@font-face {
  font-family: Onest;
  src: url("../lab/assets/Onest.ttf") format("truetype");
  font-weight: 100 900;
  font-display: swap;
}
:root {
  --ink: #182a25;
  --green: #17684b;
  --muted: #69766f;
  --mint: #f0f6f3;
  --border: #dce5df;
}
* {
  box-sizing: border-box;
}
html {
  scroll-behavior: auto;
  scroll-padding-top: 30px;
}
body {
  margin: 0;
  background: #fff;
  color: var(--ink);
  font-family: Onest, system-ui, sans-serif;
  font-size: 18px;
  line-height: 1.55;
}
a {
  color: inherit;
  text-decoration: none;
}
button,
input {
  font: inherit;
  color: inherit;
}
button,
a,
input,
summary {
  touch-action: manipulation;
}
button {
  cursor: pointer;
}
button:disabled {
  cursor: default;
  opacity: 0.55;
}
:focus-visible {
  outline: 3px solid #60a68a;
  outline-offset: 4px;
}
h1,
h2,
h3,
p {
  margin: 0;
}
h1 {
  font-size: 58px;
  line-height: 1.12;
  letter-spacing: -2.3px;
  font-weight: 650;
}
h2 {
  font-size: 44px;
  line-height: 1.18;
  letter-spacing: -1.6px;
  font-weight: 650;
}
h3 {
  font-size: 24px;
  line-height: 1.35;
  letter-spacing: -0.5px;
}
p {
  color: var(--muted);
}
.wrap {
  max-width: 1408px;
  margin: auto;
  width: calc(100% - 128px);
}
.section {
  padding: 108px 0;
}
.lead {
  font-size: 21px;
  line-height: 1.55;
  margin-top: 24px;
}
.micro {
  font-size: 14px;
}
.green {
  color: var(--green);
}
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  min-height: 54px;
  padding: 13px 24px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: white;
  font-size: 16px;
  font-weight: 550;
  line-height: 1.4;
}
.button.primary {
  background: var(--green);
  color: #fff;
  border-color: var(--green);
}
.button:hover {
  border-color: var(--green);
}
.primary:hover {
  background: #105539;
}
.text-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--green);
  font-size: 16px;
  font-weight: 550;
}
.actions {
  display: flex;
  align-items: center;
  gap: 24px;
  flex-wrap: wrap;
  margin-top: 32px;
}
.skip {
  position: absolute;
  top: -100px;
  left: 20px;
  background: white;
  padding: 12px;
  z-index: 20;
}
.skip:focus {
  top: 10px;
}
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  padding: 26px 0;
}
.brand {
  font-size: 30px;
  font-weight: 680;
  letter-spacing: -1px;
  line-height: 1;
}
.brand span {
  color: var(--green);
}
.nav {
  display: flex;
  gap: 32px;
  align-items: center;
  font-size: 16px;
}
.nav a:hover {
  color: var(--green);
}
.header > .button {
  min-height: 44px;
  padding: 9px 24px;
}
.hero {
  padding: 56px 0 72px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 72px;
  align-items: center;
}
.hero h1 {
  max-width: 680px;
}
.hero .lead {
  max-width: 610px;
}
.hero .micro {
  margin-top: 22px;
}
.hero-b {
  text-align: center;
  padding: 48px 0 40px;
  max-width: 980px;
  margin: auto;
}
.hero-b h1 {
  font-size: 62px;
}
.hero-b .lead {
  max-width: 850px;
  margin: 24px auto;
}
.hero-b .actions {
  justify-content: center;
}
.hero-b .micro {
  margin-top: 16px;
}
.stage-band {
  background: var(--mint);
  padding: 40px 0;
}
.stage {
  display: grid;
  grid-template-columns: 180px minmax(0, 1fr) 280px;
  gap: 40px;
  align-items: center;
}
.stage .lesson {
  background: white;
}
.stage-copy {
  border-left: 1px solid var(--border);
  padding-left: 30px;
}
.stage-copy h3 {
  font-size: 28px;
}
.stage-copy p {
  font-size: 17px;
  margin-top: 16px;
}
.tabs {
  display: flex;
  flex-direction: column;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}
