:root {
  color-scheme: dark;
  --bg: #070b10;
  --bg-2: #0d141c;
  --panel: rgba(14, 21, 28, 0.82);
  --panel-strong: rgba(19, 29, 38, 0.96);
  --line: rgba(255, 255, 255, 0.12);
  --line-strong: rgba(255, 255, 255, 0.2);
  --text: #f4f8fb;
  --muted: #a8b6c7;
  --soft: #d9e4ee;
  --teal: #3de8d5;
  --teal-2: #0fb9ae;
  --gold: #f5bd4f;
  --rose: #ef6f95;
  --violet: #9d8cff;
  --green: #86efac;
  --shadow: 0 24px 90px rgba(0, 0, 0, 0.38);
  --radius: 8px;
  --radius-lg: 18px;
  --container: min(1180px, calc(100vw - 32px));
  --mono: "Cascadia Mono", "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

body.light {
  color-scheme: light;
  --bg: #f6f8fb;
  --bg-2: #e9f1f4;
  --panel: rgba(255, 255, 255, 0.82);
  --panel-strong: rgba(255, 255, 255, 0.96);
  --line: rgba(15, 23, 42, 0.12);
  --line-strong: rgba(15, 23, 42, 0.22);
  --text: #0d1720;
  --muted: #51606f;
  --soft: #1d2a36;
  --shadow: 0 22px 80px rgba(34, 57, 83, 0.16);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at 8% 12%, rgba(61, 232, 213, 0.12), transparent 28rem),
    radial-gradient(circle at 84% 8%, rgba(245, 189, 79, 0.1), transparent 30rem),
    linear-gradient(135deg, var(--bg), var(--bg-2));
  color: var(--text);
  font-family: var(--sans);
  letter-spacing: 0;
}

body.no-motion *,
body.no-motion *::before,
body.no-motion *::after {
  animation-duration: 0.001ms !important;
  animation-iteration-count: 1 !important;
  scroll-behavior: auto !important;
  transition-duration: 0.001ms !important;
}

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

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

img {
  display: block;
  max-width: 100%;
}

#chain-canvas {
  position: fixed;
  inset: 0;
  z-index: -1;
  width: 100%;
  height: 100%;
  opacity: 0.38;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 22px;
  width: 100%;
  padding: 14px max(16px, calc((100vw - 1180px) / 2));
  border-bottom: 1px solid var(--line);
  background: rgba(7, 11, 16, 0.74);
  backdrop-filter: blur(18px);
}

body.light .topbar {
  background: rgba(246, 248, 251, 0.8);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 250px;
}

.brand-mark {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border: 1px solid rgba(61, 232, 213, 0.38);
  border-radius: var(--radius);
  background: linear-gradient(135deg, rgba(61, 232, 213, 0.18), rgba(245, 189, 79, 0.16));
  color: var(--teal);
  font-family: var(--mono);
  font-size: 0.84rem;
  box-shadow: inset 0 1px 18px rgba(61, 232, 213, 0.16);
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  font-size: 0.96rem;
}

.brand small {
  color: var(--muted);
  font-size: 0.72rem;
  line-height: 1.35;
}

.main-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.04);
}

.main-nav a {
  border-radius: 999px;
  color: var(--muted);
  font-size: 0.88rem;
  padding: 8px 13px;
  transition: color 160ms ease, background 160ms ease;
}

.main-nav a:hover,
.main-nav a:focus-visible {
  background: rgba(61, 232, 213, 0.12);
  color: var(--text);
  outline: none;
}

.toolbar {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  min-width: 96px;
}

.icon-button {
  position: relative;
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  color: var(--text);
  transition: transform 170ms ease, border-color 170ms ease, background 170ms ease;
}

.icon-button:hover,
.icon-button:focus-visible {
  border-color: rgba(61, 232, 213, 0.42);
  background: rgba(61, 232, 213, 0.1);
  outline: none;
  transform: translateY(-1px);
}

.icon-button::after,
.copy-button::after {
  content: attr(data-tip);
  position: absolute;
  right: 0;
  top: calc(100% + 10px);
  min-width: max-content;
  padding: 6px 8px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--panel-strong);
  color: var(--soft);
  font-size: 0.74rem;
  opacity: 0;
  pointer-events: none;
  transform: translateY(-3px);
  transition: opacity 140ms ease, transform 140ms ease;
}

