/* MYW concept observatory — one manuscript, observed from two worlds. */
.concept-page {
  min-height: 100vh;
  overflow-x: clip;
  color: var(--ink);
  background: var(--void);
  transition: color .46s var(--ease-world), background-color .46s var(--ease-world);
}

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

.concept-page::before {
  content: "";
  position: fixed;
  inset: var(--nav-h) 0 0;
  pointer-events: none;
  opacity: .42;
  background-image:
    linear-gradient(90deg, transparent calc(var(--page-gutter) - 1px), var(--hair2) var(--page-gutter), transparent calc(var(--page-gutter) + 1px)),
    linear-gradient(var(--hair2) 1px, transparent 1px);
  background-size: 100% 100%, 100% 12rem;
  mask-image: linear-gradient(to bottom, #000, transparent 78%);
}

.concept-progress {
  position: fixed;
  z-index: 44;
  top: var(--nav-h);
  left: 0;
  width: calc(var(--read-progress, 0) * 1%);
  height: 1px;
  background: var(--seal);
  transform-origin: left;
  pointer-events: none;
}

.concept-shell {
  position: relative;
  width: min(100%, 94rem);
  margin: 0 auto;
  padding: clamp(5.2rem, 9vw, 9rem) var(--page-gutter) 8rem;
}

.concept-hero {
  min-height: min(52rem, 72svh);
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(16rem, .55fr);
  align-items: end;
  gap: clamp(3rem, 8vw, 9rem);
  padding: 3rem 0 clamp(5rem, 10vw, 9rem);
  border-bottom: 1px solid var(--hair);
}
.concept-hero > *,
.concept-hero__aside { min-width: 0; }

.concept-kicker,
.concept-code,
.concept-status,
.concept-side-index,
.concept-term small,
.concept-step small,
.concept-footnote {
  font: 600 var(--fs-label)/1.45 var(--mono);
  letter-spacing: var(--tracking-label);
  text-transform: uppercase;
}

.concept-kicker {
  margin: 0 0 1.4rem;
  color: var(--seal);
}

.concept-hero h1 {
  max-width: 10ch;
  margin: 0;
  font: 500 clamp(4.4rem, 11vw, 10.8rem)/.9 var(--mincho);
  letter-spacing: -.055em;
  color: var(--ink);
}
.concept-hero h1 [lang] { color: inherit; }

.concept-hero h1 ruby { ruby-position: over; }
.concept-hero h1 rt {
  font: 600 .09em/1 var(--mono);
  letter-spacing: .16em;
  color: var(--faint);
}

.concept-lede {
  max-width: 38rem;
  margin: 2.4rem 0 0;
  font: 400 var(--fs-lede)/1.9 var(--sf);
  color: var(--dim);
}

.concept-hero__aside {
  align-self: stretch;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding-left: 1.5rem;
  border-left: 1px solid var(--hair);
}

.concept-code { color: var(--faint); overflow-wrap: anywhere; }
.concept-axiom {
  margin: auto 0 0;
  padding-top: 4rem;
  font: 500 clamp(1.35rem, 2.1vw, 2.15rem)/1.5 var(--mincho);
}
.concept-axiom em { color: var(--seal); font-style: normal; }

.concept-status {
  display: inline-flex;
  align-items: center;
  gap: .65rem;
  width: fit-content;
  margin-top: 1.4rem;
  color: var(--dim);
}
.concept-status::before {
  content: "";
  width: .48rem;
  height: .48rem;
  border: 1px solid currentColor;
  transform: rotate(45deg);
}
.concept-status[data-status="locked"] { color: var(--celadon); }
.concept-status[data-status="direction"] { color: var(--seal); }
.concept-status[data-status="open"] { color: var(--murmur); }

.concept-layout {
  display: grid;
  grid-template-columns: 13rem minmax(0, 1fr);
  gap: clamp(2rem, 6vw, 7rem);
  padding-top: clamp(5rem, 9vw, 9rem);
}

.concept-side {
  position: relative;
}
.concept-side__inner {
  position: sticky;
  top: calc(var(--nav-h) + 2.2rem);
}
.concept-side-index { color: var(--faint); }
.concept-side nav {
  display: grid;
  margin-top: 1.4rem;
  border-top: 1px solid var(--hair);
}
.concept-side a {
  position: relative;
  padding: .85rem 1.4rem .85rem 0;
  color: var(--dim);
  border-bottom: 1px solid var(--hair2);
  text-decoration: none;
  font: 500 var(--fs-small)/1.45 var(--sf);
  transition: color .16s ease, padding-left .16s ease;
}
.concept-side a::after {
  content: "↘";
  position: absolute;
  right: 0;
  color: var(--faint);
}
.concept-side a:hover,
.concept-side a:focus-visible { color: var(--ink); padding-left: .35rem; }

