:root {
  --md-primary-fg-color: #173346;
  --md-primary-fg-color--light: #31556c;
  --md-primary-fg-color--dark: #0d2535;
  --md-primary-bg-color: #f7faf9;
  --md-primary-bg-color--light: rgba(247, 250, 249, 0.78);
  --md-accent-fg-color: #cf5136;
  --peano-paper: #f6f1e7;
  --peano-paper-deep: #ece3d3;
  --peano-ink: #152430;
  --peano-muted: #60707a;
  --peano-line: rgba(21, 36, 48, 0.16);
  --peano-accent: #cf5136;
  --peano-accent-soft: #f1d4c8;
  --peano-code: #102733;
  --peano-code-ink: #e8f0ed;
  --peano-header-ink: #f7faf9;
  --peano-header-muted: #c8d6d8;
  --peano-success: #2a7258;
}

html[dir="rtl"] .md-typeset,
html[dir="rtl"] .md-nav {
  text-align: right;
}

html[dir="rtl"] code,
html[dir="rtl"] pre,
html[dir="rtl"] textarea,
html[dir="rtl"] .peano-equation {
  direction: ltr;
  text-align: left;
}

[data-md-color-scheme="default"] {
  --md-default-bg-color: var(--peano-paper);
  --md-default-fg-color: var(--peano-ink);
  --md-default-fg-color--light: var(--peano-muted);
  --md-code-bg-color: #eae2d5;
  --md-code-fg-color: var(--peano-ink);
  --md-code-hl-number-color: #7a2f25;
  --md-code-hl-special-color: #7a294f;
  --md-code-hl-function-color: #5d3474;
  --md-code-hl-constant-color: #493d86;
  --md-code-hl-keyword-color: #174d72;
  --md-code-hl-string-color: #1f6144;
  --md-code-hl-name-color: #1d303b;
  --md-code-hl-operator-color: #394b55;
  --md-code-hl-punctuation-color: #394b55;
  --md-code-hl-comment-color: #43545d;
  --md-code-hl-generic-color: #394b55;
  --md-code-hl-variable-color: #493d67;
}

[data-md-color-scheme="slate"] {
  --md-hue: 202;
  --md-primary-fg-color: #132c3b;
  --md-primary-fg-color--light: #29495b;
  --md-primary-fg-color--dark: #0a202d;
  --md-accent-fg-color: #ef795d;
  --peano-paper: #10222c;
  --peano-paper-deep: #182e3a;
  --peano-ink: #edf1ed;
  --peano-muted: #a9b7ba;
  --peano-line: rgba(237, 241, 237, 0.15);
  --peano-accent: #ef795d;
  --peano-accent-soft: #572f2b;
  --peano-code: #081a23;
  --peano-code-ink: #edf4f0;
  --peano-success: #64c39a;
  --md-code-fg-color: #edf4f0;
  --md-code-hl-number-color: #ffb4a6;
  --md-code-hl-special-color: #ff9fbd;
  --md-code-hl-function-color: #d9b0f1;
  --md-code-hl-constant-color: #c3bdff;
  --md-code-hl-keyword-color: #a7d1ff;
  --md-code-hl-string-color: #94dcb8;
  --md-code-hl-name-color: #edf4f0;
  --md-code-hl-operator-color: #cbd9d5;
  --md-code-hl-punctuation-color: #cbd9d5;
  --md-code-hl-comment-color: #a9b9b5;
  --md-code-hl-generic-color: #cbd9d5;
  --md-code-hl-variable-color: #d6c8ef;
}

html {
  scroll-behavior: smooth;
}

body {
  background:
    linear-gradient(90deg, transparent 0, transparent calc(100% - 1px), var(--peano-line) 100%),
    var(--peano-paper);
  background-size: 72px 100%;
}

.md-header {
  background: var(--md-primary-fg-color);
  color: var(--peano-header-ink);
  backdrop-filter: blur(14px);
}

