:root {
  --paper: oklch(94.5% 0.012 100);
  --paper-deep: oklch(89% 0.018 105);
  --ink: oklch(22% 0.035 158);
  --ink-soft: oklch(42% 0.025 158);
  --forest: oklch(29% 0.055 160);
  --forest-deep: oklch(18% 0.035 160);
  --celadon: oklch(76% 0.055 160);
  --red: oklch(55% 0.15 35);
  --line: oklch(28% 0.025 158 / 0.22);
  --serif: "Noto Serif SC", "Songti SC", SimSun, serif;
  --sans: "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(90deg, transparent calc(100% - 1px), oklch(28% 0.025 158 / 0.04) 1px),
    var(--paper);
  background-size: 6.25vw 100%;
  font-family: var(--sans);
  line-height: 1.75;
  font-kerning: normal;
  overflow-x: clip;
}
a { color: inherit; }
h1, h2, h3, p { text-wrap: pretty; }

.skip-link { position: fixed; z-index: 30; top: 10px; left: 10px; padding: 10px 14px; color: var(--paper); background: var(--forest-deep); transform: translateY(-160%); }
.skip-link:focus { transform: translateY(0); }
a:focus-visible, summary:focus-visible { outline: 2px solid var(--red); outline-offset: 4px; }

.site-header {
  min-height: 76px;
  padding: 14px clamp(20px, 4vw, 64px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 11px; font-family: var(--serif); font-weight: 600; text-decoration: none; letter-spacing: 0.06em; }
.brand img { width: 42px; height: 42px; object-fit: cover; border-radius: 50%; }
.header-nav { display: flex; align-items: center; gap: clamp(20px, 3vw, 40px); font-size: 0.75rem; }
.header-nav a { min-height: 44px; display: grid; place-items: center; text-underline-offset: 5px; }

main, footer { width: min(1240px, calc(100% - 40px)); margin-inline: auto; }

.hero { min-height: calc(100vh - 77px); padding-block: clamp(64px, 8vw, 112px); display: grid; grid-template-columns: minmax(0, 0.9fr) minmax(420px, 0.7fr); gap: clamp(48px, 8vw, 120px); align-items: center; }
.eyebrow, .edition, .section-number, .board-head, .board-label, .level-label { margin: 0; font-size: 0.68rem; font-weight: 600; letter-spacing: 0.2em; }
.eyebrow, .section-number { color: var(--red); }
.edition { margin-top: 48px; color: var(--ink-soft); }
h1 { margin: 18px 0 24px; font-family: var(--serif); font-size: clamp(5rem, 10vw, 10rem); line-height: 0.92; font-weight: 600; letter-spacing: -0.07em; }
h1 span { color: var(--forest); font-family: Georgia, "Times New Roman", serif; font-size: 0.88em; letter-spacing: -0.085em; }
.hero-subtitle { margin: 0 0 30px; font-family: var(--serif); font-size: clamp(1.5rem, 2.6vw, 2.35rem); line-height: 1.45; }
.lead { max-width: 42rem; margin: 0; color: var(--ink-soft); font-size: 1rem; line-height: 2; }

.field-board { min-height: 630px; padding: 24px clamp(24px, 3vw, 40px) 32px; position: relative; color: var(--paper); background: var(--forest-deep); overflow: hidden; isolation: isolate; animation: board-in 700ms var(--ease-out) both; }
.field-board::before { content: "F"; position: absolute; z-index: -1; right: -0.07em; top: -0.2em; color: oklch(76% 0.055 160 / 0.09); font-family: Georgia, "Times New Roman", serif; font-size: 29rem; line-height: 1; }
.board-head { padding-bottom: 18px; display: flex; justify-content: space-between; gap: 20px; color: var(--celadon); border-bottom: 1px solid oklch(94.5% 0.012 100 / 0.24); }
.board-axis { width: 46%; height: 130px; margin: 36px 0 0 auto; position: relative; border-left: 1px solid var(--celadon); border-bottom: 1px solid var(--celadon); }
.board-axis::before { content: ""; position: absolute; inset: 24% 0 0 0; border-top: 1px solid oklch(76% 0.055 160 / 0.38); transform: skewY(-26deg); transform-origin: bottom left; }
.board-axis i { width: 6px; height: 6px; position: absolute; background: var(--red); border-radius: 50%; }
.board-axis i:nth-child(1) { left: -3px; bottom: -3px; }
.board-axis i:nth-child(2) { left: 32%; bottom: 24%; }
.board-axis i:nth-child(3) { left: 64%; bottom: 55%; }
.board-axis i:nth-child(4) { right: -3px; top: -3px; }
.board-label { margin-top: 30px; color: var(--celadon); }
.board-title { margin: 12px 0 28px; font-family: var(--serif); font-size: clamp(2rem, 3.2vw, 3.2rem); line-height: 1.36; letter-spacing: -0.04em; }
.board-list { margin: 0; padding: 0; display: grid; grid-template-columns: 1fr 1fr; list-style: none; border-top: 1px solid oklch(94.5% 0.012 100 / 0.24); }
.board-list li { padding: 13px 8px 13px 0; display: grid; grid-template-columns: 32px 1fr; gap: 5px; border-bottom: 1px solid oklch(94.5% 0.012 100 / 0.18); font-size: 0.75rem; }
.board-list li:nth-child(odd) { border-right: 1px solid oklch(94.5% 0.012 100 / 0.18); }
.board-list li:nth-child(even) { padding-left: 14px; }
.board-list span { color: var(--celadon); font-size: 0.62rem; }