.tabs button {
  background: #fff;
  text-align: left;
  border: 0;
  border-bottom: 1px solid var(--border);
  padding: 16px;
  font-size: 17px;
}
.tabs button:last-child {
  border-bottom: 0;
}
.tabs button[aria-selected="true"] {
  background: var(--green);
  color: white;
}
.lesson {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px;
  min-width: 0;
}
.lesson-label {
  font-size: 15px;
  margin-bottom: 24px;
}
.lesson h3 {
  font-size: 27px;
  margin-bottom: 18px;
}
.model-row {
  display: flex;
  align-items: center;
  gap: 30px;
  justify-content: center;
  min-height: 230px;
}
.circle {
  width: 240px;
  height: 240px;
  flex-shrink: 0;
}
.circle path {
  fill: white;
  stroke: var(--ink);
  stroke-width: 1.4;
  cursor: pointer;
  transition: fill 0.3s;
}
.circle path.selected {
  fill: var(--green);
}
.circle path:hover {
  fill: #c2ddcf;
}
.circle path.selected:hover {
  fill: #267f5f;
}
.circle path:focus {
  outline: none;
  stroke: #4c9c7a;
  stroke-width: 5;
}
.equation {
  font-size: 35px;
  line-height: 1.4;
  letter-spacing: -1px;
  white-space: nowrap;
}
.fraction {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  vertical-align: middle;
  font-size: 34px;
  line-height: 1.25;
  margin: 0 6px;
}
.fraction span:first-child {
  border-bottom: 2px solid var(--ink);
  min-width: 35px;
  text-align: center;
}
.feedback {
  min-height: 76px;
  background: var(--mint);
  color: var(--green);
  padding: 16px;
  border-radius: 8px;
  font-size: 16px;
  line-height: 1.5;
  margin-top: 20px;
}
.feedback.wrong {
  color: #704327;
  background: #faf3eb;
}
.lesson-controls {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 24px;
}
.lesson-controls .button {
  flex: 1;
  padding: 12px 16px;
  min-height: 48px;
}
.lesson .hint {
  background: none;
  border: 0;
  font-size: 14px;
  color: var(--muted);
  padding: 8px 0;
  text-decoration: underline;
  text-underline-offset: 3px;
}
.steps {
  display: flex;
  margin-top: 24px;
  gap: 10px;
  border-top: 1px solid var(--border);
  padding-top: 16px;
  justify-content: space-between;
  font-size: 13px;
  color: var(--muted);
}
.steps .active {
  color: var(--green);
  font-weight: 600;
}
.steps b {
  display: inline-block;
  border: 1px solid var(--border);
  border-radius: 50%;
  width: 23px;
  height: 23px;
  text-align: center;
  margin-right: 6px;
}
.stats {
  display: flex;
  gap: 36px;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 30px 0;
}
.counts {
  display: flex;
  gap: 42px;
  flex-shrink: 0;
}
.counts > div {
  padding-right: 42px;
  border-right: 1px solid var(--border);
}
.counts > div:last-child {
  border: 0;
  padding-right: 0;
}
.counts strong {
  font-size: 39px;
  line-height: 1.2;
  color: var(--green);
  font-weight: 600;
}
.counts p {
  font-size: 16px;
}
.subjects {
  display: flex;
  gap: 32px;
  align-items: center;
  font-size: 14px;
  color: var(--muted);
}
.subjects span {
  display: flex;
  align-items: center;
  flex-direction: column;
  gap: 4px;
}
.subjects i {
  font-style: normal;
  font-size: 26px;
  color: var(--ink);
  line-height: 1.3;
}
.outcomes .lead {
  margin-top: 14px;
}
.outcome-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  margin-top: 48px;
}
.outcome-grid article {
  padding: 0 32px;
  border-right: 1px solid var(--border);
}
.outcome-grid article:first-child {
  padding-left: 0;
}
.outcome-grid article:last-child {
  padding-right: 0;
  border: 0;
}
.outcome-icon {
  display: block;