.concept-content { min-width: 0; }
.concept-section {
  scroll-margin-top: calc(var(--nav-h) + 2rem);
  padding: 0 0 clamp(5rem, 9vw, 9rem);
}
.concept-section + .concept-section {
  padding-top: clamp(5rem, 8vw, 8rem);
  border-top: 1px solid var(--hair);
}

.concept-section__head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(12rem, .42fr);
  gap: 2rem;
  align-items: end;
  margin-bottom: clamp(2.5rem, 5vw, 4.5rem);
}
.concept-section h2 {
  margin: 0;
  font: 500 clamp(2.5rem, 5.3vw, 5.6rem)/1.05 var(--mincho);
  letter-spacing: -.035em;
}
.concept-section__head p {
  margin: 0;
  color: var(--dim);
  font: 400 var(--fs-body)/1.8 var(--sf);
}

.concept-definitions {
  border-top: 1px solid var(--hair);
}
.concept-term {
  display: grid;
  grid-template-columns: minmax(12rem, .8fr) minmax(0, 1.8fr) auto;
  gap: clamp(1.2rem, 3vw, 3rem);
  align-items: start;
  padding: 1.6rem 0 1.8rem;
  border-bottom: 1px solid var(--hair);
}
.concept-term h3 {
  margin: 0;
  font: 500 clamp(1.35rem, 2.5vw, 2.35rem)/1.2 var(--mincho);
}
.concept-term h3 span {
  display: block;
  margin-top: .3rem;
  color: var(--faint);
  font: 500 var(--fs-small)/1.4 var(--mono);
  letter-spacing: .08em;
}
.concept-term p {
  max-width: 50rem;
  margin: 0;
  color: var(--dim);
  font: 400 var(--fs-body)/1.85 var(--sf);
}

.concept-diagram {
  position: relative;
  padding: clamp(2rem, 5vw, 4rem) 0;
  border-block: 1px solid var(--hair);
}
.concept-tree {
  display: grid;
  gap: .6rem;
  max-width: 58rem;
  margin: 0 auto;
}
.concept-tree__node {
  position: relative;
  display: grid;
  grid-template-columns: 7rem minmax(0, 1fr) auto;
  gap: 1.4rem;
  align-items: baseline;
  padding: 1rem 0;
  color: var(--ink);
  border-bottom: 1px solid var(--hair2);
  text-decoration: none;
}
.concept-tree__node::before {
  content: "";
  position: absolute;
  left: calc(var(--tree-depth, 0) * 2rem);
  bottom: -1px;
  width: 2rem;
  border-bottom: 1px solid var(--seal);
}
.concept-tree__node small { color: var(--faint); font: 600 var(--fs-label)/1 var(--mono); }
.concept-tree__node b { font: 500 clamp(1rem, 1.8vw, 1.4rem)/1.4 var(--mincho); }
.concept-tree__node span { color: var(--dim); font: 400 var(--fs-small)/1.5 var(--sf); }
.concept-tree__node:hover b,
.concept-tree__node:focus-visible b { color: var(--seal); }

.dimension-crossing {
  position: relative;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  margin: 3rem 0 0;
  border: 1px solid var(--hair);
}
.dimension-crossing::before {
  content: "";
  position: absolute;
  left: 50%;
  top: -3rem;
  bottom: -3rem;
  border-left: 1px solid var(--seal);
  opacity: .7;
}
.dimension-crossing div { padding: clamp(1.3rem, 3vw, 2.5rem); }
.dimension-crossing div + div { border-left: 1px solid var(--hair); }
.dimension-crossing b { display: block; font: 500 clamp(1.6rem, 3vw, 3rem)/1 var(--mincho); }
.dimension-crossing span { display: block; margin-top: .7rem; color: var(--dim); font: 500 var(--fs-small)/1.4 var(--mono); }

