/* Learning layouts favour readable text, clear groups and untimed practice. */
:root {
  --ink: #302650;
  --purple: #514297;
  --lime: #d7ee73;
  --paper: #fffcf5;
  --line: #d7cfe4;
  --muted: #5e566e;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 24px; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: 'Avenir Next', 'Segoe UI', Arial, sans-serif; font-size: 18px; line-height: 1.7; }
a { color: inherit; text-underline-offset: .2em; }
button, input, select { font: inherit; }
button { cursor: pointer; }
button:disabled { cursor: default; opacity: .6; }
[hidden], [data-level-hidden="true"] { display: none !important; }
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, summary:focus-visible, [tabindex]:focus-visible { outline: 3px solid #514297; outline-offset: 4px; }
.wrap { max-width: 1340px; padding: 0 40px; margin: auto; }
.skip { position: absolute; top: -100px; left: 12px; background: var(--purple); color: white; padding: 12px; z-index: 3; }
.skip:focus { top: 8px; }
header { min-height: 112px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: flex; align-items: center; gap: 15px; text-decoration: none; font-weight: 600; font-size: 20px; line-height: 1.4; }
.mark { display: grid; place-items: center; flex-shrink: 0; background: var(--purple); color: white; width: 48px; height: 48px; border-radius: 13px; font-family: Georgia, serif; font-size: 32px; font-style: italic; letter-spacing: -5px; padding-right: 5px; }
.brand small { display: block; font-size: 13px; font-weight: 400; letter-spacing: 0; margin-top: 6px; }
nav { display: flex; flex-wrap: wrap; gap: 12px 24px; font-size: 16px; }
nav a { display: inline-flex; align-items: center; min-height: 44px; }
.intro { padding: 44px 0 48px; background: var(--purple); color: white; }
.eyebrow { font-size: 15px; letter-spacing: 0; font-weight: 600; margin: 0 0 16px; }
h1 { font-size: clamp(42px, 5vw, 64px); line-height: 1.15; letter-spacing: -1.5px; margin: 0; font-weight: 600; }
h1 span { color: var(--lime); }
.intro p:not(.eyebrow) { font-size: 20px; color: #f5f1ff; line-height: 1.7; margin: 22px 0; max-width: 66ch; }
.intro-notes { display: flex; flex-wrap: wrap; gap: 12px 25px; font-size: 16px; color: #f0eaff; }
.catalog { padding: 36px 0; }
.catalog-heading { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 20px; margin-bottom: 24px; }
.catalog-heading h2 { font-size: 25px; font-weight: 600; line-height: 1.4; margin: 0; }
.filters { display: flex; flex-wrap: wrap; background: #f0ebf8; border-radius: 28px; padding: 5px; gap: 4px; }
.filters button { min-height: 44px; border: 0; background: none; border-radius: 24px; padding: 8px 18px; font-size: 16px; color: var(--purple); }
.filters button[aria-pressed=true] { background: var(--purple); color: white; }
.tool-cards { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 14px; }
.tool-card { display: flex; flex-direction: column; border: 2px solid var(--line); border-radius: 14px; padding: 18px; text-decoration: none; position: relative; background: #fffefa; transition: background .15s; min-height: 156px; }
.tool-card:hover { background: #f0ebf8; }
.tool-card[aria-current] { border-color: var(--purple); background: #f0ebf8; }
.card-icon { font-family: 'Avenir Next', 'Segoe UI', Arial, sans-serif; font-size: 27px; line-height: 1.3; display: block; color: #665098; }
.tool-card[data-subject=Physics] .card-icon { color: #986681; }
.tool-card small { font-size: 14px; letter-spacing: 0; margin: 12px 0 8px; color: var(--muted); line-height: 1.5; }
.tool-card strong { font-size: 17px; line-height: 1.4; font-weight: 600; overflow-wrap: anywhere; }
.card-description { display: none; }
.explorer { border: 1px solid var(--line); border-radius: 20px; background: #fffefa; overflow: hidden; scroll-margin-top: 24px; }
.explorer-heading { display: flex; align-items: center; justify-content: space-between; gap: 30px; background: #ede7f7; padding: 32px; }
.explorer-heading .eyebrow { font-size: 15px; margin-bottom: 10px; }
.explorer-heading h2 { font-size: 34px; line-height: 1.3; letter-spacing: -.6px; font-weight: 600; margin: 0; }
.explorer-heading p:not(.eyebrow) { font-size: 18px; color: var(--muted); margin: 15px 0 0; max-width: 65ch; }
#tool-title:focus { outline: none; }
.outline-button { min-height: 46px; border: 1px solid #a793c7; border-radius: 8px; background: #fffdf8; color: var(--ink); padding: 10px 16px; font-size: 16px; line-height: 1.5; }
.outline-button:hover { background: #f1ebf8; }
.model-grid { display: grid; grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr); gap: 40px; padding: 32px; }
.mini-heading { font-size: 16px; font-weight: 600; letter-spacing: 0; line-height: 1.5; margin: 0 0 22px; color: #5d4977; }
.control { margin-bottom: 24px; }
.control label { display: flex; justify-content: space-between; gap: 12px; align-items: flex-start; font-size: 18px; font-weight: 500; line-height: 1.5; margin-bottom: 8px; }
.control output { background: #eee7f8; border-radius: 6px; padding: 3px 9px; white-space: nowrap; font-size: 16px; font-weight: 600; }
.control input { display: block; width: 100%; accent-color: #65509f; cursor: pointer; min-height: 44px; }
.control select { width: 100%; min-height: 48px; font-size: 17px; padding: 12px; background: var(--paper); color: var(--ink); border: 1px solid #baacd0; border-radius: 7px; }
.think-box { background: #f0f4df; border-radius: 12px; padding: 20px; margin-top: 24px; }
.think-box strong { font-size: 18px; font-weight: 600; }
.think-box p { font-size: 18px; color: #50573e; margin: 10px 0 0; line-height: 1.7; }
.visual-panel { min-width: 0; }
#visual { overflow-x: auto; border-radius: 12px; }
.visual-panel svg { display: block; width: 100%; min-width: 440px; height: auto; border: 1px solid #ded5e8; background: #fffdf9; border-radius: 12px; }
.visual-panel svg text { font-family: 'Avenir Next', 'Segoe UI', Arial, sans-serif; font-size: 18px; fill: #443352; }
.visual-panel svg .small-label { font-size: 16px; }
.visual-panel svg .big-label { font-size: 29px; font-family: 'Avenir Next', 'Segoe UI', Arial, sans-serif; }
.result { font-family: 'Avenir Next', 'Segoe UI', Arial, sans-serif; font-size: 27px; font-weight: 600; line-height: 1.55; background: #f1ecf8; padding: 20px; border-radius: 10px; margin-top: 20px; color: #514297; overflow-wrap: anywhere; }
.caption { font-size: 16px; color: var(--muted); line-height: 1.7; margin: 15px 0 0; max-width: 70ch; }
.explanation-grid { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, .8fr); gap: 36px; padding: 32px; border-top: 1px solid var(--line); }
.steps { list-style: decimal; margin: 0; padding: 0 0 0 1.8em; display: grid; gap: 20px; }
.steps li { font-size: 18px; line-height: 1.75; padding-left: 8px; max-width: 66ch; }
.steps li::marker { color: #514297; font-size: 18px; font-weight: 600; }
.explanation-grid.without-mixup { grid-template-columns: minmax(0, 1fr); }
.mistake[hidden] { display: none; }
.mistake { border-radius: 12px; background: #faf0df; padding: 24px; }
.mistake>span { color: #987023; font-size: 27px; }
.mistake h3 { font-size: 23px; line-height: 1.4; font-weight: 600; margin: 8px 0 14px; }
.mistake p { font-size: 18px; line-height: 1.75; color: #64513e; margin: 0; max-width: 60ch; }
.practice { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, .8fr); gap: 36px; background: #f5f1e9; padding: 32px; }
.practice h3 { font-size: 27px; line-height: 1.4; font-weight: 600; margin: 0 0 12px; }
.practice .mini-heading { margin-bottom: 12px; }
