:root {
  --paper: #fff;
  --ink: #0b0e0d;
  --muted: #707670;
  --line: #dfe2df;
  --soft: #f4f6f5;
  --green: #087a59;
  --green-soft: #ebf5f1;
  --red: #b4473a;
  --serif: "Songti SC", "STSong", "Noto Serif CJK SC", Georgia, serif;
  --sans: Inter, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
}

* { box-sizing: border-box; }
html { max-width: 100%; overflow-x: hidden; scroll-behavior: smooth; }
body { max-width: 100%; margin: 0; overflow-x: hidden; color: var(--ink); background: var(--paper); font-family: var(--sans); line-height: 1.62; }
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
button { color: inherit; font: inherit; }
svg { fill: none; stroke: currentColor; stroke-linecap: round; stroke-linejoin: round; }

.case-header { position: sticky; top: 0; z-index: 40; display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; min-height: 64px; padding: 0 42px; background: rgba(255,255,255,.94); border-bottom: 1px solid var(--line); backdrop-filter: blur(16px); }
.case-brand { display: flex; align-items: center; gap: 16px; font-size: 13px; letter-spacing: .05em; }
.case-brand span { width: 74px; height: 1px; background: var(--ink); }
.case-header nav { display: flex; gap: 32px; color: var(--muted); font-size: 13px; }
.case-header nav a { padding: 21px 0 18px; border-bottom: 2px solid transparent; }
.case-header nav a:hover { color: var(--green); border-color: var(--green); }
.back-link { display: flex; justify-content: flex-end; align-items: center; gap: 9px; font-size: 13px; }
.back-link svg { width: 17px; stroke-width: 1.7; }

.case-hero { display: grid; grid-template-columns: 132px minmax(540px,.92fr) minmax(560px,1.08fr); min-height: calc(100svh - 64px); border-bottom: 1px solid var(--line); }
.index-rail { padding: 62px 28px; border-right: 1px solid var(--line); }
.index-rail span, .section-index p { color: var(--muted); font-size: 9px; letter-spacing: .17em; }
.index-rail strong { display: block; margin-top: 12px; font-size: 26px; font-weight: 500; }
.index-rail i, .section-index::after { display: block; width: 22px; height: 1px; margin: 18px 0; content: ""; background: var(--ink); }
.index-rail small { color: var(--muted); font-size: 9px; letter-spacing: .13em; line-height: 1.7; }
.hero-copy { min-width: 0; align-self: center; padding: 70px 46px 70px 5vw; }
.project-name-en { margin: 0 0 22px; color: var(--green); font-size: 10px; font-weight: 600; letter-spacing: .18em; }
.hero-copy h1 { margin: 0; font-size: clamp(74px,8.2vw,132px); letter-spacing: 0; line-height: .92; }
.hero-statement { margin: 34px 0 0; font-family: var(--serif); font-size: clamp(34px,3.4vw,52px); font-weight: 700; line-height: 1.25; }
.hero-statement span { display: block; white-space: nowrap; }
.hero-statement span:last-child { color: var(--green); }
.hero-description { max-width: 590px; margin: 26px 0 34px; color: #414641; font-size: 16px; }
.project-facts { display: grid; gap: 10px; margin: 0; padding-top: 24px; border-top: 1px solid var(--line); font-size: 12px; }
.project-facts div { display: grid; grid-template-columns: 72px 1fr; gap: 18px; }
.project-facts dt { color: var(--muted); }
.project-facts dd { min-width: 0; margin: 0; }

