:root {
  color-scheme: light;
  --paper: #f4efe5;
  --paper-strong: #ebe2d2;
  --ink: #172622;
  --muted: #5d6964;
  --line: #cfc4b3;
  --forest: #173e35;
  --forest-2: #245e50;
  --teal: #71a899;
  --lime: #dbe3a3;
  --amber: #df9d49;
  --cream: #fffaf0;
  --white: #fffdf8;
  --shadow: 0 22px 60px rgba(35, 49, 42, .1);
  --radius: 22px;
  --content: min(1180px, calc(100vw - 40px));
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 96px;
  overflow-x: clip;
}

body {
  margin: 0;
  min-width: 320px;
  overflow-x: clip;
  background:
    radial-gradient(circle at 8% 8%, rgba(219, 227, 163, .28), transparent 30rem),
    var(--paper);
  color: var(--ink);
  font-family: ui-sans-serif, -apple-system, BlinkMacSystemFont, "SF Arabic", "Noto Sans Arabic", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.8;
}

button,
input {
  font: inherit;
}

a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

:focus-visible {
  outline: 3px solid var(--amber);
  outline-offset: 4px;
}

[hidden] {
  display: none !important;
}

.skip-link {
  position: fixed;
  inset-block-start: 12px;
  inset-inline-start: 12px;
  z-index: 100;
  padding: 10px 16px;
  border-radius: 10px;
  background: var(--ink);
  color: white;
  transform: translateY(-150%);
}

.skip-link:focus {
  transform: none;
}

.site-header {
  position: sticky;
  inset-block-start: 0;
  z-index: 50;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 28px;
  width: 100%;
  min-height: 76px;
  padding: 10px max(20px, calc((100vw - 1240px) / 2));
  border-block-end: 1px solid rgba(23, 38, 34, .12);
  background: rgba(244, 239, 229, .94);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  width: max-content;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 50% 50% 50% 12px;
  background: var(--forest);
  color: var(--lime);
  font-size: 23px;
  font-weight: 800;
}

.brand strong,
.brand small {
  display: block;
  line-height: 1.25;
}

.brand small {
  color: var(--muted);
  font-size: 12px;
}

.primary-nav {
  display: flex;
  gap: 8px;
  padding: 5px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 253, 248, .74);
}

.primary-nav a {
  padding: 7px 14px;
  border-radius: 999px;
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
}

.primary-nav a:hover,
.primary-nav a[aria-current="true"],
.primary-nav a[aria-current="page"] {
  background: var(--forest);
  color: white;
}

.search-toggle {
  justify-self: end;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 15px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
}

.search-toggle:hover {
  background: var(--white);
}

.search-panel {
  position: fixed;
  inset-block-start: 86px;
  inset-inline: max(20px, calc((100vw - 900px) / 2));
  z-index: 60;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow);
}

.search-panel > label {
  display: block;
  margin-block-end: 12px;
  font-weight: 800;
}

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

.search-row input {
  min-width: 0;
  padding: 13px 16px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--cream);
  color: var(--ink);
}

.search-row button {
  padding: 8px 16px;
  border: 0;
  border-radius: 12px;
  background: var(--ink);
  color: white;
  cursor: pointer;
}

.search-results {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
  max-height: min(55vh, 480px);
  margin-block-start: 14px;
  overflow-y: auto;
}

.search-results a {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 11px 13px;
  border-radius: 10px;
  background: var(--paper);
  text-decoration: none;
}

.search-results a:hover {
  background: var(--paper-strong);
}

.search-results small {
  color: var(--muted);
  text-align: left;
}

.study-progress {
  position: fixed;
  inset-block-start: 75px;
  inset-inline: 0;
  z-index: 55;
  height: 3px;
  background: rgba(23, 38, 34, .08);
}

.study-progress span {
  display: block;
  block-size: 100%;
  inline-size: 0;
  background: var(--amber);
  transition: inline-size .3s ease;
}

