:root {
  --indigo-50: #eef2ff;
  --indigo-100: #e0e7ff;
  --indigo-200: #c7d2fe;
  --indigo-400: #818cf8;
  --indigo-600: #4f46e5;
  --indigo-800: #3730a3;
  --mint-50: #ecfdf5;
  --mint-700: #047857;
  --amber-50: #fffbeb;
  --amber-700: #b45309;
  --rose-50: #fff1f2;
  --rose-700: #be123c;
  --sky-50: #f0f9ff;
  --sky-700: #0369a1;
  --bg: #f8fafc;
  --card: #ffffff;
  --ink: #1e293b;
  --slate: #475569;
  --mist: #94a3b8;
  --line: #e2e8f0;
  --shadow: 0 4px 24px rgba(30, 41, 59, .08);
  --shadow-hover: 0 8px 40px rgba(30, 41, 59, .14);
  --radius: 20px;
  --radius-sm: 12px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 8% 6%, rgba(199, 210, 254, .7), transparent 28rem),
    radial-gradient(circle at 82% 18%, rgba(236, 253, 245, .8), transparent 24rem),
    var(--bg);
  line-height: 1.75;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(79, 70, 229, .05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(79, 70, 229, .05) 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: linear-gradient(180deg, rgba(0,0,0,.75), transparent 70%);
  z-index: -1;
}

a {
  color: inherit;
}

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  min-height: 64px;
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  background: rgba(255, 255, 255, .9);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: .8rem;
  color: var(--indigo-800);
  font-weight: 800;
  text-decoration: none;
  white-space: nowrap;
}

.brand img {
  width: 142px;
  height: auto;
  display: block;
}

.brand span {
  font-size: .9rem;
}

.nav-links {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: .35rem;
  list-style: none;
  margin: 0;
  padding: 0;
  flex-wrap: wrap;
}

.nav-links a {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
  color: var(--slate);
  font-size: .88rem;
  line-height: 1.2;
  padding: .46rem .78rem;
  border-radius: 999px;
}

.nav-links a:hover {
  color: var(--indigo-800);
  background: var(--indigo-50);
}

.hero {
  padding: 7rem 2rem 4.8rem;
  border-bottom: 1px solid rgba(79, 70, 229, .1);
}

.hero-inner,
.container {
  width: min(1120px, calc(100vw - 2rem));
  margin: 0 auto;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(320px, .9fr);
  gap: 3rem;
  align-items: center;
}

.eyebrow,
.section-label {
  display: inline-flex;
  align-items: center;
  width: fit-content;
  padding: .35rem .85rem;
  border-radius: 999px;
  background: var(--indigo-50);
  color: var(--indigo-800);
  font-size: .76rem;
  font-weight: 800;
  letter-spacing: .08em;
  text-transform: uppercase;
}

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

h1 {
  max-width: 820px;
  margin-bottom: 1.25rem;
  font-size: clamp(2.35rem, 5vw, 4.6rem);
  line-height: 1.08;
  letter-spacing: 0;
}

h2 {
  margin-bottom: .85rem;
  font-size: clamp(1.85rem, 3.5vw, 2.75rem);
  line-height: 1.18;
  letter-spacing: 0;
}

h3 {
  margin-bottom: .55rem;
  font-size: 1.08rem;
  line-height: 1.35;
}

.lead {
  max-width: 720px;
  color: var(--slate);
  font-size: 1.08rem;
}

.hero .lead {
  margin-bottom: 1.75rem;
}

.cta-row {
  display: flex;
  gap: .85rem;
  flex-wrap: wrap;
  align-items: center;
  margin-top: 1.5rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: .78rem 1.35rem;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 800;
  line-height: 1.1;
  border: 1.5px solid transparent;
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: linear-gradient(135deg, var(--indigo-800), var(--indigo-600));
  color: white;
  box-shadow: 0 8px 28px rgba(79, 70, 229, .24);
}

.btn-secondary {
  color: var(--slate);
  background: white;
  border-color: var(--line);
}