.md-header .md-header__button,
.md-header .md-header__title,
.md-header .md-header__topic,
.md-header .md-search,
.md-header .md-search__button,
.md-header .md-source {
  color: var(--peano-header-ink);
}

.md-header .md-search__button {
  border: 1px solid rgba(247, 250, 249, 0.14);
  background: rgba(247, 250, 249, 0.1);
}

.md-header .md-search__button::after {
  box-sizing: border-box;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 1rem;
  padding-block: 0;
  top: 50%;
  transform: translateY(-50%);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 0.6rem;
  font-weight: 500;
  line-height: 1;
  letter-spacing: 0;
}

.md-header .md-search__button:hover,
.md-header .md-search__button:focus-visible {
  border-color: rgba(247, 250, 249, 0.36);
  background: rgba(247, 250, 249, 0.16);
}

.md-header .md-source__fact {
  color: var(--peano-header-muted);
}

.md-tabs {
  background: var(--md-primary-fg-color--dark);
}

.md-copyright {
  color: var(--peano-ink);
}

.md-copyright a {
  color: inherit;
  text-decoration: underline;
  text-underline-offset: 0.18em;
}

.md-main__inner {
  margin-top: 1.8rem;
}

.md-content__inner {
  padding-bottom: 5rem;
}

.md-content__inner > h1 {
  margin-bottom: 1.2rem;
  color: var(--peano-ink);
  font-size: clamp(1.65rem, 2.2vw, 2.05rem);
  font-weight: 650;
  letter-spacing: -0.035em;
  line-height: 1.12;
}

.md-nav__link--active,
.md-nav__link--active > .md-ellipsis {
  color: var(--peano-ink) !important;
  font-weight: 700;
}

.md-content h2 {
  margin-top: 3.4rem;
  padding-top: 1rem;
  border-top: 1px solid var(--peano-line);
  color: var(--peano-ink);
  font-weight: 650;
  letter-spacing: -0.025em;
}

.md-content h3 {
  color: var(--peano-ink);
}

.md-typeset {
  color: var(--peano-ink);
  font-size: 0.84rem;
  line-height: 1.85;
}

.md-typeset a {
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.18em;
}

.md-typeset code {
  border-radius: 0.18rem;
}

.course-hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(18rem, 0.75fr);
  gap: clamp(2.5rem, 7vw, 6rem);
  box-sizing: border-box;
  min-height: 31rem;
  align-items: center;
  margin: -1.8rem -1.2rem 3.6rem;
  padding: clamp(2.2rem, 5vw, 4rem);
  overflow: hidden;
  background:
    linear-gradient(
      90deg,
      transparent 0,
      transparent calc(62% - 1px),
      rgba(255, 255, 255, 0.08) 62%,
      transparent calc(62% + 1px)
    ),
    var(--peano-code);
  color: var(--peano-code-ink);
  isolation: isolate;
}

.course-hero::before {
  position: absolute;
  z-index: -1;
  inset: 0;
  background:
    linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 4.5rem 4.5rem;
  mask-image: linear-gradient(90deg, transparent, black 70%);
  content: "";
}

.course-hero__content {
  max-width: 36rem;
  animation: peano-rise 700ms cubic-bezier(0.16, 1, 0.3, 1) both;
}

.course-kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 1.25rem;
  color: #f39a80;
  font-family: var(--md-code-font-family);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.course-kicker::before {
  width: 2.6rem;
  height: 1px;
  background: currentColor;
  content: "";
}

.course-hero h1 {
  max-width: 32rem;
  margin: 0;
  color: white;
  font-size: clamp(1.7rem, 2.3vw, 2.05rem);
  font-weight: 650;
  letter-spacing: -0.04em;
  line-height: 1.1;
}

.course-hero p {
  max-width: 34rem;
  margin: 1.3rem 0 0;
  color: rgba(238, 244, 240, 0.78);
  font-size: 0.95rem;
  line-height: 1.8;
}