#main {
  min-height: 72vh;
  outline: none;
}

.home-hero,
.orientation-section,
.tracks-section,
.home-exam,
.lesson-hero,
.lesson-section,
.algorithm-hero,
.algorithm-setup,
.algorithm-terms,
.interactive-board,
.result-section,
.algorithm-practice,
.lesson-ending,
.simple-hero,
.exam-grid,
.source-list,
.breadcrumbs,
.print-toolbar,
.print-document {
  width: var(--content);
  margin-inline: auto;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--forest-2);
  font-size: 13px;
  font-weight: 850;
  letter-spacing: .03em;
}

.home-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(380px, .85fr);
  align-items: center;
  gap: clamp(42px, 7vw, 100px);
  min-height: min(790px, calc(100vh - 76px));
  padding-block: 84px;
}

.hero-copy {
  max-width: 720px;
}

.hero-copy h1,
.lesson-hero h1,
.algorithm-hero h1,
.simple-hero h1 {
  margin: 0;
  max-width: 1120px;
  font-size: clamp(42px, 6.5vw, 84px);
  line-height: 1.1;
  letter-spacing: -.035em;
  text-wrap: balance;
}

.hero-lead {
  max-width: 660px;
  margin: 26px 0 8px;
  color: var(--forest);
  font-size: clamp(23px, 3vw, 34px);
  font-weight: 750;
  line-height: 1.45;
}

.hero-copy > p:last-of-type {
  max-width: 680px;
  color: var(--muted);
  font-size: 18px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-block-start: 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 10px 20px;
  border: 0;
  border-radius: 12px;
  font-weight: 800;
  text-decoration: none;
  cursor: pointer;
}

.button.primary {
  background: var(--forest);
  color: white;
}

.button.secondary {
  border: 1px solid var(--forest);
  color: var(--forest);
}

.button.light {
  background: var(--cream);
  color: var(--forest);
}

.hero-board {
  position: relative;
  min-height: 450px;
  padding: 38px;
  overflow: hidden;
  border-radius: 38px 38px 38px 8px;
  background:
    linear-gradient(rgba(255,255,255,.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.035) 1px, transparent 1px),
    var(--forest);
  background-size: 28px 28px;
  color: white;
  box-shadow: var(--shadow);
}

.hero-board::after {
  content: "";
  position: absolute;
  inset-inline-end: -90px;
  inset-block-end: -90px;
  width: 240px;
  height: 240px;
  border: 36px solid rgba(219, 227, 163, .12);
  border-radius: 50%;
}

.board-question {
  max-width: 380px;
  color: var(--lime);
  font-size: clamp(27px, 4vw, 47px);
  font-weight: 850;
  line-height: 1.25;
}

.board-flow {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-block: 60px 36px;
}

.board-flow span {
  padding: 8px 13px;
  border: 1px solid rgba(255,255,255,.25);
  border-radius: 999px;
  background: rgba(255,255,255,.08);
}

.board-flow i {
  color: var(--amber);
  font-style: normal;
}

.hero-board p {
  position: relative;
  z-index: 1;
  max-width: 430px;
  color: rgba(255,255,255,.72);
}

.orientation-section,
.tracks-section {
  padding-block: 110px;
}

.orientation-section {
  display: grid;
  grid-template-columns: .7fr 1.3fr;
  gap: 72px;
  border-block-start: 1px solid var(--line);
}

.section-intro {
  max-width: 720px;
}

.section-intro h2,
.lesson-section h2,
.algorithm-setup h2,
.algorithm-terms h2,
.interactive-board h2,
.result-section h2,
.algorithm-practice h2 {
  margin: 0;
  font-size: clamp(30px, 4vw, 52px);
  line-height: 1.25;
  letter-spacing: -.02em;
  text-wrap: balance;
}

.section-intro > p:last-child {
  color: var(--muted);
}

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

.learning-route li {
  display: grid;
  grid-template-columns: 46px 1fr;
  gap: 18px;
  padding: 24px 0;
  border-block-start: 1px solid var(--line);
}