.btn-secondary:hover {
  color: var(--indigo-800);
  border-color: var(--indigo-200);
  box-shadow: var(--shadow);
}

.hero-panel {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 28px;
  box-shadow: var(--shadow);
  padding: 2rem;
}

.panel-title {
  color: var(--mist);
  font-size: .78rem;
  font-weight: 800;
  letter-spacing: .1em;
  text-transform: uppercase;
}

.route-list {
  display: grid;
  gap: .85rem;
  margin-top: 1rem;
}

.route-item {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: .85rem;
  align-items: start;
  padding: .95rem;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--bg);
}

.route-num {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 14px;
  background: var(--indigo-100);
  color: var(--indigo-800);
  font-weight: 800;
}

.route-item strong {
  display: block;
  margin-bottom: .1rem;
}

.route-item span {
  display: block;
  color: var(--slate);
  font-size: .9rem;
  line-height: 1.55;
}

section {
  padding: 5.5rem 2rem;
}

section:nth-of-type(even) {
  background: rgba(255, 255, 255, .46);
}

.section-head {
  margin-bottom: 2rem;
}

.section-head .lead {
  margin-bottom: 0;
}

.grid {
  display: grid;
  gap: 1rem;
}

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

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

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

.card,
.module,
.practice,
.table-wrap {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.card {
  padding: 1.45rem;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 4px;
  background: linear-gradient(90deg, var(--indigo-600), var(--indigo-400), var(--mint-700));
  opacity: .7;
}

.card p,
.module p,
.practice p {
  color: var(--slate);
  margin-bottom: 0;
}

.card small {
  display: inline-flex;
  margin-bottom: .75rem;
  color: var(--indigo-800);
  font-size: .72rem;
  font-weight: 800;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.click-card {
  text-decoration: none;
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}

.click-card:hover {
  transform: translateY(-4px);
  border-color: var(--indigo-200);
  box-shadow: var(--shadow-hover);
}

.module {
  padding: 2rem;
  margin-bottom: 1.25rem;
}

.module-header {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  margin-bottom: 1.2rem;
}

.module-mark {
  width: 54px;
  height: 54px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  border-radius: 16px;
  background: var(--indigo-100);
  color: var(--indigo-800);
  font-weight: 800;
}

.module-header p {
  margin-bottom: 0;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr);
  gap: 1.25rem;
  align-items: start;
}

.check-list,
.plain-list {
  display: grid;
  gap: .65rem;
  margin: 1rem 0 0;
  padding: 0;
  list-style: none;
}

.check-list li,
.plain-list li {
  color: var(--slate);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: .85rem .95rem;
}

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

.example-box {
  margin-top: 1rem;
  padding: 1rem;
  border-radius: var(--radius-sm);
  background: var(--indigo-50);
  border: 1px solid var(--indigo-200);
}

.example-box strong,
.note-box strong {
  display: block;
  margin-bottom: .35rem;
  color: var(--ink);
}

.example-box p,
.note-box p {
  margin: 0;
}

.note-box {
  padding: 1rem;
  border-radius: var(--radius-sm);
  background: var(--amber-50);
  border: 1px solid #fde68a;
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: .45rem;
  margin-top: 1rem;
}

.tag {
  display: inline-flex;
  align-items: center;
  padding: .22rem .65rem;
  border-radius: 10px;
  font-size: .75rem;
  font-weight: 800;
  background: var(--indigo-50);
  color: var(--indigo-800);
}

.tag.mint {
  background: var(--mint-50);
  color: var(--mint-700);
}

.tag.amber {
  background: var(--amber-50);
  color: var(--amber-700);
}

.tag.rose {
  background: var(--rose-50);
  color: var(--rose-700);
}

.table-wrap {
  overflow: hidden;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: .93rem;
}

th,
td {
  padding: .9rem 1rem;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line);
}

th {
  color: var(--ink);
  background: var(--indigo-50);
}

td {
  color: var(--slate);
}

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

.practice {
  padding: 1.35rem;
}

.practice h3 {
  margin-bottom: .35rem;
}

.practice .result {
  margin-top: .8rem;
  padding-top: .8rem;
  border-top: 1px solid var(--line);
  color: var(--ink);
  font-weight: 700;
}

