:root {
  color-scheme: light;
  --ink: #17201d;
  --muted: #65716d;
  --paper: #fbfaf6;
  --soft: #f0ece1;
  --line: #d9d4c7;
  --green: #2e6f5e;
  --blue: #245e8f;
  --red: #a85142;
  --gold: #b57d21;
  --white: #ffffff;
  --shadow: 0 18px 55px rgba(34, 39, 35, 0.13);
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
}

a {
  color: inherit;
}

code,
pre {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

:not(pre) > code {
  overflow-wrap: anywhere;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -4rem;
  z-index: 30;
  background: var(--ink);
  color: var(--white);
  padding: 0.6rem 0.8rem;
  border-radius: var(--radius);
}

.skip-link:focus {
  top: 1rem;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
  padding: 0.75rem clamp(1rem, 4vw, 4rem);
  background: rgba(251, 250, 246, 0.9);
  border-bottom: 1px solid rgba(217, 212, 199, 0.8);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: var(--radius);
  background: var(--ink);
  color: var(--white);
  font-weight: 800;
}

.brand small {
  display: block;
  color: var(--muted);
  font-size: 0.75rem;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

.site-nav a {
  min-height: 40px;
  padding: 0.55rem 0.8rem;
  border-radius: var(--radius);
  color: #36423e;
  font-weight: 650;
  text-decoration: none;
}

.site-nav a[aria-current="page"],
.site-nav a:hover,
.site-nav a:focus-visible {
  background: var(--soft);
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 4px auto;
  background: var(--ink);
}

.section-band {
  background:
    linear-gradient(90deg, rgba(46, 111, 94, 0.08), rgba(36, 94, 143, 0.08)),
    var(--soft);
}

.home-hero {
  position: relative;
  display: grid;
  min-height: calc(82vh - 72px);
  padding: clamp(2rem, 7vw, 6rem) clamp(1rem, 6vw, 5rem);
  overflow: hidden;
}

.home-copy {
  position: relative;
  z-index: 1;
  max-width: 820px;
  align-self: end;
}

.home-copy h1 {
  margin: 0;
  max-width: 860px;
  font-size: clamp(2.8rem, 8vw, 6.8rem);
  line-height: 0.98;
  letter-spacing: 0;
}

.home-visual {
  position: absolute;
  inset: auto clamp(1rem, 6vw, 5rem) clamp(1rem, 4vw, 3rem) auto;
  width: min(46vw, 620px);
  min-width: 360px;
  height: min(42vh, 420px);
  overflow: hidden;
  border: 1px solid rgba(23, 32, 29, 0.14);
  border-radius: var(--radius);
  background: #f8f4ea;
  box-shadow: var(--shadow);
  opacity: 0.92;
}

.home-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  border: 1px solid rgba(255, 255, 255, 0.35);
  pointer-events: none;
}

.home-visual #modelCanvas {
  min-height: 100%;
}

.home-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 1.5rem;
  max-width: 720px;
}

.home-stats span {
  min-height: 58px;
  padding: 0.75rem 0.9rem;
  border: 1px solid rgba(23, 32, 29, 0.14);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.68);
  color: var(--muted);
  font-weight: 750;
}

.home-stats b {
  display: block;
  color: var(--ink);
  font-size: 1.15rem;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(360px, 1.1fr);
  gap: clamp(2rem, 5vw, 5rem);
  align-items: center;
  min-height: calc(100vh - 72px);
  padding: clamp(2rem, 7vw, 6rem) clamp(1rem, 6vw, 5rem);
}

.hero h1,
.section-heading h1,
.section-heading h2 {
  margin: 0;
  max-width: 860px;
  font-size: clamp(2.15rem, 5vw, 4.9rem);
  line-height: 1.02;
  letter-spacing: 0;
}

.section-heading h1,
.section-heading h2 {
  font-size: clamp(1.9rem, 3.2vw, 3.2rem);
}

.catalog-title {
  max-width: 820px;
}

.eyebrow {
  margin: 0 0 0.7rem;
  color: var(--green);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.lead {
  max-width: 640px;
  color: #43504b;
  font-size: clamp(1.05rem, 2vw, 1.28rem);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 2rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0.72rem 1rem;
  border: 1px solid var(--ink);
  border-radius: var(--radius);
  font-weight: 800;
  text-decoration: none;
}