.practice-note { font-size: 17px; color: var(--muted); margin: 0 0 15px; max-width: 62ch; }
.question { font-size: 21px; line-height: 1.7; margin: 18px 0 24px; font-weight: 500; max-width: 60ch; }
.practice form label { font-size: 18px; font-weight: 500; display: block; margin-bottom: 9px; }
.answer-row { display: flex; flex-wrap: wrap; gap: 12px; }
.answer-row input { min-width: 0; width: 160px; min-height: 48px; font-size: 20px; padding: 12px; border: 1px solid #b09dc7; border-radius: 8px; color: var(--ink); background: #fffdf9; }
.button { background: var(--purple); color: white; min-height: 48px; border: 0; border-radius: 8px; padding: 12px 18px; font-size: 16px; font-weight: 500; line-height: 1.5; }
.button:hover { background: #6452ae; }
.text-button { min-height: 44px; border: 0; background: none; color: var(--purple); font-size: 16px; text-decoration: underline; text-underline-offset: 4px; padding: 10px 0; margin-top: 14px; text-align: left; }
.feedback { padding: 16px; border-radius: 8px; background: #f5dfc4; font-size: 18px; line-height: 1.7; margin: 18px 0 0; }
.feedback.correct { background: #e4edbd; }
.practice-help { background: #fffdf8; padding: 24px; border-radius: 12px; }
.practice-help h3 { font-family: 'Avenir Next', 'Segoe UI', Arial, sans-serif; font-size: 25px; font-weight: 600; margin-bottom: 20px; }
.hint-text { background: #edf2d5; padding: 16px; border-radius: 8px; font-size: 18px; line-height: 1.7; }
.practice-help details { border-top: 1px solid var(--line); margin-top: 24px; padding-top: 18px; }
summary { display: flex; align-items: center; justify-content: space-between; gap: 16px; min-height: 44px; cursor: pointer; font-size: 17px; line-height: 1.5; font-weight: 500; list-style: none; }
summary::-webkit-details-marker { display: none; }
summary span { font-size: 24px; line-height: 1; flex-shrink: 0; }
details[open] summary span { transform: rotate(45deg); }
#worked-steps { font-size: 18px; line-height: 1.75; padding-left: 24px; }
#worked-steps li { margin-bottom: 16px; padding-left: 4px; }
.tool-bottom { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 20px; padding: 24px 32px; font-size: 16px; }
.tool-bottom a { display: inline-flex; align-items: center; min-height: 44px; }
.tool-bottom p { font-size: 16px; color: var(--muted); margin: 0; max-width: 48ch; }
.teacher-note { padding: 30px 0; }
.teacher-note details { border: 1px solid var(--line); border-radius: 12px; padding: 20px 24px; }
.teacher-note p { font-size: 17px; color: var(--muted); line-height: 1.75; max-width: 80ch; }
footer { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 20px; border-top: 1px solid var(--line); padding-top: 24px !important; padding-bottom: 28px !important; font-size: 15px; }
footer a { display: inline-flex; align-items: center; min-height: 44px; }
.foundation { padding: 24px 32px; border-bottom: 1px solid var(--line); background: #f7f4fc; }
.foundation strong { font-size: 18px; font-weight: 600; color: #59417a; }
.foundation p { font-size: 18px; color: #5e526f; line-height: 1.75; max-width: 68ch; margin: 12px 0 0; }
/* These controls also support shorter, one-step-at-a-time lesson views. */
.reading-controls, .learning-mode { display: flex; align-items: center; flex-wrap: wrap; gap: 12px; }
.reading-controls { margin: 24px 0; padding: 20px 24px; border: 1px solid var(--line); border-radius: 12px; background: #fffefa; }
.reading-controls label, .learning-mode label, .learning-mode strong { font-size: 17px; font-weight: 600; }
.reading-controls button, .learning-mode button, .step-navigation button { min-height: 46px; border: 1px solid #b3a0cb; border-radius: 8px; background: #fffdf8; color: var(--ink); font-size: 16px; padding: 10px 16px; }
.reading-controls button[aria-pressed=true], .learning-mode button[aria-pressed=true] { background: var(--purple); border-color: var(--purple); color: white; }
.learning-mode { padding: 20px 32px; background: #f7f4fc; border-bottom: 1px solid var(--line); }
.learning-mode p { margin: 0; font-size: 17px; max-width: 64ch; }
.concept-lines { display: grid; gap: 12px; margin: 16px 0 0; padding-left: 24px; max-width: 68ch; }
.concept-lines li { font-size: 18px; line-height: 1.7; padding-left: 3px; }
.guided-steps { padding: 22px; border-radius: 12px; border: 1px solid var(--line); background: #f7f4fc; }
.guided-steps p, .guided-steps li { font-size: 18px; line-height: 1.75; }
.step-navigation { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; margin-top: 20px; }
.step-progress { font-size: 16px; font-weight: 600; color: var(--purple); margin: 0 0 12px; }
.terms-list { font-size: 17px; line-height: 1.75; max-width: 65ch; }
.terms-list dt { font-weight: 600; margin-top: 16px; }
.terms-list dd { margin: 6px 0 0; }
.terms-list li { margin-bottom: 12px; }
@media (max-width: 1050px) {
  .tool-cards { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .wrap { padding-left: 28px; padding-right: 28px; }
  .model-grid, .explanation-grid, .practice { gap: 28px; padding-left: 26px; padding-right: 26px; }
  .model-grid { grid-template-columns: minmax(0, 1fr); }
  .visual-panel { max-width: 720px; width: 100%; }
  .explanation-grid, .practice { grid-template-columns: minmax(0, 1fr); }
}
@media (max-width: 760px) {
  .wrap { padding-left: 20px; padding-right: 20px; }
  header { min-height: 100px; gap: 15px; flex-wrap: wrap; padding-top: 18px !important; padding-bottom: 18px !important; }
  .brand { font-size: 18px; gap: 12px; }
  .brand small { font-size: 12px; }
  .mark { width: 42px; height: 42px; font-size: 28px; border-radius: 11px; }
  nav { font-size: 15px; gap: 12px 20px; }
  .intro { padding: 32px 0 36px; }
  .eyebrow { font-size: 14px; }
  h1 { font-size: 42px; letter-spacing: -.8px; }
  .intro p:not(.eyebrow) { font-size: 18px; }
  .intro-notes { font-size: 16px; gap: 10px 16px; }
  .catalog { padding: 28px 0; }
  .catalog-heading h2 { font-size: 24px; }
  .tool-cards { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
  .tool-card { padding: 15px; min-height: 152px; }
  .tool-card strong { font-size: 16px; }
  .tool-card small { font-size: 13px; }
  .card-icon { font-size: 25px; }
  .explorer { border-radius: 15px; }
  .explorer-heading { padding: 24px 20px; display: block; }
  .explorer-heading h2 { font-size: 30px; letter-spacing: -.4px; }
  .explorer-heading .eyebrow { font-size: 14px; }
  .explorer-heading p:not(.eyebrow) { font-size: 18px; }
  .explorer-heading .outline-button { margin-top: 20px; }
  .model-grid, .explanation-grid, .practice { gap: 28px; padding: 24px 20px; }
  .result { font-size: 25px; padding: 18px; }
  .steps li { padding-left: 6px; }
  .mistake { padding: 22px; }
  .practice h3 { font-size: 26px; }
  .question { font-size: 20px; }
  .answer-row input { width: 130px; }
  .practice-help { padding: 22px; }
  .tool-bottom { padding: 22px 20px; }
  .teacher-note { padding: 24px 0; }
  .teacher-note details { padding: 20px; }
  .foundation, .learning-mode { padding: 24px 20px; }
  .reading-controls { padding: 20px; }
  .guided-steps { padding: 18px; }
  #visual svg { min-width: 440px; }
}
@media (max-width: 370px) {
  .wrap { padding-left: 14px; padding-right: 14px; }
  .tool-card { padding: 12px; }
  .tool-card small { font-size: 13px; }
  .brand { font-size: 17px; }
  h1 { font-size: 38px; }
  .model-grid, .explanation-grid, .practice, .foundation, .learning-mode { padding-left: 16px; padding-right: 16px; }
  .answer-row { flex-direction: column; align-items: stretch; }
  .answer-row input { width: 100%; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}