.footer {
  padding: 3rem 2rem;
  background: #eef2ff;
  color: var(--slate);
  text-align: center;
}

.footer a {
  color: var(--indigo-800);
  font-weight: 800;
  text-decoration: none;
}

.course-map {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}

.map-node {
  position: relative;
  min-height: 190px;
  padding: 1.25rem;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--card);
  box-shadow: var(--shadow);
  text-decoration: none;
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}

.map-node:hover {
  transform: translateY(-4px);
  border-color: var(--indigo-200);
  box-shadow: var(--shadow-hover);
}

.map-node::after {
  content: "";
  position: absolute;
  top: 2rem;
  right: -1.1rem;
  width: 1.2rem;
  height: 2px;
  background: var(--indigo-200);
}

.map-node:last-child::after {
  display: none;
}

.map-kicker {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 14px;
  background: var(--indigo-100);
  color: var(--indigo-800);
  font-weight: 800;
  margin-bottom: .8rem;
}

.map-node p {
  color: var(--slate);
  margin-bottom: 0;
}

.visual-flow {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: .75rem;
  margin-top: 1.25rem;
}

.flow-step {
  min-height: 118px;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--bg);
  position: relative;
}

.flow-step::after {
  content: ">";
  position: absolute;
  top: 50%;
  right: -.65rem;
  transform: translateY(-50%);
  color: var(--indigo-400);
  font-weight: 800;
}

.flow-step:last-child::after {
  display: none;
}

.flow-step strong {
  display: block;
  margin-bottom: .35rem;
}

.flow-step span {
  display: block;
  color: var(--slate);
  font-size: .88rem;
  line-height: 1.55;
}

.tool-matrix {
  display: grid;
  grid-template-columns: 180px repeat(3, minmax(0, 1fr));
  border: 1px solid var(--line);
  border-radius: 20px;
  overflow: hidden;
  background: var(--card);
  box-shadow: var(--shadow);
}

.matrix-cell {
  min-height: 104px;
  padding: 1rem;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.matrix-cell:nth-child(4n) {
  border-right: 0;
}

.matrix-head {
  background: var(--indigo-50);
  font-weight: 800;
  color: var(--ink);
}

.matrix-cell p {
  margin: .3rem 0 0;
  color: var(--slate);
  font-size: .88rem;
  line-height: 1.5;
}

.playbook {
  display: grid;
  gap: 1rem;
  margin-top: 1.25rem;
}

.play-card {
  display: grid;
  grid-template-columns: 110px minmax(0, 1fr) minmax(240px, .7fr);
  gap: 1rem;
  align-items: stretch;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--card);
  box-shadow: var(--shadow);
}

.play-label {
  display: grid;
  place-items: center;
  border-radius: 16px;
  background: var(--indigo-100);
  color: var(--indigo-800);
  font-weight: 800;
  text-align: center;
  padding: .8rem;
}

.prompt-mini {
  padding: .9rem;
  border-radius: 14px;
  background: #0f172a;
  color: #e2e8f0;
  font-family: "SF Mono", "Fira Code", Consolas, monospace;
  font-size: .82rem;
  line-height: 1.55;
}

.demo-frame {
  border: 1px solid var(--line);
  border-radius: 24px;
  background: var(--card);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.visual-board {
  border: 1px solid var(--line);
  border-radius: 30px;
  background:
    linear-gradient(135deg, rgba(255,255,255,.94), rgba(238,242,255,.92)),
    var(--card);
  box-shadow: var(--shadow-hover);
  padding: 1.2rem;
  overflow: hidden;
}

.board-top {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
  padding: .6rem .75rem 1rem;
  color: var(--slate);
  font-size: .86rem;
}