.page-index { display: grid; grid-template-columns: repeat(6, 1fr); border-block: 1px solid var(--ink); }
.page-index a { min-height: 88px; padding: 18px; display: flex; flex-direction: column; justify-content: space-between; border-right: 1px solid var(--line); text-decoration: none; font-family: var(--serif); font-size: 0.92rem; transition: color 200ms var(--ease-out), background-color 200ms var(--ease-out); }
.page-index a:last-child { border-right: 0; }
.page-index span { color: var(--red); font-family: var(--sans); font-size: 0.63rem; }

.section { padding-block: clamp(96px, 12vw, 168px); }
.definition { display: grid; grid-template-columns: 116px minmax(0, 1fr); gap: 34px; }
.definition-copy h2, .section-heading h2, .start h2, .future h2 { margin: 0; font-family: var(--serif); font-size: clamp(2.7rem, 5.3vw, 5.25rem); line-height: 1.24; font-weight: 600; letter-spacing: -0.05em; }
.section-lead { max-width: 700px; margin: 28px 0 0; color: var(--ink-soft); font-family: var(--serif); font-size: 1.1rem; line-height: 1.95; }
.definition-grid { grid-column: 2; margin-top: 72px; display: grid; grid-template-columns: repeat(4, 1fr); border-block: 1px solid var(--ink); }
.definition-grid article { min-height: 270px; padding: 26px; border-right: 1px solid var(--line); }
.definition-grid article:first-child { padding-left: 0; }
.definition-grid article:last-child { border-right: 0; }
.definition-grid span { color: var(--red); font-size: 0.7rem; font-weight: 600; letter-spacing: 0.12em; }
.definition-grid p { margin: 74px 0 0; color: var(--ink-soft); font-family: var(--serif); font-size: 1rem; }
.definition-grid .definition-result { padding-inline: 26px; color: var(--paper); background: var(--forest-deep); }
.definition-grid .definition-result p { color: var(--paper); font-size: 1.16rem; }

.value-strip { margin-inline: calc(50% - 50vw); padding: 30px max(20px, calc((100vw - 1240px) / 2)); display: grid; grid-template-columns: 230px 1fr; gap: 34px; align-items: start; color: var(--paper); background: var(--forest); }
.value-strip > p { margin: 0; color: var(--celadon); font-size: 0.7rem; font-weight: 600; letter-spacing: 0.15em; }
.value-strip ul { margin: 0; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; list-style: none; }
.value-strip li { padding: 0 18px 18px 0; border-bottom: 1px solid oklch(94.5% 0.012 100 / 0.24); font-family: var(--serif); }

.section-heading { margin-bottom: clamp(56px, 7vw, 92px); display: grid; grid-template-columns: 116px minmax(0, 1fr); gap: 34px; align-items: start; }
.section-heading > div > p { max-width: 680px; margin: 22px 0 0; color: var(--ink-soft); }
.level-list { margin: 0 0 0 150px; padding: 0; list-style: none; border-top: 1px solid var(--ink); }
.level-list li { min-height: 180px; padding: 28px 0; display: grid; grid-template-columns: 58px minmax(210px, 0.65fr) minmax(280px, 1fr) 140px; gap: 28px; align-items: center; border-bottom: 1px solid var(--line); }
.level-list li > span { align-self: start; color: var(--red); font-size: 0.7rem; }
.level-label { color: var(--ink-soft); }
.level-list h3 { margin: 14px 0 0; font-family: var(--serif); font-size: 1.55rem; }
.level-list li > p { margin: 0; color: var(--ink-soft); font-size: 0.88rem; }
.level-list em { color: var(--forest); font-size: 0.72rem; font-style: normal; text-align: right; }