  color: var(--green);
  font-size: 42px;
  line-height: 1;
  margin-bottom: 24px;
}
.outcome-grid p {
  font-size: 18px;
  margin: 16px 0 22px;
}
.two-routes {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr;
  gap: 32px;
  background: var(--mint);
  padding: 32px;
  margin-top: 48px;
  border-radius: 12px;
}
.two-routes h3 {
  font-size: 28px;
}
.two-routes > a {
  padding-left: 28px;
  border-left: 1px solid var(--border);
}
.two-routes b {
  font-size: 19px;
}
.two-routes p {
  font-size: 16px;
  margin-top: 8px;
}
.method {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 72px;
  align-items: center;
}
.method ol {
  list-style: none;
  padding: 0;
  margin: 32px 0 0;
  counter-reset: method;
}
.method li {
  display: flex;
  gap: 20px;
  padding: 20px 0;
  border-top: 1px solid var(--border);
}
.method li::before {
  counter-increment: method;
  content: "0" counter(method);
  font-size: 17px;
  color: var(--green);
  padding-top: 4px;
}
.method li h3 {
  font-size: 21px;
}
.method li p {
  font-size: 16px;
  margin-top: 6px;
}
.method-visual {
  background: var(--mint);
  border-radius: 12px;
  padding: 44px;
  text-align: center;
}
.method-visual .circle {
  display: block;
  margin: 28px auto;
}
.method-visual p {
  font-size: 18px;
}
.method-visual .button {
  margin-top: 24px;
}
.why {
  padding: 28px 32px;
  background: var(--mint);
  border-radius: 12px;
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 32px;
  margin-top: -46px;
  margin-bottom: 60px;
}
.why h3 {
  font-size: 23px;
}
.why p {
  font-size: 17px;
}
.catalog-heading {
  text-align: center;
}
.catalog-heading .lead {
  margin: 16px auto 32px;
}
.search {
  width: min(760px, 100%);
  margin: 0 auto 36px;
  display: block;
}
.search span {
  display: block;
  font-size: 14px;
  margin-bottom: 8px;
  color: var(--muted);
}
.search input {
  width: 100%;
  padding: 16px 20px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 18px;
}
.catalog-tools {
  display: flex;
  justify-content: space-between;
  margin-bottom: 20px;
  font-size: 14px;
  align-items: center;
}
.catalog-tools button {
  border: 0;
  background: none;
  color: var(--green);
  font-size: 14px;
  text-decoration: underline;
  text-underline-offset: 3px;
}
.catalog-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 64px;
  align-items: start;
}
.catalog-column {
  min-width: 0;
}
.catalog-group {
  border-top: 1px solid var(--border);
}
summary {
  cursor: pointer;
  list-style: none;
}
summary::-webkit-details-marker {
  display: none;
}
.catalog-group > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 22px 0;
  font-size: 22px;
  font-weight: 560;
  line-height: 1.35;
}
.catalog-group > summary small {
  color: var(--muted);
  font-size: 15px;
  font-weight: 400;
  display: block;
  margin-top: 4px;
}
.chevron {
  width: 12px;
  height: 12px;
  border: solid var(--muted);
  border-width: 0 1.5px 1.5px 0;
  transform: rotate(45deg);
  margin-right: 4px;
  flex-shrink: 0;
}
.catalog-group[open] > summary .chevron {
  transform: rotate(225deg);
}
.course-link {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid var(--border);
  padding: 13px 12px;
  font-size: 17px;
  gap: 12px;
}
.course-link:hover {
  background: var(--mint);
  color: var(--green);
}
.course-link span:last-child {
  color: var(--green);
}
[hidden] {
  display: none !important;
}
.no-results {
  padding: 32px;
  text-align: center;
  background: var(--mint);
}
.account {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 72px;