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

.button.secondary {
  background: transparent;
}

.continue-card {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  align-items: center;
  margin-top: 1rem;
  padding: 0.75rem 0.9rem;
  border: 1px solid rgba(46, 111, 94, 0.22);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.74);
}

.continue-card[hidden] {
  display: none;
}

.continue-card strong {
  color: var(--ink);
}

.hero-visual {
  position: relative;
  min-height: 460px;
  overflow: hidden;
  border: 1px solid rgba(23, 32, 29, 0.16);
  border-radius: var(--radius);
  background: #f8f4ea;
  box-shadow: var(--shadow);
}

#modelCanvas {
  display: block;
  width: 100%;
  height: 100%;
  min-height: 460px;
}

.home-visual #modelCanvas {
  min-height: 0;
}

.metric-strip {
  position: absolute;
  right: 1rem;
  bottom: 1rem;
  left: 1rem;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.6rem;
}

.metric-strip span {
  min-width: 0;
  padding: 0.75rem;
  border: 1px solid rgba(23, 32, 29, 0.15);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.84);
  color: var(--muted);
  font-size: 0.82rem;
}

.metric-strip b {
  display: block;
  color: var(--ink);
  font-size: 1.2rem;
}

.content-section {
  padding: clamp(3rem, 7vw, 6rem) clamp(1rem, 6vw, 5rem);
}

.compact-heading {
  max-width: 760px;
  margin-bottom: 1.5rem;
}

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

.promo-grid article {
  min-width: 0;
  min-height: 220px;
  padding: clamp(1rem, 2.4vw, 1.35rem);
  border: 1px solid rgba(23, 32, 29, 0.13);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.82);
}

.promo-grid h3 {
  margin: 0 0 0.6rem;
  font-size: clamp(1.2rem, 2vw, 1.55rem);
  line-height: 1.18;
}

.promo-grid p {
  margin: 0;
  color: var(--muted);
}

.landing-cta {
  display: grid;
  grid-template-columns: minmax(0, 0.68fr) minmax(260px, 0.32fr);
  gap: clamp(1.25rem, 5vw, 4rem);
  align-items: center;
}

.landing-cta h2 {
  margin: 0;
  max-width: 780px;
  font-size: clamp(1.9rem, 3.2vw, 3.4rem);
  line-height: 1.05;
  letter-spacing: 0;
}

.landing-cta p:not(.eyebrow) {
  max-width: 720px;
  color: #43504b;
  font-size: 1.08rem;
}

.landing-cta .hero-actions {
  justify-content: flex-end;
  margin-top: 0;
}

.course-page {
  background: var(--paper);
}

.course-shell {
  display: grid;
  grid-template-columns: minmax(220px, 0.25fr) minmax(0, 0.75fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  padding: clamp(2rem, 6vw, 5rem) clamp(1rem, 6vw, 5rem);
}

.course-sidebar {
  position: sticky;
  top: 96px;
  align-self: start;
  display: grid;
  gap: 0.45rem;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.course-sidebar a,
.text-link {
  color: var(--green);
  font-weight: 800;
  text-decoration: none;
}

.course-sidebar a {
  padding: 0.45rem 0.5rem;
  border-radius: var(--radius);
}

.course-sidebar a[aria-current="page"],
.course-sidebar a:hover,
.course-sidebar a:focus-visible {
  background: #e7efe9;
}

.course-content {
  min-width: 0;
  max-width: 980px;
}

.course-hero {
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--line);
}

.course-hero h1 {
  margin: 0;
  font-size: clamp(2.1rem, 5vw, 4rem);
  line-height: 1.06;
  letter-spacing: 0;
}

.course-hero p {
  max-width: 780px;
  color: var(--muted);
  font-size: 1.08rem;
}

.course-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  margin: 1.1rem 0 0;
  padding: 0;
  list-style: none;
}

.course-meta li {
  font-size: 0.92rem;
  color: var(--muted);
}

.course-meta strong {
  margin-right: 0.4rem;
  color: #1f2b25;
  font-weight: 800;
}