.research-visual { position: relative; min-width: 0; overflow: hidden; background: #f8f9f8; border-left: 1px solid var(--line); }
.visual-head { position: absolute; z-index: 3; top: 42px; right: 40px; left: 40px; display: flex; justify-content: space-between; padding-bottom: 14px; border-bottom: 1px solid var(--line); font-size: 9px; letter-spacing: .16em; }
.visual-head strong { color: var(--green); font-size: 9px; }
.company-signal { position: absolute; z-index: 4; top: 50%; left: 50%; width: 270px; min-height: 205px; padding: 34px; background: var(--ink); color: #fff; transform: translate(-50%,-50%); }
.company-signal span { color: #aeb4b0; font-size: 9px; letter-spacing: .14em; }
.company-signal strong { display: block; margin-top: 28px; font-family: var(--serif); font-size: 25px; line-height: 1.4; }
.company-signal small { position: absolute; left: 34px; bottom: 22px; color: #8f9691; font-size: 8px; letter-spacing: .12em; }
.research-visual ol { position: absolute; z-index: 3; inset: 100px 38px 46px; margin: 0; padding: 0; list-style: none; }
.research-visual li { position: absolute; display: grid; grid-template-columns: 28px 1fr auto; align-items: center; width: 210px; min-height: 58px; padding: 0 14px; background: rgba(255,255,255,.94); border: 1px solid var(--line); }
.research-visual li:nth-child(1) { top: 4%; left: 0; }
.research-visual li:nth-child(2) { top: 3%; right: 0; }
.research-visual li:nth-child(3) { top: 42%; left: 0; }
.research-visual li:nth-child(4) { top: 42%; right: 0; }
.research-visual li:nth-child(5) { bottom: 2%; left: 1%; }
.research-visual li:nth-child(6) { right: 1%; bottom: 2%; }
.research-visual li > span { color: var(--muted); font-size: 8px; }
.research-visual li strong { font-family: var(--serif); font-size: 16px; }
.research-visual li small { color: var(--green); font-size: 7px; }
.ask-ai { position: absolute; z-index: 5; top: 20%; left: 50%; width: 154px; padding: 12px 14px; background: var(--green-soft); border: 1px solid #bbd9cd; transform: translateX(-50%); }
.ask-ai span { color: var(--green); font-size: 8px; letter-spacing: .14em; }
.ask-ai p { margin: 4px 0 0; font-size: 9px; }
.ask-ai i { position: absolute; right: 12px; bottom: -5px; width: 9px; height: 9px; background: var(--green-soft); border-right: 1px solid #bbd9cd; border-bottom: 1px solid #bbd9cd; transform: rotate(45deg); }
.research-visual > svg { position: absolute; inset: 7%; width: 86%; height: 86%; color: #979e99; }
.research-visual > svg path { stroke-width: 1; }
.research-visual > svg path:first-child { color: var(--green); }
.research-visual circle { fill: var(--green); stroke: none; }

.ruled-section { display: grid; grid-template-columns: 132px repeat(11,minmax(0,1fr)); border-bottom: 1px solid var(--line); }
.section-index { grid-column: 1; grid-row: 1 / span 4; padding: 72px 28px; border-right: 1px solid var(--line); }
.section-index span { font-size: 18px; }
.section-index p { margin: 10px 0 0; line-height: 1.55; }
.problem-heading, .judgment-copy, .research-heading, .system-heading, .status-heading { grid-column: 2 / 13; padding: 86px 5vw 54px; }
.problem-heading > p, .judgment-copy > p, .research-heading > p, .system-heading > p, .prototype-copy > p, .boundary-heading > p, .status-heading > p { margin: 0 0 14px; color: var(--muted); font-size: 11px; letter-spacing: .08em; }
.problem-heading h2, .judgment-copy h2, .research-heading h2, .system-heading h2, .prototype-copy h2, .boundary-heading h2, .status-heading h2 { margin: 0; font-family: var(--serif); font-size: clamp(38px,4.6vw,68px); line-height: 1.22; }

.problem-grid { grid-column: 2 / 13; display: grid; grid-template-columns: repeat(3,1fr); border-top: 1px solid var(--line); }
.problem-grid article { min-height: 270px; padding: 34px 3vw; border-right: 1px solid var(--line); }
.problem-grid article:last-child { border-right: 0; }
.problem-grid span, .judgment-split span, .system-layers span, .boundary-map span, .status-columns span { color: var(--muted); font-size: 10px; letter-spacing: .14em; }
.problem-grid strong { display: block; margin: 72px 0 9px; font-family: var(--serif); font-size: 25px; }
.problem-grid p { margin: 0; color: var(--muted); }

.judgment-copy { grid-column: 2 / 8; padding-right: 4vw; }
.judgment-split { grid-column: 8 / 13; display: grid; grid-template-rows: 1fr 42px 1fr; border-left: 1px solid var(--line); }
.judgment-split article { padding: 40px 3vw; }
.judgment-split strong { display: block; margin: 48px 0 8px; font-family: var(--serif); font-size: 27px; }
.judgment-split p { margin: 0; color: var(--muted); }
.judgment-split > i { width: 1px; height: 42px; margin-left: 3vw; background: var(--ink); }
.judgment-split article:last-child { background: var(--green-soft); border-top: 3px solid var(--green); }
.judgment-split article:last-child span { color: var(--green); }