.learning-route li:last-child {
  border-block-end: 1px solid var(--line);
}

.learning-route li > span {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--forest);
  color: var(--lime);
  font-weight: 850;
}

.learning-route h3,
.learning-route p {
  margin: 0;
}

.learning-route p {
  color: var(--muted);
}

.tracks-section > .section-intro {
  margin-block-end: 42px;
}

.track-grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  grid-auto-flow: dense;
  gap: 14px;
}

.track-card {
  grid-column: span 4;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 360px;
  padding: 30px;
  border: 1px solid rgba(23, 38, 34, .12);
  border-radius: var(--radius);
  background: var(--white);
  transition: transform .25s ease, box-shadow .25s ease;
}

.track-card:nth-child(4),
.track-card:nth-child(5) {
  grid-column: span 6;
  min-height: 310px;
}

.track-card:nth-child(6) {
  grid-column: span 12;
  min-height: 280px;
  background: var(--forest);
  color: white;
}

.track-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

.track-card h3 {
  margin: 8px 0 14px;
  font-size: clamp(24px, 2.7vw, 38px);
  line-height: 1.25;
}

.track-card p {
  color: var(--muted);
}

.track-card:nth-child(6) p,
.track-card:nth-child(6) .track-footer span {
  color: rgba(255,255,255,.7);
}

.track-kicker {
  margin: 0;
  color: var(--forest-2) !important;
  font-size: 13px;
  font-weight: 800;
}

.track-card:nth-child(6) .track-kicker {
  color: var(--lime) !important;
}

.track-footer {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 20px;
  margin-block-start: 28px;
  padding-block-start: 18px;
  border-block-start: 1px solid rgba(23, 38, 34, .13);
}

.track-card:nth-child(6) .track-footer {
  border-color: rgba(255,255,255,.15);
}

.track-footer span {
  max-width: 54%;
  color: var(--muted);
  font-size: 12px;
}

.track-footer a {
  flex: none;
  font-weight: 800;
}

.home-exam {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: end;
  gap: 60px;
  margin-block: 80px 130px;
  padding: 56px;
  border-radius: 34px;
  background: var(--amber);
  color: var(--ink);
}

.home-exam h2 {
  margin: 6px 0 10px;
  font-size: clamp(30px, 4vw, 54px);
  line-height: 1.2;
}

.home-exam p:last-child {
  max-width: 700px;
}

.breadcrumbs {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  padding-block: 32px 0;
  color: var(--muted);
  font-size: 14px;
}

.lesson-hero,
.algorithm-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: end;
  gap: 50px;
  padding-block: 78px 68px;
  border-block-end: 1px solid var(--line);
}

.lesson-hero h1,
.algorithm-hero h1 {
  font-size: clamp(42px, 6vw, 76px);
}

.lesson-problem,
.algorithm-hero p:last-child {
  max-width: 820px;
  margin-block: 24px 0;
  color: var(--muted);
  font-size: 21px;
}

.lesson-term,
.algorithm-name {
  max-width: 290px;
  padding: 18px 20px;
  border-inline-start: 4px solid var(--amber);
  color: var(--forest);
  font-size: 16px;
  font-weight: 750;
}

.algorithm-name strong,
.algorithm-name span {
  display: block;
}

.algorithm-name span {
  color: var(--muted);
  font-size: 13px;
  font-weight: 500;
}

.section-nav {
  position: sticky;
  inset-block-start: 87px;
  z-index: 30;
  display: flex;
  gap: 6px;
  width: max-content;
  max-width: calc(100vw - 40px);
  margin: 22px auto 0;
  padding: 6px;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 253, 248, .94);
  box-shadow: 0 8px 26px rgba(35, 49, 42, .07);
}

.section-nav a {
  flex: none;
  padding: 7px 13px;
  border-radius: 999px;
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
}