.fields { border-top: 1px solid var(--ink); }
.field-list { margin-left: 150px; border-top: 1px solid var(--ink); }
.field-list details { border-bottom: 1px solid var(--line); scroll-margin-top: 24px; }
.field-list summary { min-height: 130px; padding: 26px 0; display: grid; grid-template-columns: 48px minmax(210px, 0.6fr) minmax(250px, 1fr) 92px; gap: 24px; align-items: center; cursor: pointer; list-style: none; }
.field-list summary::-webkit-details-marker { display: none; }
.field-list summary > span { align-self: start; color: var(--red); font-size: 0.7rem; }
.field-list summary div p { margin: 0; color: var(--ink-soft); font-size: 0.62rem; font-weight: 600; letter-spacing: 0.16em; }
.field-list h3 { margin: 8px 0 0; font-family: var(--serif); font-size: clamp(1.35rem, 2.1vw, 1.85rem); }
.field-list summary > b { font-size: 0.85rem; font-weight: 400; color: var(--ink-soft); }
.field-list summary em { color: var(--forest); font-size: 0.68rem; font-style: normal; text-align: right; }
.field-list summary em::after { content: " ＋"; color: var(--red); font-size: 1rem; }
.field-list details[open] summary em::after { content: " －"; }
.field-detail { padding: 0 92px 36px 72px; display: grid; grid-template-columns: repeat(3, 1fr); gap: clamp(24px, 4vw, 48px); }
.field-detail p { margin: 0; color: var(--ink-soft); font-size: 0.84rem; }
.field-detail strong { color: var(--ink); font-weight: 600; }

.start { margin-inline: calc(50% - 50vw); padding: clamp(94px, 11vw, 150px) max(20px, calc((100vw - 1240px) / 2)); display: grid; grid-template-columns: minmax(0, 0.8fr) minmax(440px, 1.2fr); gap: clamp(54px, 8vw, 120px); color: var(--paper); background: var(--forest-deep); }
.start .section-number { color: var(--celadon); }
.start h2 { margin-top: 40px; }
.start-intro > p:last-child { max-width: 470px; margin: 28px 0 0; color: var(--celadon); }
.start-steps { margin: 0; padding: 0; list-style: none; border-top: 1px solid oklch(94.5% 0.012 100 / 0.35); }
.start-steps li { padding: 20px 0; display: grid; grid-template-columns: 44px 1fr; gap: 18px; border-bottom: 1px solid oklch(94.5% 0.012 100 / 0.2); }
.start-steps span { color: var(--celadon); font-size: 0.67rem; }
.start-steps h3 { margin: 0; font-family: var(--serif); font-size: 1.12rem; }
.start-steps p { margin: 7px 0 0; color: var(--celadon); font-size: 0.8rem; }
.start-rule { grid-column: 1 / -1; margin: 22px 0 0; padding-top: 26px; color: var(--celadon); border-top: 1px solid oklch(94.5% 0.012 100 / 0.35); font-family: var(--serif); font-size: clamp(1.15rem, 2vw, 1.5rem); text-align: center; letter-spacing: 0.13em; }

.boundary-grid { margin-left: 150px; display: grid; grid-template-columns: 1fr 1fr; border-block: 1px solid var(--ink); }
.boundary-grid article { padding: 34px clamp(30px, 5vw, 72px) 46px; border-right: 1px solid var(--line); }
.boundary-grid article:first-child { padding-left: 0; }
.boundary-grid article:last-child { border-right: 0; }
.boundary-grid p { margin: 0 0 32px; color: var(--red); font-size: 0.7rem; font-weight: 600; letter-spacing: 0.15em; }
.boundary-grid ul { margin: 0; padding: 0; list-style: none; }
.boundary-grid li { padding: 14px 0; border-top: 1px solid var(--line); font-family: var(--serif); font-size: 1.05rem; }

.measure { border-top: 1px solid var(--ink); }
.measure-grid { margin-left: 150px; display: grid; grid-template-columns: repeat(5, 1fr); border-block: 1px solid var(--ink); }
.measure-grid article { min-height: 290px; padding: 26px; border-right: 1px solid var(--line); }
.measure-grid article:first-child { padding-left: 0; }
.measure-grid article:last-child { border-right: 0; }
.measure-grid span { color: var(--red); font-size: 0.68rem; }
.measure-grid h3 { margin: 62px 0 20px; font-family: var(--serif); font-size: 1.4rem; }
.measure-grid p { margin: 0; color: var(--ink-soft); font-size: 0.8rem; }