.board-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: .75rem;
}

.board-card {
  min-height: 130px;
  padding: 1rem;
  border-radius: 20px;
  border: 1px solid rgba(79, 70, 229, .16);
  background: white;
  box-shadow: 0 8px 24px rgba(30, 41, 59, .08);
}

.board-card.big {
  grid-column: span 7;
  min-height: 230px;
}

.board-card.side {
  grid-column: span 5;
}

.board-card.full {
  grid-column: span 12;
}

.board-card h3 {
  margin-bottom: .4rem;
}

.board-card p {
  color: var(--slate);
  margin: 0;
}

.mini-lane {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: .5rem;
  margin-top: 1rem;
}

.mini-step {
  min-height: 72px;
  border-radius: 16px;
  padding: .75rem;
  background: var(--indigo-50);
  color: var(--indigo-800);
  font-weight: 800;
  line-height: 1.3;
}

.mini-step span {
  display: block;
  margin-top: .25rem;
  color: var(--slate);
  font-size: .78rem;
  font-weight: 400;
}

.choice-panel {
  display: grid;
  grid-template-columns: 1.1fr .9fr;
  gap: 1rem;
  align-items: stretch;
}

.task-stack {
  display: grid;
  gap: .65rem;
}

.task-pill {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: .85rem 1rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: white;
  box-shadow: 0 4px 16px rgba(30,41,59,.06);
}

.task-pill b {
  color: var(--ink);
}

.task-pill span {
  color: var(--indigo-800);
  font-size: .84rem;
  font-weight: 800;
}

.tool-orbit {
  min-height: 360px;
  border-radius: 28px;
  background:
    radial-gradient(circle at center, rgba(79,70,229,.14), transparent 6rem),
    linear-gradient(135deg, #ffffff, #eef2ff);
  border: 1px solid var(--line);
  position: relative;
  overflow: hidden;
}

.tool-core {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 132px;
  height: 132px;
  border-radius: 34px;
  display: grid;
  place-items: center;
  text-align: center;
  background: var(--indigo-800);
  color: white;
  font-weight: 800;
  box-shadow: 0 18px 40px rgba(55,48,163,.28);
}

.tool-dot {
  position: absolute;
  min-width: 96px;
  padding: .65rem .8rem;
  border-radius: 999px;
  background: white;
  border: 1px solid var(--indigo-200);
  color: var(--indigo-800);
  font-size: .84rem;
  font-weight: 800;
  text-align: center;
  box-shadow: var(--shadow);
}

.tool-dot:nth-child(2) { left: 8%; top: 12%; }
.tool-dot:nth-child(3) { right: 8%; top: 12%; }
.tool-dot:nth-child(4) { left: 5%; bottom: 18%; }
.tool-dot:nth-child(5) { right: 6%; bottom: 18%; }
.tool-dot:nth-child(6) { left: 50%; top: 8%; transform: translateX(-50%); }
.tool-dot:nth-child(7) { left: 50%; bottom: 8%; transform: translateX(-50%); }

.architecture-canvas {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  padding: 1rem;
  border-radius: 30px;
  border: 1px solid var(--line);
  background: #0f172a;
  box-shadow: var(--shadow-hover);
}

.arch-layer {
  min-height: 180px;
  border-radius: 22px;
  padding: 1.2rem;
  background: rgba(255,255,255,.08);
  border: 1px solid rgba(226,232,240,.18);
  color: #e2e8f0;
}

.arch-layer h3 {
  color: white;
}

.arch-layer p,
.arch-layer li {
  color: #cbd5e1;
}

.arch-layer ul {
  margin: .8rem 0 0;
  padding-left: 1.1rem;
}

.mcp-map {
  display: grid;
  grid-template-columns: 1fr 1.2fr 1fr;
  gap: 1rem;
  align-items: center;
}

.mcp-column {
  display: grid;
  gap: .75rem;
}

.mcp-node {
  padding: .95rem 1rem;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: white;
  box-shadow: var(--shadow);
  font-weight: 800;
}