.section-nav a:hover {
  background: var(--paper-strong);
  color: var(--ink);
}

.lesson-section,
.algorithm-setup,
.algorithm-terms,
.interactive-board,
.result-section,
.algorithm-practice {
  padding-block: 100px;
  border-block-end: 1px solid var(--line);
}

.outcome-section {
  display: grid;
  grid-template-columns: .8fr 1.2fr;
  gap: 70px;
}

.outcome-list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.outcome-list li {
  position: relative;
  padding: 17px 50px 17px 20px;
  border-radius: 13px;
  background: var(--white);
}

.outcome-list li::before {
  content: "✓";
  position: absolute;
  inset-inline-start: 18px;
  color: var(--forest-2);
  font-weight: 900;
}

.concept-list {
  max-width: 940px;
  margin: 45px auto 0;
}

.concept-list article {
  display: grid;
  grid-template-columns: 54px 1fr;
  gap: 28px;
  padding: 35px 0;
  border-block-start: 1px solid var(--line);
}

.concept-list article:last-child {
  border-block-end: 1px solid var(--line);
}

.concept-list article > span {
  color: var(--amber);
  font-size: 30px;
  font-weight: 850;
}

.concept-list h3 {
  margin: 0 0 8px;
  font-size: 27px;
}

.concept-list p {
  margin: 0;
  color: var(--muted);
}

.term-band {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(240px, 100%), 1fr));
  gap: 1px;
  margin-block-start: 38px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--line);
}

.term {
  min-width: 0;
  padding: 20px;
  background: var(--white);
}

.term span,
.term strong,
.term small {
  display: block;
}

.term span {
  color: var(--muted);
  font-size: 13px;
}

.term strong {
  margin-block-start: 7px;
  overflow-wrap: anywhere;
  color: var(--forest);
  font-size: 16px;
}

.term small {
  margin-block-start: 4px;
  color: var(--amber);
  font-weight: 800;
}

.board-links {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-block-start: 40px;
}

.board-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 120px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--white);
  text-decoration: none;
}

.board-link:hover {
  border-color: var(--forest-2);
}

.board-link.done {
  background: rgba(219, 227, 163, .35);
}

.board-link strong,
.board-link small {
  display: block;
}

.board-link small {
  margin-block-start: 6px;
  color: var(--muted);
}

.practice-section,
.algorithm-practice {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: start;
  gap: 70px;
}

.practice-prompt h2,
.algorithm-practice h2 {
  font-size: clamp(28px, 3.4vw, 44px);
  unicode-bidi: plaintext;
}

.answer-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.answer-card summary {
  padding: 20px 22px;
  color: var(--forest);
  font-weight: 850;
  cursor: pointer;
}

.answer-card > div {
  padding: 0 22px 22px;
  border-block-start: 1px solid var(--line);
}

.answer-card h3 {
  margin: 22px 0 4px;
  font-size: 15px;
}

.answer-card p {
  margin: 0;
  color: var(--muted);
}

.lesson-ending {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: start;
  gap: 30px;
  padding-block: 52px 110px;
}

.source-note {
  color: var(--muted);
  font-size: 14px;
}

.source-note summary {
  width: max-content;
  cursor: pointer;
}

.source-note ul {
  max-width: 560px;
  margin-block-start: 12px;
  padding-inline-start: 20px;
}

.source-note li {
  margin-block: 6px;
}

.source-note small {
  color: var(--muted);
}

.next-lesson {
  display: block;
  justify-self: end;
  min-width: min(100%, 420px);
  padding: 22px;
  border-radius: 15px;
  background: var(--forest);
  color: white;
  text-decoration: none;
}

.next-lesson span,
.next-lesson strong {
  display: block;
}

.next-lesson span {
  color: var(--lime);
  font-size: 13px;
}

.next-lesson strong {
  margin-block-start: 5px;
}

.algorithm-setup {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 70px;
}

.algorithm-setup > div:first-child p:last-child {
  max-width: 600px;
  color: var(--muted);
}