.concept-flow {
  display: grid;
  grid-template-columns: repeat(var(--flow-columns, 4), minmax(0, 1fr));
  border-block: 1px solid var(--hair);
}
.concept-step {
  position: relative;
  min-height: 13rem;
  padding: 1.5rem 1.4rem 2rem;
}
.concept-step + .concept-step { border-left: 1px solid var(--hair); }
.concept-step:not(:last-child)::after {
  content: "→";
  position: absolute;
  z-index: 2;
  top: 50%;
  right: 0;
  transform: translate(52%, -50%);
  padding: .25rem;
  color: var(--seal);
  background: var(--void);
}
.concept-step small { color: var(--faint); }
.concept-step b {
  display: block;
  margin-top: 2.2rem;
  font: 500 clamp(1.15rem, 2vw, 1.75rem)/1.35 var(--mincho);
}
.concept-step p { margin: .7rem 0 0; color: var(--dim); font: 400 var(--fs-small)/1.65 var(--sf); }

.concept-split {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-block: 1px solid var(--hair);
}
.concept-split > section { padding: clamp(1.8rem, 4vw, 3.6rem); }
.concept-split > section + section { border-left: 1px solid var(--hair); }
.concept-split h3 { margin: 0; font: 500 var(--fs-h3)/1.2 var(--mincho); }
.concept-split p,
.concept-split li { color: var(--dim); font: 400 var(--fs-body)/1.78 var(--sf); }
.concept-split ul { margin: 1.3rem 0 0; padding-left: 1.1rem; }

.concept-callout {
  display: grid;
  grid-template-columns: .3fr 1fr;
  gap: clamp(1.5rem, 4vw, 4rem);
  margin-top: 2rem;
  padding: clamp(2rem, 4vw, 3.5rem) 0;
  border-block: 1px solid var(--hair);
}
.concept-callout b { color: var(--seal); font: 600 var(--fs-label)/1.5 var(--mono); letter-spacing: var(--tracking-label); }
.concept-callout p { margin: 0; font: 500 clamp(1.25rem, 2.2vw, 2rem)/1.6 var(--mincho); }

.concept-filter {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
  margin-bottom: 2rem;
}
.concept-filter button {
  min-height: 2.65rem;
  padding: .65rem 1rem;
  color: var(--dim);
  background: transparent;
  border: 1px solid var(--hair);
  border-radius: 0;
  font: 600 var(--fs-label)/1 var(--mono);
  letter-spacing: .1em;
  cursor: pointer;
  transition: color .14s ease, border-color .14s ease, transform .1s ease;
}
.concept-filter button:hover,
.concept-filter button[aria-pressed="true"] { color: var(--ink); border-color: var(--seal); }
.concept-filter button:active { transform: scale(.975); }

.concept-index-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--hair);
}
.concept-index-card {
  position: relative;
  container-type: inline-size;
  min-height: 23rem;
  display: flex;
  flex-direction: column;
  padding: 1.6rem;
  color: var(--ink);
  border-right: 1px solid var(--hair);
  border-bottom: 1px solid var(--hair);
  text-decoration: none;
  transition: background-color .18s ease, transform .12s ease;
}
.concept-index-card:nth-child(3n + 1) { border-left: 1px solid var(--hair); }
.concept-index-card:hover,
.concept-index-card:focus-visible { background: color-mix(in srgb, var(--reading-strong) 70%, transparent); }
.concept-index-card:active { transform: scale(.992); }
.concept-index-card[hidden] { display: none; }
.concept-index-card__no { color: var(--faint); font: 600 var(--fs-label)/1 var(--mono); }
.concept-index-card h3 {
  display: flex;
  align-items: flex-end;
  min-height: 2.1em;
  margin: auto 0 0;
  font: 500 1.8rem/1.05 var(--mincho);
  letter-spacing: -.025em;
  overflow-wrap: anywhere;
  word-break: normal;
}
.concept-index-card h3.mw-display-title {
  display: grid;
  align-content: end;
  align-items: start;
  gap: 0;
  width: 100%;
  word-break: normal;
}
.concept-index-card h3.mw-display-title .mw-display-title__cjk {
  width: 100%;
  overflow-wrap: anywhere;
  word-break: normal;
}

@container (min-width: 17rem) {
  .concept-index-card h3 { font-size: 2.2rem; }
}
.concept-index-card p { margin: 1rem 0 0; color: var(--dim); font: 400 var(--fs-small)/1.7 var(--sf); }
.concept-index-card__arrow { position: absolute; top: 1.4rem; right: 1.4rem; color: var(--seal); }

