:root {
  color-scheme: light;
  --paper: #f3f4ef;
  --paper-strong: #e7e9e1;
  --ink: #151b1a;
  --muted: #626a66;
  --line: #c9cec6;
  --into: #d94f3d;
  --for: #2f7c71;
  --through: #5368aa;
  --panel: #fbfcf8;
  --shadow: 0 18px 50px rgba(21, 27, 26, 0.1);
  font-family: Inter, "Noto Sans SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.6;
}

button,
a {
  font: inherit;
}

button {
  color: inherit;
}

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

button:focus-visible,
a:focus-visible {
  outline: 3px solid var(--ink);
  outline-offset: 4px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
  padding: 0 4vw;
  border-bottom: 1px solid var(--line);
  background: rgba(243, 244, 239, 0.94);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 0.76rem;
  font-weight: 800;
}

.brand-mark {
  display: flex;
  align-items: flex-end;
  gap: 3px;
  width: 22px;
  height: 20px;
}

.brand-mark i {
  display: block;
  width: 5px;
  height: 10px;
  background: var(--into);
}

.brand-mark i:nth-child(2) {
  height: 16px;
  background: var(--for);
}

.brand-mark i:nth-child(3) {
  height: 20px;
  background: var(--through);
}

nav {
  display: flex;
  align-items: center;
  gap: 28px;
  font-size: 0.82rem;
  color: var(--muted);
}

nav a {
  padding: 8px 0;
  border-bottom: 1px solid transparent;
}

nav a:hover {
  color: var(--ink);
  border-color: var(--ink);
}

main {
  overflow: hidden;
}

.atlas-section,
.compare-section,
.practice-section {
  padding: 72px 4vw 84px;
}

.section-heading {
  width: min(1380px, 100%);
  margin: 0 auto 40px;
}

.section-heading.compact {
  margin-bottom: 32px;
}

.eyebrow,
.detail-kicker,
.step-label {
  margin: 0 0 10px;
  font-size: 0.72rem;
  font-weight: 800;
  line-height: 1.2;
}

.eyebrow {
  color: var(--for);
}

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

h1,
.section-heading h2 {
  max-width: 920px;
  margin-bottom: 12px;
  font-family: Georgia, "Songti SC", serif;
  font-weight: 500;
  line-height: 1.08;
}

h1 {
  font-size: clamp(2.7rem, 5.5vw, 5.8rem);
}

.section-heading h2 {
  font-size: clamp(2rem, 3.4vw, 3.6rem);
}

.lede {
  max-width: 720px;
  margin-bottom: 0;
  color: var(--muted);
  font-size: 1rem;
}

.atlas-workspace {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(340px, 0.8fr);
  width: min(1380px, 100%);
  min-height: 650px;
  margin: 0 auto;
  border: 1px solid var(--line);
  background: var(--panel);
  box-shadow: var(--shadow);
}

.map-column {
  display: flex;
  min-width: 0;
  flex-direction: column;
  padding: 24px 30px 30px;
  background-color: #eceee8;
  background-image:
    linear-gradient(rgba(21, 27, 26, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(21, 27, 26, 0.045) 1px, transparent 1px);
  background-size: 28px 28px;
}

.map-legend {
  display: flex;
  gap: 22px;
  color: var(--muted);
  font-size: 0.72rem;
}

.map-legend span {
  display: inline-flex;
  align-items: center;
  gap: 7px;
}

.legend-line {
  width: 24px;
  border-top: 1px solid var(--muted);
}

.legend-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--into);
}

.map-stage {
  position: relative;
  width: min(100%, 800px);
  aspect-ratio: 10 / 7;
  min-height: 520px;
  margin: auto;
}

.relation-map {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  overflow: visible;
}

.orbit,
.spoke {
  fill: none;
  vector-effect: non-scaling-stroke;
}

.orbit {
  stroke: #939b96;
  stroke-width: 1.5;
  stroke-dasharray: 7 8;
  animation: path-flow 14s linear infinite;
}

.arrow-head {
  fill: #939b96;
}

.spoke {
  stroke: #bcc2bd;
  stroke-width: 1;
}

.map-stage[data-active="into"] .spoke-into,
.map-stage[data-active="for"] .spoke-for,
.map-stage[data-active="through"] .spoke-through {
  stroke-width: 3;
}

.map-stage[data-active="into"] .spoke-into {
  stroke: var(--into);
}

.map-stage[data-active="for"] .spoke-for {
  stroke: var(--for);
}

.map-stage[data-active="through"] .spoke-through {
  stroke: var(--through);
}

@keyframes path-flow {
  to {
    stroke-dashoffset: -120;
  }
}

.paradigm-node {
  position: absolute;
  z-index: 4;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  width: 164px;
  aspect-ratio: 1;
  padding: 20px;
  border: 1px solid var(--ink);
  border-radius: 50%;
  background: var(--panel);
  text-align: left;
  cursor: pointer;
  transition: color 180ms ease, background 180ms ease, transform 180ms ease, box-shadow 180ms ease;
}