.icon-button:hover::after,
.icon-button:focus-visible::after,
.copy-button:hover::after,
.copy-button:focus-visible::after {
  opacity: 1;
  transform: translateY(0);
}

.icon-lines,
.icon-moon {
  position: relative;
  width: 18px;
  height: 18px;
}

.icon-lines::before,
.icon-lines::after {
  content: "";
  position: absolute;
  left: 2px;
  width: 14px;
  height: 2px;
  border-radius: 999px;
  background: var(--teal);
  box-shadow: 0 6px 0 var(--gold);
}

.icon-lines::before {
  top: 4px;
}

.icon-lines::after {
  top: 16px;
}

.icon-moon {
  border: 2px solid var(--gold);
  border-radius: 50%;
}

.icon-moon::after {
  content: "";
  position: absolute;
  left: 6px;
  top: -2px;
  width: 14px;
  height: 18px;
  border-radius: 50%;
  background: var(--panel-strong);
}

main {
  overflow: hidden;
}

.study-console,
.example-library,
.quiz-section,
.repo-section {
  width: var(--container);
  margin: 0 auto;
}

.study-console {
  display: grid;
  grid-template-columns: minmax(0, 0.96fr) minmax(340px, 0.78fr);
  gap: 24px;
  align-items: start;
  min-height: calc(100vh - 76px);
  padding: 34px 0 58px;
}

.console-copy {
  position: relative;
  z-index: 2;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--teal);
  font-family: var(--mono);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 760px;
  margin-bottom: 18px;
  color: var(--text);
  font-size: clamp(2.35rem, 5vw, 3.8rem);
  line-height: 0.98;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 12px;
  font-size: clamp(1.8rem, 4vw, 3.2rem);
  line-height: 1.04;
  letter-spacing: 0;
}

h3 {
  font-size: 1.08rem;
  letter-spacing: 0;
}

.lead {
  max-width: 680px;
  color: var(--muted);
  font-size: 1rem;
  line-height: 1.62;
}

.search-panel {
  max-width: 650px;
  margin-top: 22px;
}

.search-panel label {
  display: block;
  margin-bottom: 9px;
  color: var(--soft);
  font-size: 0.84rem;
  font-weight: 700;
}

.search-box {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 58px;
  padding: 0 17px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: var(--panel-strong);
  box-shadow: var(--shadow);
}

.search-box span {
  position: relative;
  display: inline-block;
  width: 18px;
  height: 18px;
  flex: 0 0 18px;
  border: 2px solid var(--teal);
  border-radius: 50%;
}

.search-box span::after {
  content: "";
  position: absolute;
  right: -7px;
  bottom: -5px;
  width: 9px;
  height: 2px;
  border-radius: 999px;
  background: var(--teal);
  transform: rotate(45deg);
}

.search-box input {
  width: 100%;
  min-width: 0;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--text);
  font-size: 1rem;
}

.metric-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  max-width: 650px;
  margin-top: 14px;
}

.metric-row div {
  min-height: 72px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.045);
}

.metric-row strong,
.metric-row span {
  display: block;
}

.metric-row strong {
  color: var(--gold);
  font-family: var(--mono);
  font-size: 1.34rem;
}

.metric-row span {
  margin-top: 5px;
  color: var(--muted);
  font-size: 0.82rem;
}

.visual-wrap {
  position: relative;
  min-height: 360px;
  align-self: stretch;
}

.visual-wrap img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.visual-wrap::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  background: linear-gradient(180deg, transparent 42%, rgba(7, 11, 16, 0.7));
  pointer-events: none;
}

.orbit {
  position: absolute;
  border: 1px solid rgba(61, 232, 213, 0.38);
  border-radius: 50%;
  pointer-events: none;
}

.orbit-one {
  right: 10%;
  top: 14%;
  width: 145px;
  height: 145px;
  animation: floaty 7s ease-in-out infinite;
}

.orbit-two {
  left: 12%;
  bottom: 12%;
  width: 88px;
  height: 88px;
  border-color: rgba(245, 189, 79, 0.4);
  animation: floaty 8s ease-in-out infinite reverse;
}