.course-outcomes {
  margin: 1rem 0 0;
  padding: 1rem;
  border: 1px solid rgba(46, 111, 94, 0.18);
  border-radius: var(--radius);
  background: #eef5ef;
}

.course-outcomes strong {
  display: block;
  margin-bottom: 0.45rem;
  color: var(--green);
  font-weight: 900;
}

.course-outcomes ul {
  display: grid;
  gap: 0.35rem;
  margin: 0;
  padding-left: 1.1rem;
}

.course-outcomes li {
  color: #34413c;
}

.module-nav {
  position: sticky;
  top: 72px;
  z-index: 12;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--line);
  background: rgba(251, 250, 246, 0.94);
  backdrop-filter: blur(14px);
}

.module-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 38px;
  padding: 0.45rem 0.7rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  color: #34413c;
  font-size: 0.9rem;
  font-weight: 800;
  text-decoration: none;
}

.module-nav a:hover,
.module-nav a:focus-visible {
  border-color: var(--green);
  background: #e7efe9;
}

.lesson-block {
  padding: 2rem 0;
  border-bottom: 1px solid var(--line);
}

.lesson-block h2 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.45rem, 3vw, 2.2rem);
  letter-spacing: 0;
}

.lesson-block h3 {
  margin: 1.4rem 0 0.4rem;
}

.lesson-block p,
.lesson-block li {
  color: #3f4b46;
}

.lesson-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.lesson-card {
  min-width: 0;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.lesson-card h3 {
  margin-top: 0;
}

.callout {
  margin: 1rem 0 0;
  padding: 1rem;
  border-left: 4px solid var(--gold);
  border-radius: var(--radius);
  background: #fff7e4;
}

.callout strong {
  display: block;
  margin-bottom: 0.25rem;
  color: #6f4b12;
}

.callout p {
  margin: 0;
}

.quiz-item {
  margin: 1rem 0 0;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.quiz-item p {
  margin: 0 0 0.75rem;
}

.quiz-answer {
  display: none;
  margin-top: 0.75rem;
  padding: 0.85rem 1rem;
  border-left: 4px solid var(--green);
  border-radius: var(--radius);
  background: #e7efe9;
}

.quiz-answer.is-open {
  display: block;
}

.quiz-answer p {
  margin: 0;
}

.formula {
  margin: 1rem 0 0;
  padding: 0.9rem 1.1rem;
  border: 1px solid var(--line);
  border-left: 4px solid var(--blue);
  border-radius: var(--radius);
  background: #f4f8fb;
  color: var(--ink);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 1.02rem;
  text-align: center;
  overflow-x: auto;
}

.formula .formula-label {
  display: block;
  margin-top: 0.4rem;
  color: var(--muted);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 0.8rem;
}

.formula sub,
.formula sup {
  font-size: 0.72em;
}

.compact-table {
  width: 100%;
  margin: 1rem 0 0;
  border: 1px solid var(--line);
  border-collapse: separate;
  border-spacing: 0;
  border-radius: var(--radius);
  background: var(--white);
  overflow: hidden;
}

.compact-table th,
.compact-table td {
  padding: 0.75rem;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.compact-table th {
  background: #e7efe9;
  color: var(--green);
  font-size: 0.9rem;
  font-weight: 900;
}

.compact-table td {
  color: #3f4b46;
}

.compact-table th:last-child,
.compact-table td:last-child {
  border-right: 0;
}

.compact-table tr:last-child td {
  border-bottom: 0;
}

.step-list {
  display: grid;
  gap: 0.75rem;
  margin: 1rem 0 0;
}

.step-list article {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 0.85rem;
  align-items: start;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.step-list span {
  display: grid;
  min-width: 44px;
  height: 44px;
  place-items: center;
  border-radius: var(--radius);
  background: var(--ink);
  color: var(--white);
  font-size: 0.85rem;
  font-weight: 900;
}

.step-list strong {
  display: block;
  margin-bottom: 0.2rem;
}

.step-list p {
  margin: 0;
}

.visual-panel {
  display: grid;
  grid-template-columns: minmax(0, 0.56fr) minmax(260px, 0.44fr);
  gap: 1rem;
  align-items: stretch;
  margin-top: 1rem;
}