  border-top: 1px solid var(--border);
}
.account-list article {
  border-top: 1px solid var(--border);
  padding: 24px 0;
}
.account-list article:first-child {
  border-top: 0;
  padding-top: 0;
}
.account-list p {
  font-size: 18px;
  margin-top: 10px;
}
.beta {
  display: flex;
  gap: 48px;
  justify-content: space-between;
  align-items: center;
  background: var(--mint);
  padding: 40px;
  border-radius: 12px;
}
.beta h3 {
  font-size: 28px;
}
.beta p {
  font-size: 17px;
  margin-top: 12px;
  max-width: 750px;
}
.faq {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 80px;
}
.faq h2 {
  max-width: 350px;
}
.faq .lead {
  font-size: 19px;
}
.faq details {
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-bottom: 16px;
  overflow: hidden;
}
.faq summary {
  padding: 20px 24px;
  display: flex;
  justify-content: space-between;
  gap: 18px;
  font-size: 20px;
  line-height: 1.4;
}
.faq details[open] summary {
  background: var(--mint);
}
.faq details[open] .chevron {
  transform: rotate(225deg);
}
.faq details p {
  padding: 20px 24px;
  font-size: 18px;
}
.closing {
  background: var(--mint);
  padding: 64px 0;
}
.closing .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 48px;
}
.closing h2 {
  color: var(--green);
}
.closing .lead {
  font-size: 19px;
  max-width: 700px;
}
.closing .actions {
  flex-shrink: 0;
}
.footer {
  padding: 40px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.footer nav {
  display: flex;
  gap: 24px;
  font-size: 14px;
  color: var(--muted);
}
.prototype-note {
  font-size: 12px;
  text-align: center;
  padding: 12px;
  background: white;
  color: var(--muted);
  border-top: 1px solid var(--border);
}
.code {
  background: var(--mint);
  padding: 24px;
  border-radius: 8px;
  text-align: left;
  font:
    20px/1.8 ui-monospace,
    monospace;
  white-space: pre;
  overflow: auto;
  margin: 20px 0;
}
.answer-choices {
  display: flex;
  gap: 12px;
}
.answer-choices .button {
  flex: 1;
}
.bar-model {
  height: 220px;
  display: flex;
  gap: 16px;
  align-items: end;
  justify-content: center;
  border-bottom: 1px solid var(--border);
  padding: 20px 8px 0;
}
.bar-model > div {
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: end;
  align-items: center;
  width: 72px;
  gap: 6px;
}
.bar-model i {
  width: 100%;
  background: #bcd9c9;
  border-radius: 5px 5px 0 0;
  display: block;
}
.bar-model small {
  font-size: 14px;
}
.bar-control {
  display: flex;
  gap: 16px;
  align-items: center;
  margin: 16px 0;
  font-size: 16px;
}
.bar-control input {
  min-width: 0;
  width: 100%;
  accent-color: var(--green);
}
.start-grid {
  padding: 72px 0;
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 100px;
}
.start-grid h1 {
  font-size: 48px;
}
.chosen {
  padding: 32px;
  background: var(--mint);
  border-radius: 12px;
  margin-top: 32px;
}
.chosen h2 {
  font-size: 29px;
}
.chosen p {
  font-size: 16px;
  margin-top: 12px;
}
.form-panel {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 32px;
}
.form-panel h2 {
  font-size: 28px;
}
.form-panel > p {
  font-size: 15px;
  margin: 12px 0 24px;
}
.form-panel label:not(.check) {
  display: block;
  font-size: 15px;
  margin: 16px 0;
}
.form-panel input:not([type="checkbox"]) {
  display: block;
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-top: 8px;
}
.check {
  display: flex;
  gap: 12px;
  font-size: 13px;
  line-height: 1.5;
  margin: 16px 0;
}
.check input {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  accent-color: var(--green);