.paradigm-node:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 25px rgba(21, 27, 26, 0.12);
}

.paradigm-node strong {
  margin: 8px 0 2px;
  font-family: Georgia, serif;
  font-size: 2rem;
  line-height: 1;
}

.node-through strong {
  font-size: 1.55rem;
}

.paradigm-node > span:last-child {
  font-size: 0.76rem;
}

.node-index {
  font-size: 0.66rem;
  font-weight: 800;
}

.node-into {
  top: 4%;
  left: 7%;
}

.node-for {
  top: 4%;
  right: 7%;
}

.node-through {
  bottom: 2%;
  left: 50%;
  transform: translateX(-50%);
}

.node-through:hover {
  transform: translate(-50%, -4px);
}

.node-into.is-active {
  color: #fff;
  border-color: var(--into);
  background: var(--into);
}

.node-for.is-active {
  color: #fff;
  border-color: var(--for);
  background: var(--for);
}

.node-through.is-active {
  color: #fff;
  border-color: var(--through);
  background: var(--through);
}

.map-center {
  position: absolute;
  z-index: 3;
  top: 46%;
  left: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 144px;
  aspect-ratio: 1;
  transform: translate(-50%, -50%);
  flex-direction: column;
  border: 1px solid var(--ink);
  border-radius: 50%;
  background: var(--ink);
  color: #fff;
}

.map-center span,
.map-center small {
  font-size: 0.58rem;
  font-weight: 700;
}

.map-center strong {
  font-family: Georgia, serif;
  font-size: 1.1rem;
}

.relation-label {
  position: absolute;
  z-index: 2;
  padding: 2px 7px;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--muted);
  font-size: 0.62rem;
}

.label-framing {
  top: 4%;
  left: 50%;
  transform: translateX(-50%);
}

.label-guiding {
  top: 49%;
  right: 8%;
}

.label-reflecting {
  top: 49%;
  left: 8%;
}

.detail-panel {
  min-width: 0;
  padding: 34px clamp(24px, 3vw, 44px);
  border-left: 1px solid var(--line);
  background: var(--panel);
}

.detail-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}

.detail-kicker {
  color: var(--into);
}

.direction-badge {
  flex: 0 0 auto;
  padding: 4px 8px;
  border: 1px solid currentColor;
  border-radius: 2px;
  color: var(--muted);
  font-size: 0.68rem;
}

.detail-panel h2 {
  margin: 14px 0 12px;
  font-family: Georgia, "Songti SC", serif;
  font-size: clamp(1.8rem, 2.5vw, 2.8rem);
  font-weight: 500;
  line-height: 1.15;
}

.detail-summary {
  margin-bottom: 24px;
  color: var(--muted);
  font-size: 0.92rem;
}

.detail-facts {
  margin: 0;
  border-top: 1px solid var(--line);
}

.detail-facts > div {
  display: grid;
  grid-template-columns: 76px 1fr;
  gap: 12px;
  padding: 13px 0;
  border-bottom: 1px solid var(--line);
}

.detail-facts dt {
  color: var(--muted);
  font-size: 0.72rem;
}

.detail-facts dd {
  margin: 0;
  font-size: 0.82rem;
}

.step-browser {
  margin-top: 24px;
}

.step-label {
  color: var(--muted);
}

.step-tabs {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border: 1px solid var(--line);
}

.step-tabs button {
  min-width: 0;
  min-height: 42px;
  padding: 8px 6px;
  border: 0;
  border-right: 1px solid var(--line);
  background: transparent;
  font-size: 0.74rem;
  cursor: pointer;
}

.step-tabs button:last-child {
  border-right: 0;
}

.step-tabs button[aria-selected="true"] {
  background: var(--ink);
  color: #fff;
}

.step-content {
  min-height: 94px;
  padding: 16px 0 4px;
}

.step-content h3 {
  margin-bottom: 5px;
  font-size: 0.92rem;
}

.step-content p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 0.82rem;
}

.example-block {
  display: grid;
  grid-template-columns: 76px 1fr;
  gap: 12px;
  margin-top: 18px;
  padding-top: 16px;
  border-top: 1px solid var(--ink);
}

.example-block span {
  color: var(--muted);
  font-size: 0.72rem;
}

.example-block p {
  margin: 0;
  font-size: 0.82rem;
}

.compare-section {
  background: var(--ink);
  color: #f7f8f4;
}

.compare-section .eyebrow {
  color: #80c9bd;
}

.comparison-table {
  width: min(1380px, 100%);
  margin: 0 auto;
  border-top: 1px solid #505754;
}

.comparison-row {
  display: grid;
  grid-template-columns: 0.72fr repeat(3, 1fr);
  border-bottom: 1px solid #505754;
}

.comparison-row > * {
  min-width: 0;
  padding: 20px 22px;
  border-right: 1px solid #505754;
  font-size: 0.86rem;
}