.diagram,
.practice-panel {
  min-width: 0;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.diagram h3,
.practice-panel h3 {
  margin-top: 0;
}

.flow-diagram {
  display: grid;
  gap: 0.65rem;
}

.flow-step {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 0.7rem;
  align-items: center;
  padding: 0.75rem;
  border: 1px solid rgba(23, 32, 29, 0.12);
  border-radius: var(--radius);
  background: #fbfaf6;
}

.flow-step span {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: 50%;
  background: var(--green);
  color: var(--white);
  font-weight: 900;
}

.flow-step:nth-child(2) span,
.flow-step:nth-child(5) span {
  background: var(--blue);
}

.flow-step:nth-child(3) span,
.flow-step:nth-child(6) span {
  background: var(--red);
}

.matrix-diagram {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.4rem;
  margin-top: 1rem;
}

.matrix-diagram span {
  min-height: 42px;
  display: grid;
  place-items: center;
  border-radius: var(--radius);
  background: #e7efe9;
  color: var(--green);
  font-weight: 900;
}

.matrix-diagram span:nth-child(3n) {
  background: #e9eff5;
  color: var(--blue);
}

.split-diagram {
  display: grid;
  grid-template-columns: 1.8fr 0.7fr 0.5fr;
  gap: 0.4rem;
  margin-top: 1rem;
}

.split-diagram span {
  min-height: 64px;
  display: grid;
  place-items: center;
  border-radius: var(--radius);
  color: var(--white);
  font-weight: 900;
}

.split-diagram span:nth-child(1) {
  background: var(--green);
}

.split-diagram span:nth-child(2) {
  background: var(--blue);
}

.split-diagram span:nth-child(3) {
  background: var(--red);
}

.tree-diagram {
  display: grid;
  gap: 0.5rem;
  justify-items: center;
  margin-top: 1rem;
}

.tree-row {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  width: 100%;
}

.tree-node {
  min-width: 86px;
  padding: 0.55rem 0.7rem;
  border-radius: var(--radius);
  background: #e7efe9;
  color: var(--green);
  text-align: center;
  font-weight: 900;
}

.tree-row:nth-child(2) .tree-node {
  background: #e9eff5;
  color: var(--blue);
}

.tree-row:nth-child(3) .tree-node {
  background: #f4e9e6;
  color: var(--red);
}

.answer-card {
  display: none;
  margin-top: 0.75rem;
  padding: 0.85rem;
  border-left: 4px solid var(--green);
  border-radius: var(--radius);
  background: #eef5ef;
}

.answer-card.is-open {
  display: block;
}

.progress-list {
  display: grid;
  gap: 0.55rem;
  margin: 1rem 0;
}

.progress-list label {
  display: flex;
  gap: 0.55rem;
  align-items: flex-start;
  padding: 0.65rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fbfaf6;
  font-weight: 700;
}

.progress-list input {
  margin-top: 0.25rem;
  accent-color: var(--green);
}

.progress-status {
  color: var(--muted);
  font-weight: 800;
}

.course-next {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  padding-top: 2rem;
}

.section-heading {
  max-width: 920px;
  margin-bottom: clamp(1.6rem, 4vw, 3rem);
}

.section-heading p:not(.eyebrow) {
  max-width: 760px;
  color: var(--muted);
  font-size: 1.05rem;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--line);
}

.timeline article,
.module-card,
.foundation-card,
.deploy-grid article {
  background: rgba(255, 255, 255, 0.78);
}

.timeline article {
  min-height: 238px;
  padding: 1.2rem;
}

.timeline span,
.step span {
  display: inline-grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: 50%;
  background: #e7efe9;
  color: var(--green);
  font-weight: 800;
}

.timeline h3,
.foundation-card h3,
.module-card h3,
.algorithm-panel h3,
.workflow-panel h3,
.deploy-grid h3 {
  margin: 1rem 0 0.45rem;
  font-size: 1.1rem;
}

.timeline p,
.foundation-card p,
.module-card p,
.algorithm-panel p,
.deploy-grid p,
.workflow-panel p {
  color: var(--muted);
}