.learning-mode-option { display: inline-flex; align-items: center; gap: 10px; min-height: 48px; padding: 10px 14px; border: 1px solid #b3a0cb; border-radius: 8px; background: #fffefa; cursor: pointer; font-size: 17px; line-height: 1.5; }
.learning-mode-option:has(input:checked) { background: #eee7f8; border-color: var(--purple); }
.learning-mode-option input { width: 22px; height: 22px; margin: 0; accent-color: var(--purple); flex-shrink: 0; }
.learning-mode-note { flex-basis: 100%; color: var(--muted); font-size: 17px; line-height: 1.7; }
.focus-toggle { min-height: 46px; border: 1px solid #b3a0cb; border-radius: 8px; background: #fffdf8; color: var(--ink); font-size: 16px; padding: 10px 16px; }
.focus-toggle[aria-pressed=true] { background: var(--purple); border-color: var(--purple); color: white; }
body.focus-mode .intro, body.focus-mode .catalog, body.focus-mode .teacher-note, body.focus-mode .think-box, body.focus-mode .mistake { display: none; }
body.focus-mode .explorer { margin-top: 24px; }
body.focus-mode .explanation-grid { grid-template-columns: minmax(0, 1fr); }
.diagram-scroll-note { display: none; }
@media (max-width: 760px) { .diagram-scroll-note { display: block; font-size: 16px; line-height: 1.7; color: var(--muted); margin: 0 0 12px; } }