.floating-badge {
  position: absolute;
  z-index: 2;
  max-width: 210px;
  padding: 10px 12px;
  border: 1px solid rgba(61, 232, 213, 0.32);
  border-radius: var(--radius);
  background: rgba(7, 11, 16, 0.74);
  color: var(--soft);
  font-family: var(--mono);
  font-size: 0.78rem;
  box-shadow: var(--shadow);
  backdrop-filter: blur(16px);
}

.badge-a {
  left: -18px;
  top: 24%;
  animation: drift 8s ease-in-out infinite;
}

.badge-b {
  right: -12px;
  bottom: 20%;
  animation: drift 9s ease-in-out infinite reverse;
}

.notes-workbench {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: minmax(230px, 0.66fr) minmax(0, 1.1fr) minmax(300px, 0.86fr);
  gap: 14px;
  align-items: stretch;
  min-height: 500px;
  padding-top: 2px;
}

.lesson-list,
.lesson-panel,
.code-stage,
.quiz-card,
.glossary-panel,
.repo-tree,
.principles {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
}

.lesson-list,
.lesson-panel,
.code-stage {
  min-width: 0;
}

.lesson-list {
  padding: 12px;
  overflow: hidden;
}

.rail-head,
.code-head,
.quiz-topline,
.panel-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.rail-head {
  margin-bottom: 10px;
  color: var(--soft);
  font-size: 0.82rem;
  font-weight: 800;
  text-transform: uppercase;
}

.rail-head button {
  border: 1px solid var(--line);
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  font-size: 0.78rem;
  padding: 6px 10px;
}

#lessonList {
  display: grid;
  gap: 8px;
  max-height: 456px;
  overflow: auto;
  padding-right: 2px;
}

.lesson-tab {
  display: grid;
  grid-template-columns: 34px 1fr auto;
  gap: 10px;
  align-items: center;
  width: 100%;
  min-height: 68px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.045);
  color: var(--text);
  padding: 10px;
  text-align: left;
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease;
}

.lesson-tab:hover,
.lesson-tab:focus-visible,
.lesson-tab.active {
  border-color: rgba(61, 232, 213, 0.42);
  background: rgba(61, 232, 213, 0.09);
  outline: none;
  transform: translateX(2px);
}

.lesson-tab.done .lesson-index {
  color: var(--green);
  border-color: rgba(134, 239, 172, 0.46);
}

.lesson-index {
  display: grid;
  width: 32px;
  height: 32px;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--gold);
  font-family: var(--mono);
  font-size: 0.82rem;
}

.lesson-name {
  display: block;
  color: var(--soft);
  font-weight: 800;
}

.lesson-meta {
  display: block;
  margin-top: 3px;
  color: var(--muted);
  font-size: 0.76rem;
}

.lesson-status {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--line-strong);
}

.lesson-tab.done .lesson-status {
  background: var(--green);
  box-shadow: 0 0 0 5px rgba(134, 239, 172, 0.12);
}

.lesson-panel {
  padding: 24px;
  overflow: hidden;
}

.lesson-kicker {
  margin-bottom: 12px;
  color: var(--teal);
  font-family: var(--mono);
  font-size: 0.78rem;
}

.lesson-panel h2 {
  font-size: 2rem;
}

.lesson-panel p {
  color: var(--muted);
  line-height: 1.7;
}

.lesson-body {
  display: grid;
  gap: 12px;
  margin-top: 18px;
}

.note-row {
  position: relative;
  padding-left: 20px;
  color: var(--soft);
  line-height: 1.65;
}

.note-row::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.74em;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--gold);
}

.checklist {
  display: grid;
  gap: 9px;
  margin-top: 22px;
}

.check-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  color: var(--muted);
  font-size: 0.92rem;
}

.check-item span {
  display: grid;
  width: 20px;
  height: 20px;
  flex: 0 0 20px;
  place-items: center;
  border: 1px solid rgba(61, 232, 213, 0.42);
  border-radius: 6px;
  color: var(--teal);
  font-size: 0.72rem;
}

.lesson-actions,
.quiz-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.primary-action,
.secondary-action,
.copy-button {
  min-height: 42px;
  border-radius: var(--radius);
  font-weight: 800;
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease;
}

.primary-action {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  border: 0;
  background: linear-gradient(135deg, var(--teal), var(--gold));
  color: #071016;
  padding: 0 16px;
}