  margin-top: 2px;
}
.check a {
  text-decoration: underline;
}
.form-panel .primary {
  width: 100%;
  margin-top: 12px;
}
.demo-warning {
  font-size: 13px;
  color: #704327;
  background: #faf3eb;
  padding: 16px;
  border-radius: 8px;
  margin: 24px 0;
}
.next-lesson {
  max-width: 800px;
  text-align: center;
  padding: 72px 0;
  margin: auto;
}
.next-lesson h1 {
  font-size: 48px;
}
.next-lesson .chosen {
  text-align: left;
}
.next-lesson .actions {
  justify-content: center;
}
@media (max-width: 1200px) {
  .wrap {
    width: calc(100% - 80px);
  }
  h1 {
    font-size: 48px;
  }
  .hero {
    gap: 40px;
  }
  .circle {
    width: 200px;
    height: 200px;
  }
  .model-row {
    gap: 12px;
  }
  .equation {
    font-size: 28px;
  }
  .fraction {
    font-size: 28px;
  }
  .stage {
    grid-template-columns: 140px minmax(0, 1fr);
    gap: 24px;
  }
  .stage-copy {
    display: none;
  }
  .subjects {
    gap: 18px;
  }
  .counts {
    gap: 24px;
  }
  .counts > div {
    padding-right: 24px;
  }
  .method {
    gap: 40px;
  }
  .catalog-grid {
    gap: 0 40px;
  }
}
@media (max-width: 900px) {
  .wrap {
    width: calc(100% - 48px);
  }
  .nav {
    gap: 20px;
  }
  .nav a:last-child {
    display: none;
  }
  .hero {
    grid-template-columns: 1fr;
    padding-top: 32px;
    gap: 40px;
  }
  .hero h1 {
    max-width: 700px;
  }
  .hero .lead {
    max-width: 650px;
  }
  .lesson {
    max-width: 720px;
    width: 100%;
    margin: auto;
  }
  .stats {
    display: block;
  }
  .counts {
    justify-content: center;
  }
  .subjects {
    justify-content: center;
    margin-top: 24px;
    flex-wrap: wrap;
  }
  .hero-b {
    padding: 32px 24px;
  }
  .hero-b h1 {
    font-size: 49px;
  }
  .method,
  .account,
  .faq {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .method-visual {
    max-width: 680px;
  }
  .two-routes {
    grid-template-columns: 1fr 1fr;
  }
  .two-routes > h3 {
    grid-column: 1/-1;
  }
  .two-routes > a:first-of-type {
    border: 0;
    padding: 0;
  }
  .why {
    grid-template-columns: 1fr;
    gap: 14px;
  }
  .closing .wrap {
    display: block;
  }
  .closing .actions {
    margin-top: 28px;
  }
  .start-grid {
    gap: 48px;
    grid-template-columns: 1fr 1fr;
  }
  .start-grid h1 {
    font-size: 40px;
  }
}
@media (max-width: 600px) {
  .wrap {
    width: calc(100% - 44px);
  }
  body {
    font-size: 17px;
  }
  h1 {
    font-size: 39px;
    letter-spacing: -1.4px;
  }
  h2 {
    font-size: 33px;
    letter-spacing: -1px;
  }
  h3 {
    font-size: 22px;
  }
  .header {
    padding: 24px 0;
    gap: 16px;
  }
  .brand {
    font-size: 25px;
  }
  .nav {
    display: none;
  }
  .header > .button {
    font-size: 14px;
    padding: 9px 17px;
  }
  .hero {
    padding: 22px 0 40px;
    gap: 32px;
  }
  .lead {
    font-size: 18px;
    margin-top: 20px;
  }
  .actions {
    gap: 18px;
    margin-top: 26px;
  }
  .hero .actions > .button {
    width: 100%;
  }
  .hero .actions > .text-link {
    margin: auto;
  }
  .hero-b h1 {
    font-size: 39px;
  }
  .hero-b {
    padding: 24px 22px 32px;
  }
  .hero-b .lead {
    font-size: 18px;
  }
  .hero-b .actions {
    gap: 12px;
  }
  .hero-b .actions .button {
    width: 100%;
  }
  .lesson {
    padding: 20px;
  }
  .lesson-label {
    font-size: 13px;
    margin-bottom: 16px;
  }
  .lesson h3 {
    font-size: 22px;
    margin-bottom: 18px;
  }
  .model-row {
    min-height: 170px;
    gap: 16px;
  }
  .circle {