.mcp-center {
  min-height: 280px;
  display: grid;
  place-items: center;
  border-radius: 32px;
  background: linear-gradient(135deg, var(--indigo-800), var(--indigo-600));
  color: white;
  text-align: center;
  padding: 2rem;
  box-shadow: 0 18px 44px rgba(55,48,163,.28);
}

.mcp-center strong {
  display: block;
  font-size: 2rem;
  line-height: 1.1;
}

.mcp-center span {
  display: block;
  margin-top: .75rem;
  color: rgba(255,255,255,.78);
}

.command-hero {
  min-height: calc(100vh - 64px);
  padding: 6.5rem 2rem 4rem;
  display: grid;
  align-items: center;
  background:
    radial-gradient(circle at 82% 16%, rgba(5, 150, 105, .14), transparent 18rem),
    radial-gradient(circle at 20% 12%, rgba(129, 140, 248, .32), transparent 26rem),
    linear-gradient(180deg, rgba(255,255,255,.78), rgba(238,242,255,.52));
}

.command-layout {
  width: min(1180px, calc(100vw - 2rem));
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, .9fr) minmax(420px, 1.1fr);
  gap: 2rem;
  align-items: center;
}

.command-copy h1 {
  font-size: clamp(2.8rem, 6vw, 5.8rem);
  max-width: 820px;
  margin-bottom: 1.2rem;
}

.command-deck {
  border: 1px solid rgba(79, 70, 229, .18);
  border-radius: 34px;
  background: rgba(255,255,255,.82);
  box-shadow: 0 26px 70px rgba(30,41,59,.16);
  overflow: hidden;
  backdrop-filter: blur(18px);
}

.deck-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 1.15rem;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(135deg, rgba(238,242,255,.95), rgba(255,255,255,.8));
}

.deck-status {
  display: flex;
  align-items: center;
  gap: .45rem;
  color: var(--slate);
  font-size: .82rem;
  font-weight: 800;
}

.deck-status::before {
  content: "";
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--mint-700);
  box-shadow: 0 0 0 6px rgba(4,120,87,.12);
}

.deck-body {
  padding: 1.2rem;
}

.lesson-rail {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: .7rem;
}

.lesson-button {
  border: 1px solid var(--line);
  background: white;
  color: var(--slate);
  border-radius: 18px;
  padding: .85rem;
  min-height: 98px;
  text-align: left;
  font: inherit;
  cursor: pointer;
  transition: transform .2s ease, border-color .2s ease, background .2s ease;
}

.lesson-button strong {
  display: block;
  color: var(--ink);
  margin-bottom: .25rem;
  line-height: 1.25;
}

.lesson-button span {
  display: block;
  font-size: .78rem;
  line-height: 1.45;
}

.lesson-button.active,
.lesson-button:hover {
  transform: translateY(-3px);
  border-color: var(--indigo-400);
  background: var(--indigo-50);
}

.lesson-stage {
  margin-top: 1rem;
  display: grid;
  grid-template-columns: .9fr 1.1fr;
  gap: 1rem;
}

.stage-panel {
  border-radius: 24px;
  border: 1px solid var(--line);
  background: white;
  padding: 1.2rem;
  min-height: 300px;
}

.stage-panel h3 {
  font-size: 1.55rem;
  margin-bottom: .6rem;
}

.stage-panel p {
  color: var(--slate);
}

.stage-link {
  margin-top: 1rem;
  display: inline-flex;
  align-items: center;
  padding: .65rem 1rem;
  border-radius: 999px;
  background: var(--indigo-800);
  color: white;
  text-decoration: none;
  font-weight: 800;
}

.concept-constellation {
  min-height: 300px;
  position: relative;
  border-radius: 26px;
  background:
    radial-gradient(circle at center, rgba(79,70,229,.22), transparent 6rem),
    linear-gradient(135deg, #0f172a, #312e81);
  overflow: hidden;
}