.course-hero__diagram {
  width: 100%;
  max-width: 24rem;
  margin: 0;
  justify-self: end;
  font-family: var(--md-code-font-family);
}

.course-hero__diagram figcaption {
  margin-bottom: 1rem;
  color: #f39a80;
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.course-hero__diagram ol {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
}

.course-hero__diagram ol::before {
  position: absolute;
  top: 1.4rem;
  bottom: 1.4rem;
  left: 0.31rem;
  width: 1px;
  background: rgba(255, 255, 255, 0.18);
  content: "";
}

.course-hero__diagram li {
  position: relative;
  display: grid;
  grid-template-columns: minmax(7rem, 0.8fr) minmax(0, 1fr);
  gap: 1.2rem;
  align-items: baseline;
  padding: 0.95rem 0 0.95rem 1.6rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  opacity: 0;
  animation: peano-step-in 420ms cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.course-hero__diagram li::before {
  position: absolute;
  top: 1.48rem;
  left: 0;
  width: 0.62rem;
  height: 0.62rem;
  border: 1px solid #f39a80;
  border-radius: 50%;
  background: var(--peano-code);
  content: "";
}

.course-hero__diagram li:nth-child(2) {
  animation-delay: 90ms;
}

.course-hero__diagram li:nth-child(3) {
  animation-delay: 180ms;
}

.course-hero__diagram li:nth-child(4) {
  animation-delay: 270ms;
}

.course-hero__diagram code,
.course-hero__diagram strong {
  padding: 0;
  background: transparent;
  color: white;
  font-size: 0.86rem;
  font-weight: 600;
}

.course-hero__diagram span {
  color: rgba(238, 244, 240, 0.62);
  font-family: var(--md-text-font-family);
  font-size: 0.7rem;
}

.course-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.6rem;
}

.course-action {
  display: inline-flex;
  min-height: 2.8rem;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1rem;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 0.22rem;
  color: white !important;
  font-weight: 650;
  text-decoration: none !important;
  transition:
    border-color 180ms ease,
    background 180ms ease,
    transform 180ms ease;
}

.course-action--primary {
  border-color: var(--peano-accent);
  background: var(--peano-accent);
}

.course-action:hover {
  border-color: white;
  transform: translateY(-2px);
}

.course-action--primary:hover {
  background: #e16245;
}

.course-intro {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: clamp(2rem, 5vw, 4rem);
  align-items: start;
  margin: 3.5rem 0 4.5rem;
}

.course-intro__lead {
  margin: 0;
  color: var(--peano-ink);
  font-size: clamp(1.08rem, 1.8vw, 1.35rem);
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.6;
}

.course-intro__body {
  color: var(--peano-muted);
}

.learning-path {
  margin: 2.4rem 0 4.5rem;
  counter-reset: lesson;
}

.learning-path a {
  display: grid;
  grid-template-columns: 4rem minmax(0, 1fr) auto;
  gap: 1.2rem;
  align-items: center;
  padding: 1.4rem 0;
  border-top: 1px solid var(--peano-line);
  color: var(--peano-ink);
  text-decoration: none;
  transition: padding 180ms ease;
}

.learning-path a:last-child {
  border-bottom: 1px solid var(--peano-line);
}

.learning-path a::before {
  content: attr(data-step);
  color: var(--peano-accent);
  font-family: var(--md-code-font-family);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
}

.learning-path a::after {
  content: "→";
  color: var(--peano-muted);
  font-size: 1.3rem;
  transition: transform 180ms ease;
}

.learning-path a:hover {
  padding-right: 0.45rem;
  padding-left: 0.45rem;
}

.learning-path a:hover::after {
  transform: translateX(0.25rem);
}

.learning-path strong {
  display: block;
  margin-bottom: 0.2rem;
  font-size: 1.08rem;
}