.balance-actions { margin: 20px 0 28px; padding: 20px; border-radius: 12px; background: #f3eef9; display: flex; flex-direction: column; gap: 14px; }
.balance-actions p { margin: 0; font-size: 18px; line-height: 1.7; }
.balance-actions button { white-space: normal; line-height: 1.5; min-height: 48px; }
.balance-actions[hidden] { display: none; }

.learning-routes { padding: 24px; border: 1px solid var(--line); border-radius: 14px; background: #f3f5e8; margin: 0 0 28px; }
.learning-routes h2 { font-size: 24px; line-height: 1.4; margin: 0 0 12px; }
.learning-routes p { margin: 0 0 16px; max-width: 68ch; }
.learning-routes label { display: block; font-weight: 600; margin-bottom: 10px; }
.learning-routes select { width: 100%; max-width: 560px; font: inherit; min-height: 48px; padding: 12px; border: 1px solid #baacd0; border-radius: 8px; background: #fffefa; color: var(--ink); }
#route-preview { margin-top: 20px; }
#route-steps { margin: 16px 0 22px; padding-left: 26px; }
#route-steps li { margin: 10px 0; padding-left: 6px; }
#route-steps a { display: inline-block; min-height: 44px; padding: 6px 0; }
#route-start { display: inline-flex; white-space: normal; text-decoration: none; }
#route-warmups, #tool-warmups { display: flex; flex-direction: column; align-items: flex-start; gap: 10px; margin: 20px 0; }
#route-warmups a, #tool-warmups a { min-height: 44px; padding: 6px 0; }
.route-navigation { padding: 20px 32px; background: #f3f5e8; display: flex; align-items: center; flex-wrap: wrap; gap: 14px 24px; }
.route-navigation strong { flex-basis: 100%; font-size: 18px; }
.route-navigation a { font-size: 17px; overflow-wrap: anywhere; }
.ready-next { padding: 28px 32px; border-top: 1px solid var(--line); background: #f6f4fb; }
.ready-next h3 { font-size: 23px; margin: 0 0 14px; }
.ready-next p { max-width: 65ch; margin: 10px 0; }
#ready-check { font-weight: 600; }
#suggested-next { display: inline-flex; text-decoration: none; white-space: normal; margin-top: 12px; }
@media(max-width:760px) { .learning-routes, .ready-next, .route-navigation { padding: 20px; } }
.model-points { width: 100%; margin-top: 24px; border-collapse: collapse; font-size: 18px; }
.model-points caption { text-align: left; font-weight: 600; margin-bottom: 10px; }
.model-points th, .model-points td { padding: 10px 14px; border: 1px solid var(--line); text-align: center; }
.model-points th { background: #f0ebf8; }