.input-card {
  align-self: start;
  padding: 30px;
  border-radius: 25px 25px 25px 5px;
  background: var(--forest);
  color: white;
}

.input-card > span {
  display: block;
  color: var(--lime);
  font-size: 13px;
}

.input-value {
  display: block;
  margin-block: 16px;
  overflow-wrap: anywhere;
  font-size: clamp(20px, 2.5vw, 30px);
  font-weight: 850;
}

.input-card p {
  margin: 0;
  color: rgba(255,255,255,.7);
}

.algorithm-terms h2 {
  font-size: 29px;
}

.board-header {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 30px;
  margin-block-end: 35px;
}

.static-toggle {
  flex: none;
  padding: 9px 15px;
  border: 1px solid var(--forest);
  border-radius: 10px;
  background: transparent;
  color: var(--forest);
  cursor: pointer;
}

.board-frame {
  padding: clamp(24px, 4vw, 46px);
  overflow: hidden;
  border: 1px solid rgba(255,255,255,.14);
  border-radius: 28px;
  background:
    linear-gradient(rgba(255,255,255,.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.035) 1px, transparent 1px),
    var(--forest);
  background-size: 26px 26px;
  color: white;
  box-shadow: var(--shadow);
}

.frame-heading {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 24px;
}

.frame-heading span {
  color: var(--lime);
  font-size: 13px;
}

.frame-heading h3,
.board-frame > h3 {
  margin: 0;
  font-size: clamp(25px, 3.5vw, 42px);
  line-height: 1.3;
}

.operation {
  max-width: 820px;
  margin: 18px 0 30px;
  color: rgba(255,255,255,.72);
}

.state-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 0;
}

.state-grid > div {
  min-width: 0;
  padding: 15px 17px;
  border: 1px solid rgba(255,255,255,.12);
  border-radius: 12px;
  background: rgba(255,255,255,.06);
}

.state-grid dt {
  color: var(--teal);
  font-size: 12px;
}

.state-grid dd {
  margin: 5px 0 0;
  overflow-wrap: anywhere;
  font-weight: 750;
}

.latin {
  unicode-bidi: isolate;
  font-variant-numeric: tabular-nums;
}

.step-check {
  margin-block-start: 22px;
  padding: 16px 18px;
  border-inline-start: 4px solid var(--amber);
  background: rgba(0,0,0,.13);
}

.step-check strong {
  color: var(--amber);
  font-size: 13px;
}

.step-check p {
  margin: 4px 0 0;
}

.board-controls {
  display: grid;
  grid-template-columns: auto auto 1fr auto;
  align-items: center;
  gap: 8px;
  margin-block-start: 16px;
}

.board-controls button {
  min-height: 44px;
  padding: 8px 16px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--white);
  color: var(--ink);
  font-weight: 800;
  cursor: pointer;
}

.board-controls button:disabled {
  opacity: .45;
  cursor: not-allowed;
}

.board-controls .primary-control {
  border-color: var(--forest);
  background: var(--forest);
  color: white;
}

.step-dots {
  display: flex;
  justify-content: center;
  gap: 7px;
}

.step-dots span {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--line);
}

.step-dots span.active {
  width: 24px;
  border-radius: 999px;
  background: var(--amber);
}

.all-frames {
  display: grid;
  gap: 18px;
}

.all-frames .board-frame {
  box-shadow: none;
}

.automaton {
  display: block;
  width: 100%;
  max-width: 760px;
  margin: 10px auto 30px;
  overflow: visible;
}

.automaton line,
.automaton circle {
  fill: rgba(255,255,255,.04);
  stroke: var(--teal);
  stroke-width: 2;
}