.learning-path span {
  color: var(--peano-muted);
  font-size: 0.78rem;
}

.lesson-number {
  display: block;
  margin-bottom: 0.9rem;
  color: var(--peano-accent);
  font-family: var(--md-code-font-family);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

.lesson-layer {
  display: block;
  margin: 4rem 0 -1.15rem;
  color: var(--peano-accent);
  font-family: var(--md-code-font-family);
  font-size: 0.66rem;
  font-weight: 650;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.lesson-layer + h2 {
  margin-top: 1.15rem;
}

.lesson-lead {
  max-width: 760px;
  margin-bottom: 3.5rem;
  color: var(--peano-muted);
  font-size: clamp(0.95rem, 1.4vw, 1.08rem);
  line-height: 1.8;
}

.lesson-context {
  display: grid;
  grid-template-columns: 1fr 1fr;
  margin: 0 0 1.6rem;
  border-top: 1px solid var(--peano-line);
  border-bottom: 1px solid var(--peano-line);
}

.lesson-context > div {
  min-height: 6.2rem;
  padding: 1rem 1.2rem;
}

.lesson-context > div:first-child {
  border-right: 1px solid var(--peano-line);
}

.lesson-context strong {
  display: block;
  margin-bottom: 0.35rem;
  color: var(--peano-accent);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.lesson-context p {
  margin: 0;
  color: var(--peano-muted);
  font-size: 0.76rem;
}

.implementation-bridge {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin: 2rem 0 3rem;
  border-top: 1px solid var(--peano-line);
  border-bottom: 1px solid var(--peano-line);
}

.implementation-bridge > div {
  min-height: 7rem;
  padding: 1rem 1.1rem;
  border-right: 1px solid var(--peano-line);
}

.implementation-bridge > div:last-child {
  border-right: 0;
}

.implementation-bridge strong {
  display: block;
  margin-bottom: 0.4rem;
  color: var(--peano-accent);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.implementation-bridge p {
  margin: 0;
  color: var(--peano-muted);
  font-size: 0.76rem;
}

.implementation-bridge code {
  white-space: normal;
}

.lesson-goals {
  margin: 0 0 3.4rem;
  padding: 1.2rem 1.4rem;
  border-top: 1px solid var(--peano-line);
  border-bottom: 1px solid var(--peano-line);
  background: color-mix(in srgb, var(--peano-paper-deep) 62%, transparent);
}

.lesson-goals > strong {
  display: block;
  margin-bottom: 0.5rem;
  color: var(--peano-accent);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.lesson-goals ul {
  margin: 0.4rem 0 0.7rem;
}

.lesson-goals p {
  margin: 0;
  color: var(--peano-muted);
  font-size: 0.75rem;
}

.learning-cycle {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin: 2rem 0 4rem;
  border-top: 1px solid var(--peano-line);
  border-bottom: 1px solid var(--peano-line);
}

.learning-cycle span {
  min-height: 6rem;
  padding: 1rem;
  border-right: 1px solid var(--peano-line);
  color: var(--peano-muted);
  font-size: 0.72rem;
}

.learning-cycle span:last-child {
  border-right: 0;
}

.learning-cycle span:nth-child(3n) {
  border-right: 0;
}

.learning-cycle span:nth-child(-n + 3) {
  border-bottom: 1px solid var(--peano-line);
}

.learning-cycle strong {
  display: block;
  margin-bottom: 0.45rem;
  color: var(--peano-ink);
  font-size: 0.78rem;
}

.peano-equation {
  margin: 2.3rem 0;
  padding: clamp(1.4rem, 4vw, 2.4rem) 0;
  border-top: 1px solid var(--peano-line);
  border-bottom: 1px solid var(--peano-line);
  color: var(--peano-ink);
  font-family: var(--md-code-font-family);
  font-size: clamp(0.95rem, 2vw, 1.3rem);
  line-height: 1.6;
  text-align: center;
}

.concept-note {
  margin: 2.2rem 0;
  padding-left: 1.2rem;
  border-left: 3px solid var(--peano-accent);
}