.primary-action span {
  font-size: 1.2rem;
  line-height: 1;
}

.secondary-action,
.copy-button {
  border: 1px solid var(--line-strong);
  background: rgba(255, 255, 255, 0.055);
  color: var(--soft);
  padding: 0 14px;
}

.primary-action:hover,
.primary-action:focus-visible,
.secondary-action:hover,
.secondary-action:focus-visible,
.copy-button:hover,
.copy-button:focus-visible {
  outline: none;
  transform: translateY(-1px);
}

.secondary-action:hover,
.secondary-action:focus-visible,
.copy-button:hover,
.copy-button:focus-visible {
  border-color: rgba(61, 232, 213, 0.42);
  background: rgba(61, 232, 213, 0.1);
}

.code-stage {
  display: grid;
  grid-template-rows: auto 1fr;
  overflow: hidden;
}

.code-head {
  min-height: 66px;
  padding: 13px 14px;
  border-bottom: 1px solid var(--line);
}

.code-head span,
.code-head strong {
  display: block;
}

.code-head span {
  color: var(--gold);
  font-family: var(--mono);
  font-size: 0.74rem;
}

.code-head strong {
  margin-top: 3px;
  color: var(--soft);
  font-size: 0.9rem;
}

.copy-button {
  position: relative;
}

pre {
  margin: 0;
  min-width: 0;
  overflow: auto;
  background:
    linear-gradient(90deg, rgba(61, 232, 213, 0.07), transparent 18rem),
    rgba(2, 6, 10, 0.42);
}

code {
  display: block;
  min-width: 520px;
  padding: 18px;
  color: #dce9f7;
  font-family: var(--mono);
  font-size: 0.82rem;
  line-height: 1.62;
  white-space: pre;
}

body.light code {
  color: #0f172a;
}

.example-library,
.quiz-section,
.repo-section {
  padding: 72px 0;
}

.section-heading {
  max-width: 760px;
}

.section-heading p:not(.eyebrow) {
  color: var(--muted);
  font-size: 1rem;
  line-height: 1.72;
}

.filter-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 26px 0 18px;
}

.filter-chip {
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.04);
  color: var(--muted);
  font-weight: 800;
  padding: 0 15px;
}

.filter-chip.active,
.filter-chip:hover,
.filter-chip:focus-visible {
  border-color: rgba(61, 232, 213, 0.42);
  background: rgba(61, 232, 213, 0.12);
  color: var(--text);
  outline: none;
}

.example-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.example-card {
  display: grid;
  gap: 13px;
  min-height: 310px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  box-shadow: var(--shadow);
  transition: transform 170ms ease, border-color 170ms ease;
}

.example-card:hover,
.example-card:focus-within {
  border-color: rgba(61, 232, 213, 0.36);
  transform: translateY(-3px);
}

.card-topline {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.pill {
  display: inline-flex;
  min-height: 26px;
  align-items: center;
  border: 1px solid rgba(245, 189, 79, 0.34);
  border-radius: 999px;
  color: var(--gold);
  font-family: var(--mono);
  font-size: 0.72rem;
  padding: 0 9px;
}

.example-card h3 {
  margin-bottom: 0;
}

.example-card p {
  color: var(--muted);
  line-height: 1.62;
}

.mini-code {
  max-height: 150px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(0, 0, 0, 0.18);
}

.mini-code code {
  min-width: 0;
  padding: 12px;
  font-size: 0.72rem;
  line-height: 1.5;
}

.card-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
  align-self: end;
}

.quiz-layout,
.repo-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.96fr) minmax(280px, 0.72fr);
  gap: 14px;
  margin-top: 26px;
}

.quiz-card,
.glossary-panel,
.repo-tree,
.principles {
  padding: 22px;
}

.quiz-topline {
  color: var(--teal);
  font-family: var(--mono);
  font-size: 0.8rem;
}

.quiz-card h3 {
  margin: 20px 0;
  font-size: 1.55rem;
  line-height: 1.22;
}

.quiz-options {
  display: grid;
  gap: 10px;
}

.quiz-option {
  display: flex;
  width: 100%;
  min-height: 54px;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.045);
  color: var(--soft);
  padding: 12px 14px;
  text-align: left;
}