.concept-constellation::before {
  content: "";
  position: absolute;
  inset: 1.4rem;
  border: 1px dashed rgba(226,232,240,.28);
  border-radius: 50%;
}

.concept-core {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 120px;
  height: 120px;
  border-radius: 34px;
  display: grid;
  place-items: center;
  color: white;
  background: rgba(255,255,255,.12);
  border: 1px solid rgba(255,255,255,.24);
  font-weight: 800;
  text-align: center;
}

.concept-chip {
  position: absolute;
  padding: .55rem .75rem;
  border-radius: 999px;
  background: rgba(255,255,255,.92);
  color: var(--indigo-800);
  font-size: .82rem;
  font-weight: 800;
  box-shadow: 0 12px 26px rgba(0,0,0,.16);
}

.concept-chip:nth-child(2) { left: 8%; top: 16%; }
.concept-chip:nth-child(3) { right: 9%; top: 18%; }
.concept-chip:nth-child(4) { left: 9%; bottom: 18%; }
.concept-chip:nth-child(5) { right: 8%; bottom: 18%; }
.concept-chip:nth-child(6) { left: 50%; top: 8%; transform: translateX(-50%); }
.concept-chip:nth-child(7) { left: 50%; bottom: 8%; transform: translateX(-50%); }

.concept-lab {
  display: grid;
  grid-template-columns: minmax(260px, .85fr) minmax(0, 1.15fr);
  gap: 1rem;
  align-items: stretch;
}

.concept-tabs {
  display: grid;
  gap: .65rem;
}

.concept-tab {
  border: 1px solid var(--line);
  background: white;
  border-radius: 18px;
  padding: .95rem 1rem;
  text-align: left;
  font: inherit;
  cursor: pointer;
  color: var(--slate);
}

.concept-tab strong {
  display: block;
  color: var(--ink);
}

.concept-tab.active {
  border-color: var(--indigo-400);
  background: var(--indigo-50);
}

.concept-display {
  border-radius: 26px;
  background: #0f172a;
  color: #e2e8f0;
  padding: 1.4rem;
  min-height: 360px;
  display: grid;
  align-content: center;
  position: relative;
  overflow: hidden;
}

.concept-display::after {
  content: "";
  position: absolute;
  width: 220px;
  height: 220px;
  right: -80px;
  top: -80px;
  border-radius: 50%;
  background: rgba(129,140,248,.22);
}

.concept-display h3 {
  color: white;
  font-size: 2rem;
}

.concept-display p {
  color: #cbd5e1;
  max-width: 60ch;
}

.concept-example {
  margin-top: 1rem;
  padding: 1rem;
  border-radius: 18px;
  background: rgba(255,255,255,.08);
  border: 1px solid rgba(255,255,255,.14);
  color: #e2e8f0;
}

.pathway {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0;
  margin-top: 1.5rem;
  border-radius: 32px;
  overflow: hidden;
  box-shadow: var(--shadow-hover);
}

.pathway a {
  min-height: 260px;
  padding: 1.4rem;
  background: white;
  border-right: 1px solid var(--line);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.pathway a:nth-child(2) { background: var(--indigo-50); }
.pathway a:nth-child(3) { background: #eefcf6; }
.pathway a:nth-child(4) { background: var(--amber-50); border-right: 0; }

.pathway a::after {
  content: attr(data-step);
  position: absolute;
  right: -10px;
  bottom: -28px;
  font-size: 7rem;
  line-height: 1;
  font-weight: 800;
  color: rgba(79,70,229,.11);
}

.pathway h3 {
  font-size: 1.35rem;
  max-width: 11rem;
}

.pathway p {
  color: var(--slate);
  position: relative;
  z-index: 1;
}

.teaching-card {
  display: grid;
  grid-template-columns: minmax(220px, .55fr) minmax(0, 1.45fr);
  gap: 1rem;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: 28px;
  background: white;
  box-shadow: var(--shadow);
  margin-bottom: 1rem;
}