.foundation-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr;
  gap: 1rem;
}

.foundation-card {
  min-width: 0;
  min-height: 280px;
  padding: 1.25rem;
  border: 1px solid rgba(23, 32, 29, 0.12);
  border-radius: var(--radius);
}

.foundation-card ul {
  margin: 1rem 0 0;
  padding-left: 1.1rem;
  color: #3f4b46;
}

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

.module-card {
  min-height: 330px;
  padding: 1.25rem;
  border: 1px solid rgba(23, 32, 29, 0.12);
  border-radius: var(--radius);
}

.module-icon {
  display: grid;
  width: 46px;
  height: 46px;
  place-items: center;
  border-radius: var(--radius);
  background: var(--green);
  color: var(--white);
  font-weight: 900;
}

.module-card:nth-child(2) .module-icon,
.module-card:nth-child(5) .module-icon {
  background: var(--blue);
}

.module-card:nth-child(3) .module-icon,
.module-card:nth-child(6) .module-icon {
  background: var(--red);
}

.module-card ul {
  margin: 1rem 0 0;
  padding-left: 1.1rem;
  color: #3f4b46;
}

.module-hub {
  display: grid;
  gap: 1rem;
}

.module-group {
  display: grid;
  grid-template-columns: minmax(260px, 0.34fr) minmax(0, 0.66fr);
  gap: 1rem;
  padding: clamp(1rem, 2.6vw, 1.5rem);
  border: 1px solid rgba(23, 32, 29, 0.13);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.78);
}

.module-group header {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}

.module-number {
  display: grid;
  min-width: 62px;
  min-height: 42px;
  place-items: center;
  border-radius: var(--radius);
  background: var(--ink);
  color: var(--white);
  font-size: 0.82rem;
  font-weight: 900;
}

.module-group h2,
.module-group h3 {
  margin: 0 0 0.35rem;
  font-size: clamp(1.35rem, 2.4vw, 2rem);
  line-height: 1.18;
}

.module-group p {
  margin: 0;
  color: var(--muted);
}

.group-action {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  margin-top: 1rem;
  padding: 0.52rem 0.75rem;
  border: 1px solid var(--ink);
  border-radius: var(--radius);
  background: var(--ink);
  color: var(--white);
  font-size: 0.92rem;
  font-weight: 850;
  text-decoration: none;
}

.group-action:hover,
.group-action:focus-visible {
  background: var(--green);
  border-color: var(--green);
}

.submodule-list {
  display: grid;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  overflow: hidden;
}

.submodule-list a {
  display: grid;
  grid-template-columns: minmax(150px, 0.32fr) minmax(0, 0.68fr);
  gap: 1rem;
  align-items: center;
  min-height: 72px;
  padding: 0.9rem 1rem;
  border-bottom: 1px solid var(--line);
  color: inherit;
  text-decoration: none;
}

.submodule-list a:last-child {
  border-bottom: 0;
}

.submodule-list a:hover,
.submodule-list a:focus-visible {
  background: #eef5ef;
}

.submodule-list strong {
  color: var(--ink);
}

.submodule-list span {
  color: var(--muted);
}

.route-strip {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--line);
  overflow: hidden;
}

.route-strip a {
  display: grid;
  gap: 0.35rem;
  min-height: 132px;
  padding: 1rem;
  background: rgba(255, 255, 255, 0.82);
  color: inherit;
  text-decoration: none;
}

.route-strip a:hover,
.route-strip a:focus-visible {
  background: #e7efe9;
}

.route-strip span {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: 50%;
  background: var(--green);
  color: var(--white);
  font-weight: 900;
}

.route-strip strong {
  font-size: 1.05rem;
}

.route-strip small {
  color: var(--muted);
  font-weight: 750;
}

.resource-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem;
}

.resource-grid a {
  min-height: 190px;
  padding: 1.1rem;
  border: 1px solid rgba(23, 32, 29, 0.13);
  border-radius: var(--radius);
  background: var(--white);
  color: inherit;
  text-decoration: none;
}

.resource-grid a:hover,
.resource-grid a:focus-visible {
  border-color: var(--green);
  box-shadow: 0 0 0 3px rgba(46, 111, 94, 0.12);
}