    width: 158px;
    height: 158px;
  }
  .equation {
    font-size: 23px;
  }
  .fraction {
    font-size: 25px;
    margin: 0 2px;
  }
  .fraction span:first-child {
    min-width: 24px;
  }
  .feedback {
    font-size: 14px;
    min-height: 75px;
    padding: 12px;
  }
  .lesson-controls {
    gap: 10px;
  }
  .lesson-controls .button {
    font-size: 14px;
    padding: 12px 10px;
  }
  .steps {
    font-size: 11px;
    gap: 6px;
  }
  .steps b {
    display: block;
    margin: auto auto 6px;
  }
  .steps span {
    text-align: center;
    flex: 1;
  }
  .stage-band {
    padding: 24px 0;
  }
  .stage {
    display: block;
  }
  .tabs {
    flex-direction: row;
    margin-bottom: 20px;
  }
  .tabs button {
    flex: 1;
    padding: 12px 8px;
    text-align: center;
    font-size: 14px;
    border-right: 1px solid var(--border);
    border-bottom: 0;
  }
  .counts {
    gap: 20px;
  }
  .counts strong {
    font-size: 31px;
  }
  .counts p {
    font-size: 13px;
  }
  .counts > div {
    padding-right: 20px;
  }
  .subjects {
    gap: 20px;
    font-size: 12px;
  }
  .subjects i {
    font-size: 23px;
  }
  .stats {
    padding: 24px 0;
  }
  .section {
    padding: 64px 0;
  }
  .outcome-grid {
    grid-template-columns: 1fr;
    margin-top: 32px;
    gap: 28px;
  }
  .outcome-grid article {
    border: 0;
    border-bottom: 1px solid var(--border);
    padding: 0 0 28px !important;
  }
  .outcome-grid article:last-child {
    padding-bottom: 0 !important;
  }
  .outcome-icon {
    font-size: 34px;
    margin-bottom: 16px;
  }
  .outcome-grid p {
    font-size: 17px;
  }
  .two-routes {
    grid-template-columns: 1fr;
    padding: 24px;
    gap: 24px;
    margin-top: 32px;
  }
  .two-routes > h3 {
    grid-column: auto;
    font-size: 26px;
  }
  .two-routes > a {
    border: 0;
    border-top: 1px solid var(--border) !important;
    padding: 20px 0 0 !important;
  }
  .method {
    gap: 32px;
  }
  .method li {
    gap: 16px;
  }
  .method-visual {
    padding: 28px 20px;
  }
  .method-visual .circle {
    width: 220px;
    height: 220px;
  }
  .why {
    padding: 24px;
    margin-top: -20px;
    margin-bottom: 0;
  }
  .catalog-heading {
    text-align: left;
  }
  .search {
    margin-bottom: 24px;
  }
  .search input {
    font-size: 16px;
  }
  .catalog-tools {
    gap: 16px;
    align-items: start;
  }
  .catalog-grid {
    grid-template-columns: 1fr;
  }
  .catalog-group > summary {
    font-size: 20px;
    padding: 20px 0;
  }
  .course-link {
    font-size: 16px;
    padding: 13px 6px;
  }
  .catalog-group > summary small {
    font-size: 13px;
  }
  .account {
    gap: 28px;
  }
  .account-list h3 {
    font-size: 22px;
  }
  .account-list p {
    font-size: 17px;
  }
  .beta {
    display: block;
    padding: 26px;
  }
  .beta h3 {
    font-size: 26px;
  }
  .beta .button {
    margin-top: 24px;
    width: 100%;
  }
  .faq {
    gap: 32px;
  }
  .faq summary {
    font-size: 18px;
    padding: 18px;
  }
  .faq details p {
    font-size: 16px;
    padding: 18px;
  }
  .closing {
    padding: 48px 0;
  }
  .closing .actions {
    display: grid;
  }
  .footer {
    display: block;
    padding: 28px 0;
  }
  .footer nav {
    flex-wrap: wrap;
    gap: 16px;
    margin-top: 24px;
  }
  .prototype-note {
    padding: 12px 22px;
  }
  .code {
    font-size: 15px;
    padding: 16px;
  }
  .answer-choices {
    gap: 8px;
  }
  .answer-choices .button {
    font-size: 14px;
    padding: 12px 8px;
  }
  .start-grid {