.automaton marker path {
  fill: var(--teal);
}

.automaton text {
  fill: white;
  font: 14px ui-sans-serif, sans-serif;
}

.automaton g.active circle {
  fill: var(--amber);
  stroke: var(--amber);
}

.automaton g.active text {
  fill: var(--ink);
  font-weight: 800;
}

.automaton .accept-ring {
  fill: none;
  stroke: var(--lime);
}

.table-scroll {
  max-width: 100%;
  margin-block: 10px 28px;
  overflow-x: auto;
  direction: ltr;
}

.state-table {
  width: 100%;
  min-width: 620px;
  border-collapse: collapse;
  background: rgba(255,255,255,.04);
}

.state-table th,
.state-table td {
  padding: 10px 12px;
  border: 1px solid rgba(255,255,255,.15);
  text-align: center;
}

.state-table th {
  color: var(--lime);
  font-size: 13px;
}

.state-table th:first-child,
.state-table td:first-child {
  direction: rtl;
}

.result-section {
  text-align: center;
}

.result-section h2 {
  max-width: 920px;
  margin-inline: auto;
  font-size: clamp(28px, 4vw, 48px);
}

.complete-button {
  margin-block-start: 28px;
  padding: 11px 20px;
  border: 1px solid var(--forest);
  border-radius: 12px;
  background: transparent;
  color: var(--forest);
  font-weight: 850;
  cursor: pointer;
}

.complete-button.is-complete {
  background: var(--forest);
  color: white;
}

.simple-hero {
  max-width: 1040px;
  padding-block: 100px 70px;
  text-align: center;
}

.simple-hero h1 {
  font-size: clamp(42px, 6vw, 74px);
}

.simple-hero > p:last-child {
  max-width: 720px;
  margin: 22px auto 0;
  color: var(--muted);
  font-size: 20px;
}

.exam-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  padding-block-end: 120px;
}

.exam-card {
  display: flex;
  flex-direction: column;
  min-height: 310px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.exam-meta {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  color: var(--forest-2);
  font-size: 12px;
  font-weight: 800;
}

.exam-card h2 {
  margin: 26px 0;
  font-size: 25px;
  line-height: 1.45;
  unicode-bidi: plaintext;
}

.exam-card details {
  margin-block-start: auto;
  padding-block: 14px;
  border-block: 1px solid var(--line);
}

.exam-card summary {
  font-weight: 800;
  cursor: pointer;
}

.exam-card details p {
  color: var(--muted);
}

.concept-return {
  margin-block-start: 18px;
  color: var(--forest);
  font-weight: 800;
}

.source-list {
  padding-block-end: 120px;
}

.source-list article {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 30px;
  padding: 24px 0;
  border-block-start: 1px solid var(--line);
}

.source-list article:last-child {
  border-block-end: 1px solid var(--line);
}

.source-list h2,
.source-list p {
  margin: 0;
}

.source-list h2 {
  font-size: 21px;
}

.source-list p {
  color: var(--muted);
  font-size: 13px;
}

.source-list > article > span {
  color: var(--muted);
  font-size: 14px;
}

.print-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
  margin-block: 50px 20px;
  padding: 20px 24px;
  border-radius: 16px;
  background: var(--white);
}

.print-toolbar p {
  margin: 0;
  color: var(--muted);
}

.print-document {
  margin-block-end: 100px;
  padding: 70px;
  background: white;
  box-shadow: var(--shadow);
}

.print-cover {
  min-height: 65vh;
  padding-block: 18vh 50px;
  border-block-end: 3px solid var(--forest);
}

.print-cover h1 {
  max-width: 900px;
  margin: 12px 0;
  font-size: 70px;
  line-height: 1.15;
}

.print-track {
  padding-block: 70px 30px;
  border-block-end: 2px solid var(--ink);
}

.print-track > h2 {
  font-size: 45px;
}

.print-concept {
  margin-block: 26px;
}

.print-concept h3,
.print-concept p {
  margin: 0;
}

.print-algorithm {
  margin-block-start: 55px;
  padding-block-start: 35px;
  border-block-start: 1px solid var(--line);
}