.resource-grid h3 {
  margin: 0 0 0.55rem;
}

.resource-grid p {
  margin: 0;
  color: var(--muted);
}

.resource-page {
  width: min(980px, calc(100% - 2rem));
  margin: 0 auto;
  padding: clamp(2rem, 6vw, 5rem) 0;
}

.settings-list {
  display: grid;
  grid-template-columns: minmax(180px, max-content) minmax(0, 1fr);
  gap: 0.6rem 1rem;
  margin: 1rem 0 0;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.settings-list dt {
  font-weight: 900;
}

.settings-list dd {
  margin: 0;
  color: var(--muted);
}

.algorithm-layout {
  display: grid;
  grid-template-columns: minmax(210px, 0.28fr) minmax(0, 0.42fr) minmax(300px, 0.3fr);
  gap: 1rem;
  align-items: stretch;
}

.algorithm-list {
  display: grid;
  align-content: start;
  gap: 0.45rem;
}

.algorithm-button {
  min-height: 44px;
  padding: 0.6rem 0.75rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  color: var(--ink);
  font-weight: 800;
  text-align: left;
  cursor: pointer;
}

.algorithm-button.is-active {
  background: var(--ink);
  color: var(--white);
  border-color: var(--ink);
}

.algorithm-panel,
.algorithm-visual {
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.algorithm-panel {
  min-height: 520px;
  padding: clamp(1rem, 3vw, 1.5rem);
}

.algorithm-panel h3 {
  font-size: clamp(1.5rem, 3vw, 2.2rem);
}

.algorithm-panel ul {
  margin: 1.2rem 0 0;
  padding-left: 1.1rem;
  color: #34413c;
}

.algorithm-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin: 1rem 0;
}

.algorithm-meta span {
  padding: 0.35rem 0.55rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #f7f4eb;
  color: #34413c;
  font-size: 0.82rem;
  font-weight: 800;
}

.algorithm-visual {
  position: relative;
  overflow: hidden;
  min-height: 520px;
  background: #f8f4ea;
}

.knn-playground {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(220px, 0.6fr);
  gap: 1rem;
  align-items: start;
  margin: 1rem 0;
}

.knn-canvas-wrap {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: #f8f4ea;
}

#knnCanvas {
  display: block;
  width: 100%;
  height: auto;
  cursor: crosshair;
  touch-action: none;
}

.knn-controls {
  display: grid;
  gap: 0.6rem;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
  align-self: stretch;
}

.knn-controls label {
  font-weight: 800;
  color: var(--ink);
}

.knn-controls input[type="range"] {
  width: 100%;
}

.knn-readout {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
  min-height: 2.6em;
}

.threshold-playground {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(220px, 0.6fr);
  gap: 1rem;
  align-items: start;
  margin: 1rem 0;
}

.threshold-canvas-wrap {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: #f8f4ea;
}

#thresholdCanvas {
  display: block;
  width: 100%;
  height: auto;
}

.threshold-controls {
  display: grid;
  gap: 0.7rem;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
  align-self: stretch;
}

.threshold-controls label {
  font-weight: 800;
  color: var(--ink);
}

.threshold-controls input[type="range"] {
  width: 100%;
}

.threshold-metrics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.5rem;
  margin: 0;
}

.threshold-metrics div {
  padding: 0.5rem 0.6rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.threshold-metrics dt {
  margin: 0;
  font-size: 0.76rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.threshold-metrics dd {
  margin: 0.15rem 0 0;
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--ink);
}

.tree-playground {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(220px, 0.6fr);
  gap: 1rem;
  align-items: start;
  margin: 1rem 0;
}

.tree-canvas-wrap {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: #f8f4ea;
}

#treeCanvas {
  display: block;
  width: 100%;
  height: auto;
}

.tree-controls {
  display: grid;
  gap: 0.7rem;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
  align-self: stretch;
}

.tree-controls label {
  font-weight: 800;
  color: var(--ink);
}

.tree-controls input[type="range"] {
  width: 100%;
}

.tree-metrics {
  display: grid;
  gap: 0.5rem;
  margin: 0;
}

.tree-metrics div {
  padding: 0.5rem 0.6rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.tree-metrics dt {
  margin: 0;
  font-size: 0.76rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.tree-metrics dd {
  margin: 0.15rem 0 0;
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--ink);
}