.future { margin-inline: calc(50% - 50vw); padding: clamp(94px, 11vw, 150px) max(20px, calc((100vw - 1240px) / 2)); color: var(--paper); background: var(--forest); }
.future .section-number { color: var(--celadon); }
.future-heading { display: grid; grid-template-columns: 116px minmax(0, 1fr); gap: 34px; }
.fashion-chain { margin: 86px 0 0; padding: 0; display: grid; grid-template-columns: repeat(9, 1fr); list-style: none; border-block: 1px solid oklch(94.5% 0.012 100 / 0.45); }
.fashion-chain li { min-height: 106px; padding: 20px 8px; display: grid; place-items: center; position: relative; border-right: 1px solid oklch(94.5% 0.012 100 / 0.22); font-family: var(--serif); }
.fashion-chain li:last-child { border-right: 0; }
.fashion-chain li:not(:last-child)::after { content: "→"; position: absolute; z-index: 2; right: -0.65em; color: var(--celadon); }
.future-copy { max-width: 800px; margin: 44px 0 0 auto; color: var(--celadon); font-family: var(--serif); font-size: 1rem; line-height: 2; }

footer { padding-block: 36px max(56px, env(safe-area-inset-bottom)); display: grid; grid-template-columns: 1fr 1fr auto; gap: 24px; color: var(--ink-soft); font-size: 0.75rem; }
footer p { margin: 0; }
footer a { text-underline-offset: 5px; }

@keyframes board-in { from { opacity: 0; transform: translateY(22px); } to { opacity: 1; transform: translateY(0); } }

@media (hover: hover) {
  .page-index a:hover { color: var(--paper); background: var(--forest-deep); }
  .field-list summary:hover h3 { color: var(--forest); }
}

@media (max-width: 960px) {
  body { background-size: 12.5vw 100%; }
  .hero { min-height: auto; grid-template-columns: 1fr; }
  .field-board { min-height: 590px; }
  .page-index { grid-template-columns: repeat(3, 1fr); }
  .page-index a:nth-child(-n + 3) { border-bottom: 1px solid var(--line); }
  .page-index a:nth-child(3) { border-right: 0; }
  .definition, .section-heading, .future-heading { grid-template-columns: 72px minmax(0, 1fr); gap: 22px; }
  .definition-grid { grid-column: 1 / -1; grid-template-columns: 1fr 1fr; }
  .definition-grid article:nth-child(-n + 2) { border-bottom: 1px solid var(--line); }
  .definition-grid article:nth-child(2) { border-right: 0; }
  .definition-grid article:nth-child(3) { padding-left: 0; }
  .value-strip { grid-template-columns: 1fr; }
  .level-list, .field-list, .boundary-grid, .measure-grid { margin-left: 94px; }
  .level-list li { grid-template-columns: 44px minmax(180px, 0.7fr) minmax(0, 1fr); }
  .level-list em { grid-column: 3; text-align: left; }
  .field-list summary { grid-template-columns: 40px minmax(190px, 0.7fr) minmax(0, 1fr); }
  .field-list summary em { grid-column: 3; text-align: left; }
  .field-detail { grid-template-columns: 1fr; gap: 14px; }
  .start { grid-template-columns: 1fr; }
  .measure-grid { grid-template-columns: repeat(3, 1fr); }
  .measure-grid article:nth-child(3) { border-right: 0; }
  .measure-grid article:nth-child(-n + 3) { border-bottom: 1px solid var(--line); }
  .fashion-chain { grid-template-columns: repeat(5, 1fr); }
  .fashion-chain li:nth-child(5) { border-right: 0; }
  .fashion-chain li:nth-child(-n + 5) { border-bottom: 1px solid oklch(94.5% 0.012 100 / 0.22); }
  .fashion-chain li:nth-child(5)::after { display: none; }
}