.teaching-cover {
  min-height: 260px;
  border-radius: 22px;
  padding: 1.2rem;
  color: white;
  background:
    radial-gradient(circle at 80% 20%, rgba(255,255,255,.25), transparent 7rem),
    linear-gradient(135deg, var(--indigo-800), var(--indigo-600));
  display: grid;
  align-content: space-between;
}

.teaching-cover .tool-name {
  font-size: 1.5rem;
  line-height: 1.15;
  font-weight: 800;
}

.teaching-cover .tool-type {
  width: fit-content;
  padding: .3rem .7rem;
  border-radius: 999px;
  background: rgba(255,255,255,.16);
  border: 1px solid rgba(255,255,255,.25);
  font-size: .78rem;
  font-weight: 800;
}

.teaching-body {
  display: grid;
  gap: 1rem;
}

.teaching-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: .75rem;
}

.teach-step {
  min-height: 128px;
  padding: .9rem;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: var(--bg);
}

.teach-step strong {
  display: block;
  margin-bottom: .35rem;
  color: var(--ink);
}

.teach-step p {
  margin: 0;
  color: var(--slate);
  font-size: .88rem;
  line-height: 1.5;
}

.architecture-strip {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: .55rem;
  padding: .85rem;
  border-radius: 22px;
  background: #0f172a;
}

.architecture-strip div {
  min-height: 90px;
  padding: .8rem;
  border-radius: 16px;
  background: rgba(255,255,255,.08);
  border: 1px solid rgba(255,255,255,.12);
  color: #e2e8f0;
  font-size: .86rem;
  line-height: 1.45;
}

.architecture-strip strong {
  display: block;
  color: white;
  margin-bottom: .25rem;
}

.demo-toolbar {
  display: flex;
  gap: .4rem;
  align-items: center;
  padding: .8rem 1rem;
  background: var(--indigo-50);
  border-bottom: 1px solid var(--line);
}

.demo-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--indigo-400);
}

.demo-body {
  padding: 1rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: .85rem;
}

.demo-pane {
  min-height: 160px;
  padding: 1rem;
  border-radius: 16px;
  background: var(--bg);
  border: 1px solid var(--line);
}

.demo-pane strong {
  display: block;
  margin-bottom: .5rem;
}

.demo-pane p {
  margin: 0;
  color: var(--slate);
}

@media (max-width: 900px) {
  .nav {
    align-items: flex-start;
    flex-direction: column;
    padding: .85rem 1rem;
  }

  .nav-links {
    justify-content: flex-start;
  }

  .hero {
    padding-top: 4rem;
  }

  .hero-grid,
  .command-layout,
  .split,
  .grid-2,
  .grid-3,
  .grid-4,
  .course-map,
  .visual-flow,
  .play-card,
  .demo-body,
  .choice-panel,
  .architecture-canvas,
  .mcp-map,
  .lesson-stage,
  .concept-lab,
  .pathway,
  .teaching-card,
  .teaching-grid,
  .architecture-strip {
    grid-template-columns: 1fr;
  }

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

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

  .board-card.big,
  .board-card.side,
  .board-card.full {
    grid-column: span 1;
  }

  .mini-lane {
    grid-template-columns: 1fr 1fr;
  }

  .map-node::after,
  .flow-step::after {
    display: none;
  }

  .tool-matrix {
    grid-template-columns: 1fr;
  }

  .matrix-cell,
  .matrix-cell:nth-child(4n) {
    border-right: 0;
  }

  .hero-panel,
  .module {
    padding: 1.35rem;
  }
}

@media (max-width: 560px) {
  section {
    padding: 4rem 1rem;
  }

  .hero {
    padding-left: 1rem;
    padding-right: 1rem;
  }

  .brand img {
    width: 128px;
  }

  .nav-links a {
    padding: .38rem .55rem;
    font-size: .82rem;
  }

  .module-header {
    flex-direction: column;
  }
}