.concept-open-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--hair);
}
.concept-open-list article { padding: 1.5rem 0 2rem; border-bottom: 1px solid var(--hair); }
.concept-open-list article:nth-child(odd) { padding-right: 2rem; }
.concept-open-list article:nth-child(even) { padding-left: 2rem; border-left: 1px solid var(--hair); }
.concept-open-list h3 { margin: 0; font: 500 var(--fs-h3)/1.3 var(--mincho); }
.concept-open-list p { margin: .65rem 0 0; color: var(--dim); font: 400 var(--fs-small)/1.7 var(--sf); }

.concept-footer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 2rem;
  align-items: end;
  padding-top: 3rem;
  border-top: 1px solid var(--hair);
}
.concept-footer p { max-width: 48rem; margin: 0; color: var(--faint); font: 400 var(--fs-small)/1.7 var(--sf); }
.concept-footer a { color: var(--ink); text-decoration: none; font: 600 var(--fs-label)/1 var(--mono); letter-spacing: .12em; }

.tri > [lang] { display: none; }
html[lang="ja"] .tri > [lang="ja"],
html[lang="zh"] .tri > [lang="zh"],
html[lang="en"] .tri > [lang="en"] { display: contents; }

.concept-page a:focus-visible,
.concept-page button:focus-visible,
.concept-page summary:focus-visible { outline: var(--focus-ring); outline-offset: 4px; }

@media (max-width: 980px) {
  .concept-hero { grid-template-columns: 1fr; min-height: auto; }
  .concept-hero__aside { min-height: 16rem; }
  .concept-layout { grid-template-columns: 1fr; }
  .concept-side__inner { position: static; }
  .concept-side nav { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .concept-side a:nth-child(odd) { border-right: 1px solid var(--hair2); }
  .concept-index-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .concept-index-card:nth-child(3n + 1) { border-left: 0; }
  .concept-index-card:nth-child(2n + 1) { border-left: 1px solid var(--hair); }
  .concept-flow { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .concept-step:nth-child(3) { border-left: 0; border-top: 1px solid var(--hair); }
  .concept-step:nth-child(4) { border-top: 1px solid var(--hair); }
  .concept-step:nth-child(2)::after { content: "↙"; top: auto; right: 0; bottom: 0; transform: translate(52%, 52%); }
}

@media (max-width: 640px) {
  .concept-shell { padding-top: 4.2rem; padding-bottom: 5rem; }
  .concept-hero { padding-bottom: 4rem; }
  .concept-hero h1 { font-size: clamp(3.7rem, 22vw, 6.8rem); }
  .concept-section__head,
  .concept-term,
  .concept-callout,
  .concept-footer { grid-template-columns: 1fr; }
  .concept-term .concept-status { margin-top: 0; }
  .concept-side nav { grid-template-columns: 1fr; }
  .concept-side a:nth-child(odd) { border-right: 0; }
  .concept-index-grid,
  .concept-open-list,
  .concept-split { grid-template-columns: 1fr; }
  .concept-index-card,
  .concept-index-card:nth-child(n) { min-height: 18rem; border-left: 1px solid var(--hair); }
  .concept-open-list article:nth-child(n) { padding: 1.5rem 0 2rem; border-left: 0; }
  .concept-split > section + section { border-left: 0; border-top: 1px solid var(--hair); }
  .concept-tree__node { grid-template-columns: 4.4rem minmax(0, 1fr); }
  .concept-tree__node span { grid-column: 2; }
  .dimension-crossing { grid-template-columns: 1fr; }
  .dimension-crossing::before { left: 1rem; }
  .dimension-crossing div { padding-left: 2.3rem; }
  .dimension-crossing div + div { border-left: 0; border-top: 1px solid var(--hair); }
  .concept-flow { grid-template-columns: 1fr; }
  .concept-step + .concept-step { border-left: 0; border-top: 1px solid var(--hair); }
  .concept-step:not(:last-child)::after { content: "↓"; top: auto; right: 50%; bottom: 0; transform: translate(50%, 55%); }
}

@media (prefers-reduced-motion: reduce) {
  .concept-page,
  .concept-side a,
  .concept-index-card,
  .concept-filter button { transition-duration: .01ms !important; }
}

@media (prefers-reduced-transparency: reduce) {
  .concept-index-card:hover,
  .concept-index-card:focus-visible { background: var(--void2); }
}

@media (prefers-contrast: more) {
  .concept-page::before { display: none; }
  .concept-index-card,
  .concept-term,
  .concept-step { border-color: var(--ink); }
}