.concept-note strong {
  display: block;
  margin-bottom: 0.25rem;
  color: var(--peano-ink);
}

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

.meta-note {
  margin: 1.7rem 0;
  padding: 0.9rem 1.1rem;
  border-top: 1px solid var(--peano-line);
  border-bottom: 1px solid var(--peano-line);
  background: color-mix(in srgb, var(--peano-paper-deep) 45%, transparent);
}

.meta-note strong {
  display: block;
  margin-bottom: 0.25rem;
  color: var(--peano-accent);
  font-size: 0.76rem;
  letter-spacing: 0.02em;
}

.meta-note p {
  margin: 0;
  color: var(--peano-muted);
}

.source-reference {
  margin: 1.6rem 0 2.2rem;
  padding: 0.8rem 0;
  border-top: 1px solid var(--peano-line);
  border-bottom: 1px solid var(--peano-line);
  color: var(--peano-muted);
  font-size: 0.76rem;
}

.source-reference strong {
  color: var(--peano-ink);
}

.source-reference p {
  margin: 0.25rem 0;
}

.source-reference a {
  font-weight: 650;
}

.learning-prompt {
  position: relative;
  margin: 2rem 0 -1.5rem;
  padding: 1rem 1.2rem 1rem 3.1rem;
  border-left: 3px solid var(--peano-accent);
  background: color-mix(in srgb, var(--peano-accent-soft) 45%, transparent);
}

.learning-prompt::before {
  position: absolute;
  top: 1rem;
  left: 1rem;
  content: "?";
  color: var(--peano-accent);
  font-family: var(--md-code-font-family);
  font-size: 1.15rem;
  font-weight: 700;
}

.learning-prompt strong {
  display: block;
  margin-bottom: 0.2rem;
}

.learning-prompt p {
  margin: 0;
}

.self-check,
.proof-note {
  margin: -1.6rem 0 3.4rem;
  padding: 0.85rem 1rem;
  border: 1px solid var(--peano-line);
  border-radius: 0.3rem;
  background: color-mix(in srgb, var(--peano-paper-deep) 52%, transparent);
}

.proof-note {
  margin: 1.5rem 0 2.2rem;
}

.self-check summary,
.proof-note summary {
  color: var(--peano-ink);
  cursor: pointer;
  font-weight: 650;
}

.self-check p,
.proof-note p {
  margin-bottom: 0;
  color: var(--peano-muted);
}

.knowledge-check {
  margin: 3rem 0;
}

.knowledge-check fieldset {
  margin: 0;
  padding: 1.2rem 1.3rem 1.3rem;
  border: 1px solid var(--peano-line);
  border-radius: 0.45rem;
}

.knowledge-check legend {
  max-width: calc(100% - 1rem);
  padding: 0 0.45rem;
  color: var(--peano-ink);
  font-weight: 650;
}

.knowledge-check label {
  display: flex;
  gap: 0.7rem;
  align-items: baseline;
  margin: 0.55rem 0;
  padding: 0.55rem 0.7rem;
  border-radius: 0.25rem;
  cursor: pointer;
}

.knowledge-check label:hover {
  background: color-mix(in srgb, var(--peano-paper-deep) 68%, transparent);
}

.knowledge-check input {
  flex: 0 0 auto;
  accent-color: var(--peano-accent);
}

.knowledge-check button {
  min-height: 2.35rem;
  margin-top: 0.7rem;
  padding: 0.5rem 0.95rem;
  border: 1px solid var(--peano-ink);
  border-radius: 999px;
  background: var(--peano-ink);
  color: var(--peano-paper);
  cursor: pointer;
  font: 650 0.72rem/1 var(--md-text-font-family);
}

.knowledge-check button:focus-visible,
.knowledge-check input:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--peano-accent) 72%, white);
  outline-offset: 3px;
}