.comparison-row > *:last-child {
  border-right: 0;
}

.comparison-row > [role="rowheader"] {
  color: #aeb5b1;
}

.comparison-header > div {
  color: #aeb5b1;
  font-size: 0.72rem;
}

.comparison-header button {
  border-top: 0;
  border-bottom: 0;
  border-left: 0;
  background: transparent;
  color: #fff;
  text-align: left;
  cursor: pointer;
}

.comparison-header button:hover {
  background: #252c2a;
}

.comparison-header button span {
  display: block;
  margin-top: 2px;
  color: #aeb5b1;
  font-size: 0.68rem;
}

.practice-section {
  background: #dde8e4;
}

.practice-flow {
  width: min(1380px, 100%);
  margin: 0 auto;
  padding: 0;
  border-top: 1px solid #98aaa4;
  list-style: none;
}

.practice-flow li {
  display: grid;
  grid-template-columns: 160px minmax(0, 1fr) 150px;
  align-items: center;
  gap: 30px;
  min-height: 142px;
  border-bottom: 1px solid #98aaa4;
}

.flow-no {
  align-self: start;
  padding-top: 34px;
  font-size: 0.72rem;
  font-weight: 800;
}

.practice-flow h3 {
  margin-bottom: 7px;
  font-size: 1.15rem;
}

.practice-flow p {
  max-width: 740px;
  margin-bottom: 0;
  color: #4e5e59;
  font-size: 0.9rem;
}

.flow-output {
  justify-self: end;
  padding: 7px 10px;
  border: 1px solid #70847d;
  border-radius: 2px;
  font-size: 0.72rem;
}

footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 26px 4vw;
  background: #fff;
  color: var(--muted);
  font-size: 0.68rem;
}

@media (max-width: 1040px) {
  .atlas-workspace {
    grid-template-columns: 1fr;
  }

  .map-column {
    min-height: 650px;
  }

  .detail-panel {
    border-top: 1px solid var(--line);
    border-left: 0;
  }
}

@media (max-width: 720px) {
  .site-header {
    min-height: 56px;
    padding: 0 18px;
  }

  .brand > span:last-child {
    display: none;
  }

  nav {
    gap: 16px;
    font-size: 0.75rem;
  }

  .atlas-section,
  .compare-section,
  .practice-section {
    padding: 50px 18px 60px;
  }

  .section-heading {
    margin-bottom: 28px;
  }

  h1 {
    font-size: 2.65rem;
  }

  .atlas-workspace {
    width: 100%;
  }

  .map-column {
    min-height: 590px;
    padding: 18px 12px 24px;
  }

  .map-legend {
    padding-left: 6px;
  }

  .map-stage {
    min-height: 500px;
  }

  .paradigm-node {
    width: 118px;
    padding: 14px;
  }

  .paradigm-node strong {
    margin-top: 5px;
    font-size: 1.35rem;
  }

  .node-through strong {
    font-size: 1rem;
  }

  .paradigm-node > span:last-child {
    font-size: 0.65rem;
  }

  .node-into {
    top: 8%;
    left: 1%;
  }

  .node-for {
    top: 8%;
    right: 1%;
  }

  .node-through {
    bottom: 8%;
  }

  .map-center {
    width: 112px;
  }

  .label-framing {
    top: 4%;
  }

  .label-guiding {
    top: 51%;
    right: 1%;
  }

  .label-reflecting {
    top: 51%;
    left: 1%;
  }

  .detail-panel {
    padding: 26px 20px 30px;
  }

  .detail-head {
    display: block;
  }

  .direction-badge {
    display: inline-block;
    margin-top: 4px;
  }

  .comparison-table {
    overflow: visible;
  }

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

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

  .comparison-header > div {
    display: none;
  }

  .comparison-header button {
    padding: 14px 10px;
    border-right: 1px solid #505754;
  }

  .comparison-row:not(.comparison-header) > * {
    border-right: 0;
  }

  .comparison-row:not(.comparison-header) > [role="rowheader"] {
    padding: 18px 12px 8px;
    color: #fff;
    font-weight: 700;
  }

  .comparison-row:not(.comparison-header) > [role="cell"] {
    display: grid;
    grid-template-columns: 74px 1fr;
    gap: 12px;
    padding: 9px 12px;
  }

  .comparison-row:not(.comparison-header) > [role="cell"]::before {
    content: attr(data-label);
    color: #8fd2c7;
    font-size: 0.68rem;
    font-weight: 800;
  }

  .comparison-row:not(.comparison-header) > [role="cell"]:last-child {
    padding-bottom: 20px;
  }

  .practice-flow li {
    grid-template-columns: 1fr;
    gap: 8px;
    padding: 24px 0;
  }

  .flow-no {
    padding-top: 0;
  }

  .flow-output {
    justify-self: start;
    margin-top: 8px;
  }

  footer {
    flex-direction: column;
  }
}

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

  .orbit {
    animation: none;
  }

  .paradigm-node {
    transition: none;
  }
}