/* Topic drawings and personal progress: colour always has a written label. */
.card-icon{display:block;line-height:1;height:34px}
.card-icon svg{display:block;width:32px;height:32px}
.progress-overview{margin:24px 0;color:#4e4265;font-size:17px;max-width:74ch}
.progress-overview p{margin:6px 0}
.progress-label{display:inline-block;align-self:flex-start;max-width:100%;padding:3px 10px;border:1px solid #cfc6db;border-radius:100px;background:#f6f2fa;color:#554964;font-size:16px;font-weight:650;line-height:1.6}
.tool-card .progress-label{margin-top:auto}
.tool-card strong{margin-bottom:14px}
.tool-card[data-progress=viewed]{background:#f5f0fb}
.tool-card[data-progress=started]{background:#fff6e9}
.tool-card[data-progress=finished]{background:#eef7e9}
[data-progress=viewed] .progress-label,.progress-label[data-progress=viewed]{background:#e9def8;border-color:#bba4d6;color:#4d3473}
[data-progress=started] .progress-label,.progress-label[data-progress=started]{background:#fce7bc;border-color:#d7b263;color:#664409}
[data-progress=finished] .progress-label,.progress-label[data-progress=finished]{background:#dbeed0;border-color:#a3c48b;color:#315424}
.tool-card[aria-current=true]{border-color:#665098;box-shadow:0 0 0 1px #665098}
.learning-progress{margin:26px 0;padding:20px;border:1px solid #d7cfe4;border-radius:18px;background:#fffefa}
.learning-progress p{margin:0 0 12px}
.progress-actions{display:flex;align-items:center;gap:12px;flex-wrap:wrap}