    grid-template-columns: 1fr;
    padding: 40px 0;
    gap: 32px;
  }
  .start-grid h1,
  .next-lesson h1 {
    font-size: 36px;
  }
  .form-panel {
    padding: 24px;
  }
  .chosen {
    padding: 24px;
  }
  .next-lesson {
    padding: 48px 0;
  }
  .next-lesson .actions .button {
    width: 100%;
  }
}
@media (max-width: 360px) {
  .model-row {
    gap: 10px;
  }
  .circle {
    width: 132px;
    height: 132px;
  }
  .fraction {
    font-size: 23px;
  }
  .equation {
    font-size: 20px;
  }
  .counts {
    gap: 15px;
  }
  .counts > div {
    padding-right: 15px;
  }
  .counts strong {
    font-size: 28px;
  }
  .button {
    padding: 12px 18px;
  }
  .lesson-controls .button {
    flex-basis: 100%;
  }
  .method-visual .circle {
    width: 200px;
    height: 200px;
  }
}
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  .circle path {
    transition: none;
  }
}
.bar-model i[data-height="0"] {
  height: 0px;
}
.bar-model i[data-height="1"] {
  height: 12.5px;
}
.bar-model i[data-height="2"] {
  height: 25px;
}
.bar-model i[data-height="3"] {
  height: 37.5px;
}
.bar-model i[data-height="4"] {
  height: 50px;
}
.bar-model i[data-height="5"] {
  height: 62.5px;
}
.bar-model i[data-height="6"] {
  height: 75px;
}
.bar-model i[data-height="7"] {
  height: 87.5px;
}
.bar-model i[data-height="8"] {
  height: 100px;
}
.bar-model i[data-height="9"] {
  height: 112.5px;
}
.bar-model i[data-height="10"] {
  height: 125px;
}
.bar-model i[data-height="11"] {
  height: 137.5px;
}
.bar-model i[data-height="12"] {
  height: 150px;
}
.start-grid h1 {
  margin-top: 32px;
}
/* B keeps the entire teaching stage legible before the catalogue. */
.subjects svg {
  width: 32px;
  height: 34px;
  color: var(--ink);
}
.outcome-icon svg {
  width: 44px;
  height: 44px;
}
@media(min-width:1201px){.hero h1{font-size:68px;letter-spacing:-2.5px}.hero .lead{font-size:24px}.hero .actions .button,.hero .text-link{font-size:18px}}
@media (max-width: 600px) {
  .hero {
    grid-template-columns: minmax(0, 1fr);
  }
  .hero > div {
    min-width: 0;
  }
  .hero h1 {
    font-size: clamp(30px, 9vw, 39px);
    overflow-wrap: anywhere;
  }
}
@media (min-width: 901px) {
  .hero-b {
    padding-top: 28px;
    padding-bottom: 28px;
  }
  .hero-b h1 {
    font-size: 56px;
  }
  .hero-b .lead {
    font-size: 20px;
    margin-top: 20px;
    margin-bottom: 20px;
  }
  .hero-b .actions {
    margin-top: 24px;
  }
  .stage-band {
    padding: 28px 0;
  }
  .stage #lesson {
    display: grid;
    grid-template-columns: minmax(190px, 1fr) minmax(170px, 1fr);
    gap: 14px 20px;
    padding: 24px;
  }
  .stage #lesson .lesson-label,
  .stage #lesson h3,
  .stage #lesson .steps {
    grid-column: 1/-1;
    margin: 0;
  }
  .stage #lesson h3 {
    font-size: 24px;
  }
  .stage #lesson .model-row {
    grid-column: 1;
    grid-row: 3/5;
    flex-direction: column;
    gap: 8px;
    min-height: 0;
  }
  .stage #lesson .circle {
    width: 164px;
    height: 164px;
  }
  .stage #lesson .fraction {
    font-size: 27px;
  }
  .stage #lesson .feedback {
    grid-column: 2;
    grid-row: 3;
    margin: 0;
    min-height: 90px;
  }
  .stage #lesson .lesson-controls {
    grid-column: 2;
    grid-row: 4;
    display: grid;
    margin: 0;
    gap: 10px;
    align-content: start;
  }
  .stage #lesson #practice-controls {
    grid-column: 1/-1;
    grid-row: auto;
    display: flex;
  }
  .stage #lesson .hint {
    grid-column: 1/-1;
  }
  .stage #lesson .steps {
    padding-top: 12px;
  }
}