.research-interface { grid-column: 2 / 13; display: grid; grid-template-columns: minmax(330px,.38fr) minmax(0,.62fr); border-top: 1px solid var(--line); }
.research-tabs { display: grid; border-right: 1px solid var(--line); }
.research-tab { display: grid; grid-template-columns: 48px 1fr; align-items: center; min-height: 68px; padding: 0 30px; background: #fff; border: 0; border-bottom: 1px solid var(--line); cursor: pointer; text-align: left; }
.research-tab span { color: var(--muted); font-size: 9px; }
.research-tab:hover { background: var(--soft); }
.research-tab.active { color: #fff; background: var(--ink); }
.research-tab.active span { color: #aeb4b0; }
.research-tab:focus { outline: none; }
.research-tab:focus-visible { box-shadow: inset 0 0 0 1px #b5bbb7; }
.research-detail { display: grid; grid-template-columns: .72fr 1.28fr; gap: 44px; min-height: 430px; padding: 58px; }
.research-detail > span { grid-column: 1 / -1; color: var(--green); font-size: 10px; letter-spacing: .16em; }
.research-detail h3 { margin: 0; font-family: var(--serif); font-size: 35px; line-height: 1.35; }
.research-detail > p { margin: 0; color: #424742; font-size: 16px; }
.research-detail dl { grid-column: 1 / -1; display: grid; grid-template-columns: repeat(3,1fr); margin: 24px 0 0; border-top: 1px solid var(--line); }
.research-detail dl div { padding: 18px 22px 0 0; }
.research-detail dt { color: var(--muted); font-size: 10px; }
.research-detail dd { margin: 6px 0 0; font-size: 13px; }

.system-layers { grid-column: 2 / 13; display: grid; grid-template-columns: repeat(5,1fr); border-top: 1px solid var(--line); }
.system-layers article { min-height: 260px; padding: 34px 2vw; border-right: 1px solid var(--line); }
.system-layers article:last-child { border-right: 0; }
.system-layers strong { display: block; margin: 72px 0 8px; font-family: var(--serif); font-size: 23px; }
.system-layers p { margin: 0; color: var(--muted); font-size: 13px; }

.prototype-copy { grid-column: 2 / 6; padding: 82px 4vw; }
.prototype-copy h2 { font-size: clamp(36px,4vw,58px); }
.prototype-copy ul { margin: 42px 0 0; padding: 0; list-style: none; border-top: 1px solid var(--line); }
.prototype-copy li { padding: 12px 0; color: var(--muted); border-bottom: 1px solid var(--line); }
.prototype figure { grid-column: 6 / 13; margin: 0; padding: 74px 4vw; background: var(--soft); border-left: 1px solid var(--line); }
.prototype figure img { border: 1px solid #cfd4d1; box-shadow: 0 18px 38px rgba(24,30,27,.09); }
.prototype figcaption { margin-top: 12px; color: var(--muted); font-size: 9px; letter-spacing: .13em; }

.boundary-heading { grid-column: 2 / 8; padding: 86px 5vw; }
.boundary-map { grid-column: 8 / 13; display: grid; grid-template-columns: 1fr 1fr; border-left: 1px solid var(--line); }
.boundary-map > div { padding: 76px 32px; }
.boundary-map > div + div { border-left: 1px solid var(--line); }
.boundary-map p, .status-columns p { margin: 16px 0 0; padding-bottom: 9px; border-bottom: 1px solid var(--line); }
.boundary-map .blocked { background: #faf1ef; }
.boundary-map .blocked span { color: var(--red); }

.status-heading { grid-column: 2 / 8; }
.status-columns { grid-column: 8 / 13; display: grid; grid-template-columns: 1fr 1fr; border-left: 1px solid var(--line); }
.status-columns article { padding: 72px 32px; }
.status-columns article + article { border-left: 1px solid var(--line); }
.status-columns p { color: #414641; font-size: 13px; }

.case-cta { display: grid; place-items: center; min-height: 620px; padding: 100px 28px; text-align: center; }
.case-cta > p { margin: 0; color: var(--green); font-size: 10px; font-weight: 600; letter-spacing: .22em; }
.case-cta h2 { margin: 18px 0 42px; font-family: var(--serif); font-size: clamp(48px,7vw,96px); line-height: 1.18; }
.primary-action { display: inline-flex; align-items: center; justify-content: center; gap: 38px; min-width: 224px; min-height: 58px; padding: 0 24px; color: #fff; background: var(--ink); }
.primary-action svg { width: 18px; stroke-width: 1.7; }
.case-footer { display: grid; grid-template-columns: 1fr auto 1fr; gap: 24px; padding: 26px 42px; border-top: 1px solid var(--line); font-size: 11px; }
.case-footer span { color: var(--muted); letter-spacing: .1em; }
.case-footer a { text-align: right; }
.reveal { opacity: 0; transform: translateY(20px); transition: opacity .65s ease, transform .65s ease; }
.reveal.visible { opacity: 1; transform: none; }