.question-level{display:inline-block;background:#e9e1f3;border:1px solid #b9a7d0;border-radius:10px;padding:6px 12px;font-size:16px;font-weight:600;margin:0 0 12px}
.practice-unavailable{padding:18px;border:1px solid #d7cfe4;border-radius:12px;background:#fffdf8}
.practice-unavailable p{margin:0 0 16px;max-width:60ch}

.particle-playback{margin:16px 0;padding:16px;border:1px solid var(--line);border-radius:12px;background:#f6f3fa}
.particle-playback p{margin:8px 0 0;max-width:60ch;font-size:16px}
.particle-playback [role=status]{font-size:17px}

#visual svg[data-particle-layout=compact]{min-width:0;width:100%}
.particle-playback [data-motion-note]{margin:0 0 14px;font-size:18px;font-weight:600}

#sketch-playback label{display:block;margin:16px 0 8px;font-size:18px;font-weight:600}
#sketch-time{width:100%;min-height:44px}

/* Each lesson has its own document. Browsing cards belong to the catalogue. */
.breadcrumbs{margin:12px 0 22px;font-size:16px;gap:8px 12px;color:var(--muted);overflow-wrap:anywhere}
.breadcrumbs a{min-height:36px}
.lesson-page .reading-controls{margin:0 0 22px}
.lesson-page .explorer-heading h1{font-size:34px;line-height:1.3;letter-spacing:-.6px;margin:0}
.lesson-page .teacher-note{padding-top:32px}
.catalog-page .tool-cards{grid-template-columns:repeat(3,minmax(0,1fr))}
.catalog-page .card-description{display:block;font-size:16px;line-height:1.65;color:var(--muted);margin:0 0 18px}
.catalog-page .tool-card strong{font-size:21px;overflow-wrap:normal}
.catalog-page .tool-card{padding:24px;min-height:280px}
.noscript-note{padding:18px;border:1px solid var(--line);border-radius:12px;background:#f0f4df}
#activity-label{margin:0 0 18px;font-weight:600}
@media(max-width:1050px){.catalog-page .tool-cards{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:760px){.catalog-page .tool-cards{grid-template-columns:minmax(0,1fr)}.catalog-page .tool-card{min-height:0}.lesson-page .explorer-heading h1{font-size:29px}.breadcrumbs{font-size:15px}.reading-controls span{font-size:16px}}

.diagram-notes{margin:20px 0;padding:16px;border:1px solid var(--line);border-radius:10px;background:#f6f3fa}
.diagram-notes p{font-size:17px;line-height:1.75;color:var(--muted);max-width:65ch}

.lesson-goal{margin:0 0 24px;max-width:65ch;font-size:19px;line-height:1.7;color:var(--ink)}

/* Shared logo extracted from the approved Facebook advert. */
.brand-logo{display:block;flex:0 0 60px;width:60px;height:60px;object-fit:contain}
.brand{font-family:'Arial Rounded MT Bold','Avenir Next','Segoe UI',sans-serif}
.brand small{font-family:'Avenir Next','Segoe UI',Arial,sans-serif}
@media(max-width:760px){.brand-logo{flex-basis:48px;width:48px;height:48px}}