.print-algorithm > h3 {
  font-size: 31px;
}

.print-algorithm > h3 span {
  color: var(--muted);
  font-size: 16px;
}

.print-input,
.print-result,
.print-practice {
  margin-block: 18px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 10px;
}

.print-practice h3,
.print-practice h4,
.print-practice p {
  margin-block: 5px;
}

.print-practice h3,
.print-practice h4 {
  unicode-bidi: plaintext;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 30px;
  width: var(--content);
  margin-inline: auto;
  padding-block: 30px 50px;
  border-block-start: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
}

.site-footer nav {
  display: flex;
  gap: 18px;
}

.site-footer button {
  padding: 0;
  border: 0;
  background: transparent;
  color: inherit;
  text-decoration: underline;
  cursor: pointer;
}

@media (max-width: 980px) {
  .site-header {
    grid-template-columns: 1fr auto;
    backdrop-filter: none;
  }

  .primary-nav {
    position: fixed;
    inset-inline: 14px;
    inset-block-end: 12px;
    z-index: 80;
    justify-content: center;
    box-shadow: var(--shadow);
  }

  .search-toggle {
    grid-column: 2;
  }

  .home-hero {
    grid-template-columns: 1fr;
    padding-block: 70px;
  }

  .hero-board {
    min-height: 390px;
  }

  .orientation-section {
    grid-template-columns: 1fr;
    gap: 30px;
  }

  .track-card {
    grid-column: span 6;
  }

  .track-card:nth-child(3),
  .track-card:nth-child(6) {
    grid-column: span 12;
  }

  .track-card:nth-child(4),
  .track-card:nth-child(5) {
    grid-column: span 6;
  }

  .lesson-hero,
  .algorithm-hero {
    grid-template-columns: 1fr;
  }

  .lesson-term,
  .algorithm-name {
    max-width: 100%;
  }

  .outcome-section,
  .practice-section,
  .algorithm-practice,
  .algorithm-setup {
    grid-template-columns: 1fr;
    gap: 38px;
  }

  .print-document {
    padding: 40px;
  }
}

@media (max-width: 680px) {
  :root {
    --content: calc(100vw - 28px);
  }

  body {
    font-size: 16px;
    padding-block-end: 74px;
  }

  .site-header {
    min-height: 68px;
    padding: 8px 14px;
  }

  .brand strong {
    max-width: 180px;
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
  }

  .brand small {
    display: none;
  }

  .brand-mark {
    width: 38px;
    height: 38px;
  }

  .search-toggle {
    padding: 7px 11px;
  }

  .study-progress {
    inset-block-start: 67px;
  }

  .search-panel {
    inset-block-start: 76px;
    inset-inline: 10px;
    padding: 16px;
  }

  .search-results {
    grid-template-columns: 1fr;
  }

  .primary-nav {
    justify-content: stretch;
  }

  .primary-nav a {
    flex: 1;
    padding-inline: 8px;
    text-align: center;
  }

  .home-hero {
    gap: 40px;
    min-height: auto;
    padding-block: 55px 72px;
  }

  .hero-copy h1,
  .lesson-hero h1,
  .algorithm-hero h1,
  .simple-hero h1 {
    font-size: clamp(38px, 12vw, 58px);
  }

  .hero-lead {
    font-size: 24px;
  }

  .hero-actions {
    display: grid;
  }

  .hero-board {
    min-height: 350px;
    padding: 27px;
    border-radius: 28px 28px 28px 7px;
  }

  .board-question {
    font-size: 31px;
  }

  .board-flow {
    margin-block: 44px 28px;
  }

  .orientation-section,
  .tracks-section,
  .lesson-section,
  .algorithm-setup,
  .algorithm-terms,
  .interactive-board,
  .result-section,
  .algorithm-practice {
    padding-block: 70px;
  }

  .track-card,
  .track-card:nth-child(3),
  .track-card:nth-child(4),
  .track-card:nth-child(5),
  .track-card:nth-child(6) {
    grid-column: span 12;
    min-height: 290px;
  }