.knowledge-check__feedback {
  min-height: 1.5rem;
  margin: 0.8rem 0 0;
  color: var(--peano-muted);
}

.knowledge-check[data-state="correct"] .knowledge-check__feedback {
  color: var(--peano-success);
  font-weight: 650;
}

.knowledge-check[data-state="incorrect"] .knowledge-check__feedback,
.knowledge-check[data-state="unanswered"] .knowledge-check__feedback {
  color: var(--peano-accent);
  font-weight: 650;
}

.peano-runner {
  margin: 2.4rem 0 3.4rem;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 0.6rem;
  background: var(--peano-code);
  box-shadow: 0 1.4rem 3.8rem rgba(11, 28, 37, 0.14);
}

.peano-runner__header {
  display: flex;
  min-height: 2.8rem;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.65rem 0.9rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(232, 240, 237, 0.72);
  font-family: var(--md-code-font-family);
  font-size: 0.64rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.peano-runner__status {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 0.42rem;
  color: rgba(232, 240, 237, 0.6);
  letter-spacing: 0;
  text-transform: none;
  white-space: nowrap;
}

.peano-runner__status::before {
  width: 0.42rem;
  height: 0.42rem;
  border-radius: 50%;
  background: #82939a;
  content: "";
}

.peano-runner[data-state="loading"] .peano-runner__status::before,
.peano-runner[data-state="running"] .peano-runner__status::before {
  background: #f1aa5b;
  animation: peano-pulse 900ms ease-in-out infinite alternate;
}

.peano-runner[data-state="success"] .peano-runner__status::before {
  background: #63c99c;
}

.peano-runner[data-state="error"] .peano-runner__status::before {
  background: #ff8067;
}

.peano-runner__editor {
  position: relative;
}

.peano-runner__source,
.peano-runner__highlight .shiki {
  display: block;
  box-sizing: border-box;
  width: 100%;
  min-height: 15rem;
  padding: 1.35rem;
  border: 0;
  background: transparent;
  font: 0.78rem/1.75 var(--md-code-font-family);
  tab-size: 4;
  white-space: pre;
}

.peano-runner__source {
  position: relative;
  z-index: 1;
  resize: vertical;
  outline: 0;
  color: var(--peano-code-ink);
  caret-color: #ff876b;
}

.peano-runner__editor[data-highlighted="true"] .peano-runner__source {
  color: transparent;
  -webkit-text-fill-color: transparent;
}

.peano-runner__highlight {
  position: absolute;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
}

.peano-runner__highlight .shiki {
  height: 100%;
  margin: 0;
  overflow: hidden;
  background: transparent !important;
}

.peano-runner__highlight code {
  display: block;
  min-width: max-content;
  background: transparent;
  font: inherit;
}

.peano-runner__source:focus {
  box-shadow: inset 3px 0 0 var(--peano-accent);
}

.peano-runner__controls {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.75rem 0.9rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.peano-runner__button {
  min-height: 2.2rem;
  padding: 0.45rem 0.85rem;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 999px;
  background: transparent;
  color: rgba(238, 244, 240, 0.82);
  cursor: pointer;
  font: 600 0.68rem/1 var(--md-text-font-family);
  transition:
    border-color 160ms ease,
    background 160ms ease,
    transform 160ms ease;
}

.peano-runner__button:hover {
  border-color: rgba(255, 255, 255, 0.55);
  transform: translateY(-1px);
}

.peano-runner__button--run {
  border-color: var(--peano-accent);
  background: var(--peano-accent);
  color: white;
}

.peano-runner__button:disabled {
  cursor: wait;
  opacity: 0.55;
  transform: none;
}

.peano-runner__shortcut {
  margin-left: auto;
  color: rgba(232, 240, 237, 0.42);
  font-family: var(--md-code-font-family);
  font-size: 0.62rem;
}

.peano-runner__output-wrap {
  padding: 1rem 1.2rem 1.25rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  background: rgba(0, 0, 0, 0.16);
}