.pca-playground {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(220px, 0.6fr);
  gap: 1rem;
  align-items: start;
  margin: 1rem 0;
}

.pca-canvas-wrap {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: #f8f4ea;
}

#pcaCanvas {
  display: block;
  width: 100%;
  height: auto;
}

.pca-controls {
  display: grid;
  gap: 0.7rem;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
  align-self: stretch;
}

.pca-controls label {
  font-weight: 800;
  color: var(--ink);
}

.pca-controls input[type="range"] {
  width: 100%;
}

.pca-metrics {
  display: grid;
  gap: 0.5rem;
  margin: 0;
}

.pca-metrics div {
  padding: 0.5rem 0.6rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.pca-metrics dt {
  margin: 0;
  font-size: 0.76rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.pca-metrics dd {
  margin: 0.15rem 0 0;
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--ink);
}

#algorithmCanvas {
  display: block;
  width: 100%;
  height: 100%;
  min-height: 520px;
}

.workflow-layout {
  display: grid;
  grid-template-columns: minmax(260px, 0.42fr) minmax(0, 0.58fr);
  gap: 1rem;
}

.workflow-layout,
.workflow-steps,
.workflow-panel,
.foundation-card,
.algorithm-layout,
.algorithm-panel,
.algorithm-visual,
.code-shell {
  min-width: 0;
}

.workflow-steps {
  display: grid;
  gap: 0.6rem;
}

.step {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0 0.8rem;
  align-items: center;
  min-height: 88px;
  padding: 0.9rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  color: var(--ink);
  text-align: left;
  cursor: pointer;
}

.step small {
  grid-column: 2;
  color: var(--muted);
}

.step.is-active {
  border-color: var(--green);
  box-shadow: 0 0 0 3px rgba(46, 111, 94, 0.12);
}

.workflow-panel {
  min-height: 380px;
  padding: clamp(1rem, 3vw, 2rem);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

pre {
  position: relative;
  overflow: auto;
  min-width: 0;
  max-width: 100%;
  margin: 1rem 0 0;
  padding: 1rem;
  border-radius: var(--radius);
  background: #18201d;
  color: #f7f1df;
  font-size: 0.9rem;
  line-height: 1.55;
}

pre.copyable-code {
  padding-top: 2.9rem;
}

.pre-copy {
  position: absolute;
  top: 0.55rem;
  right: 0.55rem;
  min-height: 32px;
  padding: 0.35rem 0.6rem;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.08);
  color: #f7f1df;
  font-size: 0.82rem;
  font-weight: 850;
  cursor: pointer;
}

.pre-copy:hover,
.pre-copy:focus-visible {
  background: rgba(255, 255, 255, 0.16);
}

.pre-copy:disabled {
  cursor: default;
  opacity: 0.72;
}

pre code {
  display: block;
  width: max-content;
  min-width: 100%;
}

.recipe-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.tab,
.code-toolbar button {
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  color: var(--ink);
  font-weight: 800;
  cursor: pointer;
}

.tab {
  padding: 0.55rem 0.9rem;
}

.tab.is-active {
  background: var(--ink);
  color: var(--white);
  border-color: var(--ink);
}

.code-shell {
  overflow: hidden;
  border: 1px solid rgba(23, 32, 29, 0.14);
  border-radius: var(--radius);
  background: #18201d;
  box-shadow: var(--shadow);
}

.code-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  color: #f6eddb;
}

.code-toolbar button {
  padding: 0.45rem 0.8rem;
}

.code-shell pre {
  margin: 0;
  border-radius: 0;
}

.checklist-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.75rem;
}

.checklist-grid label {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  min-height: 92px;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  color: #34413c;
  font-weight: 650;
}

.checklist-grid input {
  width: 18px;
  height: 18px;
  margin-top: 0.2rem;
  accent-color: var(--green);
}

