }

  .structure-reading-list article:last-child {
    grid-column: auto;
  }

  .symbol-list div {
    gap: 10px;
    grid-template-columns: 1fr;
  }

  .lesson-formula {
    font-size: 22px;
  }

  .lesson-quote {
    font-size: 19px;
    padding-left: 20px;
  }

  .lesson-table {
    display: block;
    overflow-x: auto;
  }

  .calculation-drawer {
    padding: 30px 24px 54px;
    width: 100%;
  }

  body.navigation-mobile-open .navigation-backdrop {
    display: block;
    left: min(312px, calc(100vw - 38px));
  }
}