.peano-runner__output-label {
  display: block;
  margin-bottom: 0.55rem;
  color: rgba(232, 240, 237, 0.44);
  font-family: var(--md-code-font-family);
  font-size: 0.58rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.md-typeset .peano-runner__output {
  max-height: 22rem;
  margin: 0;
  overflow: auto;
  color: #d9e7e1;
  background: transparent;
  font: 0.78rem/1.7 var(--md-code-font-family);
  white-space: pre-wrap;
}

.md-typeset .peano-runner[data-state="error"] .peano-runner__output {
  color: #ffb4a2;
}

.peano-runner[data-state="success"] .peano-runner__output,
.peano-runner[data-state="error"] .peano-runner__output {
  animation: peano-output 240ms ease-out both;
}

[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition:
    opacity 600ms ease,
    transform 600ms cubic-bezier(0.16, 1, 0.3, 1);
}

[data-reveal][data-visible="true"] {
  opacity: 1;
  transform: none;
}

@keyframes peano-rise {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
}

@keyframes peano-step-in {
  from {
    opacity: 0;
    transform: translateX(12px);
  }

  to {
    opacity: 1;
    transform: none;
  }
}

@keyframes peano-pulse {
  to {
    opacity: 0.35;
    transform: scale(0.75);
  }
}

@keyframes peano-output {
  from {
    opacity: 0;
    transform: translateY(5px);
  }
}

@media (max-width: 760px) {
  body {
    background-size: 48px 100%;
  }

  .course-hero {
    grid-template-columns: 1fr;
    gap: 2.3rem;
    min-height: auto;
    margin-right: -0.8rem;
    margin-left: -0.8rem;
    padding: 2.3rem 1.35rem 1.7rem;
    background: var(--peano-code);
  }

  .course-hero h1 {
    max-width: 22rem;
    font-size: clamp(1.55rem, 7vw, 1.8rem);
    line-height: 1.12;
  }

  .course-hero__diagram {
    max-width: none;
    justify-self: stretch;
  }

  .course-hero__diagram li {
    grid-template-columns: minmax(6.6rem, 0.75fr) minmax(0, 1fr);
    padding-top: 0.78rem;
    padding-bottom: 0.78rem;
  }

  .course-hero__diagram li::before {
    top: 1.31rem;
  }

  .course-intro {
    grid-template-columns: 1fr;
    gap: 1.2rem;
    margin: 3rem 0 4rem;
  }

  .learning-cycle {
    grid-template-columns: 1fr 1fr;
  }

  .learning-cycle span:nth-child(3n) {
    border-right: 1px solid var(--peano-line);
  }

  .learning-cycle span:nth-child(2n) {
    border-right: 0;
  }

  .learning-cycle span:nth-child(-n + 3) {
    border-bottom: 0;
  }

  .learning-cycle span:nth-child(-n + 4) {
    border-bottom: 1px solid var(--peano-line);
  }

  .learning-path a {
    grid-template-columns: 2.4rem minmax(0, 1fr) auto;
    gap: 0.7rem;
  }

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

  .lesson-context > div:first-child {
    border-right: 0;
    border-bottom: 1px solid var(--peano-line);
  }

  .implementation-bridge {
    grid-template-columns: 1fr;
  }

  .implementation-bridge > div {
    min-height: auto;
    border-right: 0;
    border-bottom: 1px solid var(--peano-line);
  }

  .implementation-bridge > div:last-child {
    border-bottom: 0;
  }

  .peano-runner {
    margin-right: -0.5rem;
    margin-left: -0.5rem;
    border-radius: 0.35rem;
  }

  .peano-runner__source,
  .peano-runner__highlight .shiki {
    min-height: 17rem;
    padding: 1rem;
    font-size: 0.76rem;
  }

  .peano-runner__shortcut {
    display: none;
  }
}

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

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

  [data-reveal] {
    opacity: 1;
    transform: none;
  }
}