@media (max-width: 1180px) {
  .case-header { grid-template-columns: 1fr auto; padding: 0 24px; }
  .case-header nav { display: none; }
  .case-hero { grid-template-columns: 88px 1fr; }
  .index-rail { grid-row: 1 / span 2; padding: 48px 18px; }
  .hero-copy { padding: 64px 6vw; }
  .research-visual { grid-column: 2; min-height: 720px; border-top: 1px solid var(--line); border-left: 0; }
  .ruled-section { grid-template-columns: 88px repeat(11,minmax(0,1fr)); }
  .section-index { padding: 58px 18px; }
  .judgment-copy, .boundary-heading, .status-heading { grid-column: 2 / 13; }
  .judgment-split, .boundary-map, .status-columns { grid-column: 2 / 13; border-top: 1px solid var(--line); border-left: 0; }
  .system-layers { grid-template-columns: repeat(3,1fr); }
  .system-layers article { border-bottom: 1px solid var(--line); }
}

@media (max-width: 720px) {
  .case-header { min-height: 58px; padding: 0 20px; }
  .case-brand span { width: 34px; }
  .back-link { font-size: 0; }
  .case-hero, .ruled-section { display: block; }
  .index-rail, .section-index { display: none; }
  .hero-copy { padding: 58px 20px 64px; }
  .hero-copy h1 { font-size: 66px; }
  .hero-statement { font-size: 35px; }
  .hero-statement span { white-space: normal; }
  .hero-description { font-size: 15px; }
  .hero-description, .project-facts dd { overflow-wrap: anywhere; }
  .project-facts div { grid-template-columns: 70px 1fr; }
  .research-visual { min-height: 720px; }
  .visual-head { right: 20px; left: 20px; }
  .company-signal { width: 210px; min-height: 180px; padding: 26px; }
  .company-signal strong { font-size: 21px; }
  .company-signal small { left: 26px; }
  .research-visual ol { inset: 100px 14px 36px; }
  .research-visual li { width: 160px; grid-template-columns: 24px 1fr; padding: 0 10px; }
  .research-visual li small { display: none; }
  .ask-ai { top: 22%; }
  .problem-heading, .judgment-copy, .research-heading, .system-heading, .prototype-copy, .boundary-heading, .status-heading { padding: 72px 20px 40px; }
  .problem-heading h2, .judgment-copy h2, .research-heading h2, .system-heading h2, .prototype-copy h2, .boundary-heading h2, .status-heading h2 { font-size: 36px; }
  .problem-grid, .judgment-split, .system-layers, .boundary-map, .status-columns { display: block; }
  .problem-grid article, .system-layers article { min-height: 230px; padding: 30px 20px; border-right: 0; border-bottom: 1px solid var(--line); }
  .problem-grid strong, .system-layers strong { margin-top: 52px; }
  .judgment-split article { padding: 42px 20px; }
  .judgment-split > i { margin-left: 20px; }
  .research-interface { display: block; }
  .research-tabs { grid-template-columns: repeat(6,minmax(138px,1fr)); overflow-x: auto; border-right: 0; }
  .research-tab { display: block; min-height: 78px; padding: 12px; white-space: nowrap; }
  .research-tab span { display: block; margin-bottom: 4px; }
  .research-detail { display: block; min-height: 560px; padding: 38px 20px; }
  .research-detail h3 { margin-top: 22px; font-size: 31px; }
  .research-detail > p { margin-top: 24px; }
  .research-detail dl { grid-template-columns: 1fr; }
  .research-detail dl div { padding: 14px 0; border-bottom: 1px solid var(--line); }
  .prototype figure { padding: 34px 20px 66px; border-top: 1px solid var(--line); border-left: 0; overflow: hidden; }
  .prototype figure img { width: 900px; max-width: none; transform: translateX(-180px); }
  .boundary-map > div, .status-columns article { padding: 54px 20px; }
  .boundary-map > div + div, .status-columns article + article { border-top: 1px solid var(--line); border-left: 0; }
  .case-cta { min-height: 540px; padding: 80px 20px; }
  .case-cta h2 { font-size: 54px; }
  .case-footer { grid-template-columns: 1fr auto; padding: 24px 20px; }
  .case-footer span { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
}