@media (max-width: 640px) {
  body { background-size: 25vw 100%; }
  .site-header { min-height: 66px; padding-left: max(16px, env(safe-area-inset-left)); padding-right: max(16px, env(safe-area-inset-right)); }
  .brand { min-width: 0; gap: 8px; }
  .brand img { width: 32px; height: 32px; }
  .brand span { font-size: 0.75rem; white-space: nowrap; }
  .header-nav a:not(:last-child) { display: none; }
  .header-nav { font-size: 0.75rem; white-space: nowrap; }
  main, footer { width: min(1240px, calc(100% - 32px - env(safe-area-inset-left) - env(safe-area-inset-right))); }
  .hero { padding-block: 52px 72px; gap: 44px; }
  .edition { margin-top: 34px; }
  h1 { font-size: clamp(4.3rem, 22vw, 6rem); }
  .hero-subtitle { font-size: 1.4rem; }
  .lead { font-size: 0.94rem; }
  .field-board { min-height: 560px; padding: 20px; }
  .field-board::before { font-size: 22rem; }
  .board-head { letter-spacing: 0.11em; }
  .board-axis { height: 102px; }
  .board-title { font-size: 2rem; }
  .board-list { grid-template-columns: 1fr; }
  .board-list li:nth-child(odd) { border-right: 0; }
  .board-list li:nth-child(even) { padding-left: 0; }
  .page-index { grid-template-columns: 1fr 1fr; }
  .page-index a { min-height: 78px; padding: 15px 12px; border-bottom: 1px solid var(--line); }
  .page-index a:nth-child(2n) { border-right: 0; }
  .page-index a:nth-child(3) { border-right: 1px solid var(--line); }
  .page-index a:nth-last-child(-n + 2) { border-bottom: 0; }
  .section { padding-block: 78px; }
  .definition, .section-heading, .future-heading { grid-template-columns: 30px minmax(0, 1fr); gap: 10px; }
  .definition-copy h2, .section-heading h2, .start h2, .future h2 { font-size: clamp(2.1rem, 10.5vw, 3rem); }
  .section-lead, .section-heading > div > p { font-size: 0.9rem; }
  .definition-grid { margin-top: 48px; grid-template-columns: 1fr; }
  .definition-grid article, .definition-grid article:first-child, .definition-grid article:nth-child(3) { min-height: 0; padding: 28px 0; border-right: 0; border-bottom: 1px solid var(--line); }
  .definition-grid article:last-child { padding-inline: 20px; border-bottom: 0; }
  .definition-grid p { margin-top: 28px; }
  .value-strip { padding-left: max(16px, env(safe-area-inset-left)); padding-right: max(16px, env(safe-area-inset-right)); }
  .value-strip ul { grid-template-columns: 1fr 1fr; }
  .value-strip li { font-size: 0.85rem; }
  .section-heading { margin-bottom: 50px; }
  .level-list, .field-list, .boundary-grid, .measure-grid { margin-left: 0; }
  .level-list li { grid-template-columns: 32px minmax(0, 1fr); gap: 10px; }
  .level-list li > p, .level-list em { grid-column: 2; }
  .field-list summary { min-height: 120px; grid-template-columns: 32px minmax(0, 1fr); gap: 10px; }
  .field-list summary > b, .field-list summary em { grid-column: 2; text-align: left; }
  .field-list summary > b { font-size: 0.78rem; }
  .field-detail { padding: 0 0 32px 42px; }
  .start, .future { padding-left: max(16px, env(safe-area-inset-left)); padding-right: max(16px, env(safe-area-inset-right)); }
  .start-rule { font-size: 0.92rem; letter-spacing: 0.05em; }
  .boundary-grid { grid-template-columns: 1fr; }
  .boundary-grid article, .boundary-grid article:first-child { padding: 30px 0; border-right: 0; border-bottom: 1px solid var(--line); }
  .boundary-grid article:last-child { border-bottom: 0; }
  .measure-grid { grid-template-columns: 1fr; }
  .measure-grid article, .measure-grid article:first-child { min-height: 0; padding: 26px 0; border-right: 0; border-bottom: 1px solid var(--line); }
  .measure-grid article:last-child { border-bottom: 0; }
  .measure-grid h3 { margin-top: 26px; }
  .fashion-chain { margin-top: 54px; grid-template-columns: repeat(3, 1fr); }
  .fashion-chain li { min-height: 82px; }
  .fashion-chain li:nth-child(3n) { border-right: 0; }
  .fashion-chain li:nth-child(-n + 6) { border-bottom: 1px solid oklch(94.5% 0.012 100 / 0.22); }
  .fashion-chain li:nth-child(3)::after, .fashion-chain li:nth-child(6)::after { display: none; }
  .fashion-chain li:nth-child(5) { border-right: 1px solid oklch(94.5% 0.012 100 / 0.22); }
  .fashion-chain li:nth-child(5)::after { display: block; }
  .future-copy { font-size: 0.9rem; }
  footer { grid-template-columns: 1fr; gap: 8px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}