.quiz-option:hover,
.quiz-option:focus-visible {
  border-color: rgba(61, 232, 213, 0.42);
  outline: none;
}

.quiz-option.correct {
  border-color: rgba(134, 239, 172, 0.7);
  background: rgba(134, 239, 172, 0.12);
}

.quiz-option.wrong {
  border-color: rgba(239, 111, 149, 0.75);
  background: rgba(239, 111, 149, 0.13);
}

.quiz-feedback {
  min-height: 48px;
  margin: 18px 0 0;
  color: var(--muted);
  line-height: 1.58;
}

.panel-head {
  margin-bottom: 16px;
}

.panel-head span {
  color: var(--soft);
  font-weight: 900;
}

.panel-head input {
  width: min(190px, 52%);
  min-height: 38px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.05);
  color: var(--text);
  padding: 0 10px;
}

dl {
  display: grid;
  gap: 12px;
  margin: 0;
}

dt {
  color: var(--teal);
  font-family: var(--mono);
  font-size: 0.8rem;
}

dd {
  margin: 5px 0 0;
  color: var(--muted);
  line-height: 1.58;
}

.repo-tree {
  display: grid;
  gap: 10px;
}

.repo-tree div {
  display: grid;
  grid-template-columns: minmax(130px, 0.4fr) 1fr;
  gap: 14px;
  align-items: center;
  min-height: 52px;
  border-bottom: 1px solid var(--line);
}

.repo-tree div:last-child {
  border-bottom: 0;
}

.repo-tree span {
  color: var(--gold);
  font-family: var(--mono);
  font-size: 0.88rem;
}

.repo-tree small {
  color: var(--muted);
  line-height: 1.5;
}

.principles h3 {
  margin-bottom: 14px;
}

.principles ul {
  display: grid;
  gap: 12px;
  margin: 0;
  padding-left: 20px;
  color: var(--muted);
  line-height: 1.6;
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: var(--container);
  margin: 0 auto;
  padding: 30px 0 46px;
  border-top: 1px solid var(--line);
  color: var(--muted);
}

.site-footer a {
  color: var(--teal);
  font-weight: 800;
}

.toast {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 40;
  max-width: min(360px, calc(100vw - 36px));
  padding: 12px 14px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: var(--panel-strong);
  color: var(--soft);
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transform: translateY(12px);
  transition: opacity 160ms ease, transform 160ms ease;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 600ms ease, transform 600ms ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@keyframes floaty {
  0%,
  100% {
    transform: translate3d(0, 0, 0) rotate(0deg);
  }
  50% {
    transform: translate3d(7px, -10px, 0) rotate(9deg);
  }
}

@keyframes drift {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

@media (max-width: 1080px) {
  .topbar {
    flex-wrap: wrap;
  }

  .brand {
    min-width: 0;
  }

  .main-nav {
    order: 3;
    width: 100%;
    overflow-x: auto;
    justify-content: flex-start;
  }

  .study-console {
    grid-template-columns: 1fr;
  }

  .visual-wrap {
    min-height: 380px;
  }

  .notes-workbench {
    grid-template-columns: 1fr 1fr;
  }

  .lesson-list {
    grid-column: 1 / -1;
  }

  #lessonList {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    max-height: none;
  }

  .example-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 760px) {
  :root {
    --container: min(100vw - 22px, 1180px);
  }

  .topbar {
    padding: 12px;
  }

  .brand small {
    display: none;
  }

  .toolbar {
    min-width: 88px;
  }

  h1 {
    font-size: 2.55rem;
  }

  .study-console {
    min-height: auto;
    padding-top: 34px;
  }

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

  .visual-wrap {
    min-height: 310px;
  }

  .floating-badge {
    display: none;
  }

  .notes-workbench,
  .example-grid,
  .quiz-layout,
  .repo-grid {
    grid-template-columns: 1fr;
  }

  #lessonList {
    grid-template-columns: 1fr;
  }

  .lesson-panel,
  .quiz-card,
  .glossary-panel,
  .repo-tree,
  .principles {
    padding: 18px;
  }

  .repo-tree div {
    grid-template-columns: 1fr;
    gap: 4px;
    padding-bottom: 10px;
  }

  .site-footer {
    align-items: flex-start;
    flex-direction: column;
    gap: 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.001ms !important;
  }
}