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

.deploy-grid article {
  min-height: 230px;
  padding: 1.25rem;
  border: 1px solid rgba(23, 32, 29, 0.12);
  border-radius: var(--radius);
}

dl {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 0.5rem 1rem;
  color: var(--muted);
}

dt {
  color: var(--ink);
  font-weight: 800;
}

dd {
  margin: 0;
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 2rem clamp(1rem, 6vw, 5rem);
  border-top: 1px solid var(--line);
  background: var(--ink);
  color: var(--white);
}

.site-footer p {
  margin: 0.25rem 0 0;
  color: rgba(255, 255, 255, 0.7);
}

@media (max-width: 1080px) {
  .home-hero {
    min-height: auto;
    padding-bottom: clamp(2rem, 7vw, 5rem);
  }

  .home-visual {
    position: relative;
    inset: auto;
    width: 100%;
    min-width: 0;
    height: 360px;
    margin-top: 2rem;
  }

  .hero,
  .workflow-layout,
  .algorithm-layout,
  .course-shell {
    grid-template-columns: 1fr;
  }

  .course-sidebar {
    position: static;
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .timeline {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .foundation-grid,
  .module-grid,
  .promo-grid,
  .deploy-grid,
  .resource-grid,
  .checklist-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .landing-cta {
    grid-template-columns: 1fr;
  }

  .landing-cta .hero-actions {
    justify-content: flex-start;
  }

  .module-group {
    grid-template-columns: 1fr;
  }

  .route-strip {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (max-width: 760px) {
  .topbar {
    min-height: 64px;
  }

  .nav-toggle {
    display: inline-block;
  }

  .site-nav {
    position: fixed;
    top: 64px;
    right: 1rem;
    left: 1rem;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 0.75rem;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: var(--white);
    box-shadow: var(--shadow);
  }

  .site-nav.is-open {
    display: flex;
  }

  .site-nav a {
    width: 100%;
  }

  .module-nav {
    top: 64px;
    flex-wrap: nowrap;
    margin-right: -1rem;
    margin-left: -1rem;
    padding: 0.75rem 1rem;
    overflow-x: auto;
    border-top: 1px solid var(--line);
    scroll-padding-left: 1rem;
  }

  .module-nav a {
    flex: 0 0 auto;
  }

  .hero {
    min-height: auto;
    padding-top: 2rem;
  }

  .home-copy h1 {
    font-size: clamp(2.45rem, 14vw, 4.4rem);
  }

  .home-visual,
  .home-visual #modelCanvas {
    height: 300px;
    min-height: 300px;
  }

  .home-stats,
  .hero-actions {
    display: grid;
    grid-template-columns: 1fr;
  }

  .hero-visual,
  #modelCanvas {
    min-height: 340px;
  }

  .home-visual #modelCanvas {
    min-height: 300px;
  }

  .algorithm-visual,
  #algorithmCanvas {
    min-height: 340px;
  }

  .workflow-layout {
    grid-template-columns: minmax(0, 1fr);
  }

  .workflow-panel pre,
  .deploy-grid pre {
    white-space: pre-wrap;
    overflow-wrap: anywhere;
  }

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

  .timeline,
  .foundation-grid,
  .module-grid,
  .promo-grid,
  .deploy-grid,
  .resource-grid,
  .checklist-grid {
    grid-template-columns: 1fr;
  }

  .promo-grid article {
    min-height: auto;
  }

  .module-group header,
  .submodule-list a {
    grid-template-columns: 1fr;
  }

  .module-group header {
    display: grid;
  }

  .route-strip {
    grid-template-columns: 1fr;
  }

  .settings-list {
    grid-template-columns: 1fr;
  }

  .algorithm-list {
    grid-template-columns: 1fr;
  }

  .timeline article,
  .foundation-card,
  .module-card,
  .deploy-grid article {
    min-height: auto;
  }

  .site-footer {
    display: block;
  }

  .course-sidebar,
  .lesson-grid,
  .visual-panel,
  .knn-playground,
  .threshold-playground,
  .tree-playground,
  .pca-playground {
    grid-template-columns: 1fr;
  }

  .compact-table {
    display: block;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  .compact-table th,
  .compact-table td {
    min-width: 160px;
  }

  .step-list article {
    grid-template-columns: 38px 1fr;
  }

  .step-list span {
    min-width: 38px;
    height: 38px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
  }
}