  .track-footer {
    align-items: start;
    flex-direction: column;
  }

  .track-footer span {
    max-width: 100%;
  }

  .home-exam {
    grid-template-columns: 1fr;
    gap: 26px;
    margin-block: 50px 90px;
    padding: 30px;
  }

  .breadcrumbs {
    padding-block-start: 22px;
  }

  .lesson-hero,
  .algorithm-hero {
    gap: 25px;
    padding-block: 52px 46px;
  }

  .section-nav {
    inset-block-start: 76px;
    justify-content: start;
    width: calc(100vw - 20px);
  }

  .concept-list article {
    grid-template-columns: 36px 1fr;
    gap: 14px;
  }

  .concept-list article > span {
    font-size: 22px;
  }

  .concept-list h3 {
    font-size: 23px;
  }

  .board-links,
  .exam-grid {
    grid-template-columns: 1fr;
  }

  .board-link {
    align-items: start;
    flex-direction: column;
  }

  .lesson-ending {
    grid-template-columns: 1fr;
  }

  .next-lesson {
    justify-self: stretch;
  }

  .board-header {
    align-items: start;
    flex-direction: column;
  }

  .state-grid {
    grid-template-columns: 1fr;
  }

  .frame-heading {
    align-items: start;
    flex-direction: column-reverse;
    gap: 8px;
  }

  .board-controls {
    grid-template-columns: 1fr 1fr;
  }

  .step-dots {
    grid-column: 1 / -1;
    grid-row: 1;
  }

  .board-controls .primary-control {
    grid-column: 2;
  }

  .automaton {
    min-width: 0;
  }

  .source-list article {
    align-items: start;
    grid-template-columns: 1fr;
    gap: 7px;
  }

  .print-toolbar {
    align-items: stretch;
    flex-direction: column;
  }

  .print-document {
    padding: 22px;
  }

  .print-cover h1 {
    font-size: 44px;
  }

  .site-footer {
    align-items: start;
    flex-direction: column;
    padding-block-end: 40px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
  }
}

@media print {
  @page {
    size: A4;
    margin: 16mm 14mm 18mm;
  }

  body {
    padding: 0;
    background: white;
    color: black;
    font-size: 11pt;
  }

  .site-header,
  .study-progress,
  .site-footer,
  .print-toolbar,
  .search-panel,
  .primary-nav,
  .skip-link {
    display: none !important;
  }

  #main,
  .print-document {
    width: 100%;
    margin: 0;
    padding: 0;
    box-shadow: none;
  }

  body:not([data-route="print"]) #main {
    display: block;
  }

  .print-cover {
    min-height: 230mm;
    padding-block-start: 70mm;
    break-after: page;
  }

  .print-cover h1 {
    font-size: 35pt;
  }

  .print-track {
    break-before: page;
    border: 0;
  }

  .print-track > h2 {
    font-size: 25pt;
  }

  .print-algorithm {
    break-before: page;
  }

  .print-algorithm > h3 {
    font-size: 20pt;
  }

  .board-frame {
    margin-block: 8mm;
    padding: 7mm;
    break-inside: avoid;
    border: 1px solid #555;
    background: white;
    color: black;
    box-shadow: none;
  }

  .board-frame p,
  .operation {
    color: #222;
  }

  .state-grid > div,
  .step-check {
    border: 1px solid #bbb;
    background: #f6f6f6;
  }

  .state-grid dt,
  .step-check strong {
    color: #333;
  }

  .term-band {
    break-inside: avoid;
  }

  .term {
    background: white;
  }

  .automaton line,
  .automaton circle {
    stroke: #333;
  }

  .automaton text {
    fill: #000;
  }

  .automaton marker path {
    fill: #333;
  }

  .state-table th,
  .state-table td {
    border-color: #777;
    color: black;
  }

  a {
    text-decoration: none;
  }

  details {
    display: block;
  }

  details > * {
    display: block;
  }
}