@font-face {
  font-family: "Noto Sans SC";
  src: url("assets/fonts/NotoSansSC-400.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Noto Sans SC";
  src: url("assets/fonts/NotoSansSC-700.woff2") format("woff2");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Noto Sans SC";
  src: url("assets/fonts/NotoSansSC-900.woff2") format("woff2");
  font-weight: 900;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "IBM Plex Mono";
  src: url("assets/fonts/IBMPlexMono-500.woff2") format("woff2");
  font-weight: 500;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "IBM Plex Mono";
  src: url("assets/fonts/IBMPlexMono-700.woff2") format("woff2");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

:root {
  --paper: #fffdf5;
  --ink: #000000;
  --muted: #2d2d2d;
  --subtle: #636b7d;
  --white: #ffffff;
  --blue: #74b9ff;
  --yellow: #ffd23f;
  --green: #88d498;
  --red: #ff6b6b;
  --lavender: #f5f0fc;
  --panel: #f4f6fa;
  --line-soft: #c7ccd9;
  --border: 3px solid var(--ink);
  --shadow: 6px 6px 0 var(--ink);
  --max: 1248px;
  --sans: "Noto Sans SC", "Microsoft YaHei", "PingFang SC", sans-serif;
  --mono: "IBM Plex Mono", Consolas, monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--sans);
  text-rendering: optimizeLegibility;
}

button,
a { font: inherit; }

a { color: inherit; }

button { color: inherit; }

:focus-visible {
  outline: 4px solid var(--blue);
  outline-offset: 4px;
}

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 200;
  padding: 10px 14px;
  transform: translateY(-150%);
  background: var(--ink);
  color: var(--white);
  font-weight: 700;
}

.skip-link:focus { transform: translateY(0); }

.site-header {
  position: sticky;
  top: 16px;
  z-index: 50;
  width: min(calc(100% - 40px), var(--max));
  margin: 48px auto 0;
  transition: transform .2s ease;
}

.site-header.is-scrolled { transform: translateY(-6px); }

.nav-shell {
  height: 62px;
  min-height: 62px;
  display: flex;
  align-items: center;
  gap: 22px;
  padding: 5px;
  border: var(--border);
  border-radius: 999px;
  background: var(--white);
  box-shadow: var(--shadow);
}

.nav-brand {
  display: inline-grid;
  place-items: center;
  width: 76px;
  height: 46px;
  border: var(--border);
  border-radius: 999px;
  background: var(--blue);
  font: 500 14px/22px var(--sans);
  text-decoration: none;
}

.nav-links {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: space-evenly;
  gap: 10px;
  margin-left: 72px;
}

.nav-links a {
  padding: 12px 24px;
  border: 2px solid transparent;
  font-size: 14px;
  font-weight: 500;
  line-height: 22px;
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a.active { border-color: var(--ink); background: var(--white); }

.nav-toggle {
  display: none;
  margin-left: auto;
  padding: 8px 13px;
  border: 2px solid var(--ink);
  background: var(--white);
  font: 500 14px/22px var(--sans);
}

.case-page {
  width: 100%;
  padding: 86px 20px 96px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 120px;
  overflow: hidden;
}

.case-section { width: min(100%, var(--max)); }

.case-section[id] { scroll-margin-top: 112px; }

.hero-section {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.eyebrow,
.card-kicker {
  margin: 0;
  font-family: var(--mono);
  font-weight: 700;
  letter-spacing: .3px;
  text-transform: uppercase;
}

.eyebrow { font-size: 14px; line-height: 18px; }

.hero-section h1 {
  max-width: 1120px;
  margin: 0;
  font-size: clamp(54px, 6.1vw, 82px);
  font-weight: 900;
  line-height: 1.16;
  letter-spacing: -2.6px;
}

.hero-section h1 span { display: block; }

.hero-lead {
  max-width: 960px;
  margin: 0;
  color: var(--muted);
  font-size: 20px;
  line-height: 34px;
}

.tag-row { display: flex; flex-wrap: wrap; gap: 12px; }

.tag {
  padding: 8px 14px;
  border: 2px solid var(--ink);
  border-radius: 20px;
  box-shadow: 2px 2px 0 var(--ink);
  font-size: 13px;
  font-weight: 700;
  line-height: 20px;
}

.bg-blue { background: var(--blue); }
.bg-yellow { background: var(--yellow); }
.bg-green { background: var(--green); }
.bg-red { background: var(--red); }

.neo-panel {
  border: var(--border);
  background: var(--white);
  box-shadow: 8px 8px 0 var(--ink);
}

.prototype-shell {
  margin-top: 18px;
  padding: 16px;
  background: var(--panel);
}

.prototype-bar {
  min-height: 56px;
  padding: 8px 2px 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.prototype-bar > div:first-child {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 13px;
}

.prototype-bar > div:first-child > span:last-child { color: var(--subtle); }

.status-dot {
  width: 12px;
  height: 12px;
  border: 2px solid var(--ink);
  border-radius: 50%;
  background: var(--green);
}

.prototype-actions { display: flex; gap: 10px; }

.prototype-actions button {
  min-height: 36px;
  padding: 6px 12px;
  border: 2px solid var(--ink);
  background: var(--white);
  box-shadow: 3px 3px 0 var(--ink);
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
}

.prototype-actions button:last-child { background: var(--blue); }

.prototype-desktop {
  width: 100%;
  height: 780px;
  overflow: hidden;
  border: var(--border);
  background: #f1f1ef;
}

.prototype-desktop iframe {
  width: 100%;
  height: 100%;
  display: block;
  border: 0;
}

.prototype-shell:fullscreen {
  width: 100vw;
  height: 100vh;
  margin: 0;
  padding: 12px;
  border: 0;
  box-shadow: none;
}

.prototype-shell:fullscreen .prototype-desktop { height: calc(100vh - 82px); }

.prototype-mobile { display: none; }

.section-heading {
  max-width: 1120px;
  margin-bottom: 44px;
}

.section-heading h2,
.closing-section h2 {
  margin: 14px 0 0;
  font-size: clamp(38px, 4.2vw, 56px);
  font-weight: 900;
  line-height: 1.22;
  letter-spacing: -1.4px;
}

.info-grid {
  display: grid;
  gap: 24px;
}

.four-columns { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.three-columns { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.info-card {
  min-height: 244px;
  padding: 28px;
  border: var(--border);
  box-shadow: 5px 5px 0 var(--ink);
}

.card-kicker { font-size: 12px; line-height: 17px; }

.info-card h3 {
  margin: 18px 0 14px;
  font-size: 25px;
  font-weight: 900;
  line-height: 34px;
}

.info-card p:last-child {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 25px;
}

.research-path {
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
  list-style: none;
}

.research-path li {
  min-height: 214px;
  padding: 28px;
  display: grid;
  grid-template-columns: 62px 1fr;
  gap: 22px;
  border: var(--border);
  background: var(--white);
  box-shadow: var(--shadow);
}

.research-path li:nth-child(1) { background: #ebf5ff; }
.research-path li:nth-child(2) { background: #fff7d6; }
.research-path li:nth-child(3) { background: #edfaf0; }
.research-path li:nth-child(4) { background: #fff0f0; }

.research-path li > span {
  width: 62px;
  height: 62px;
  display: grid;
  place-items: center;
  border: 2px solid var(--ink);
  background: var(--white);
  font: 700 18px/1 var(--mono);
}

.research-path h3 {
  margin: 0 0 14px;
  font-size: 24px;
  line-height: 33px;
}

.research-path p {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 26px;
}

.statement-card {
  margin: 0 0 32px;
  padding: 34px 40px;
  border: var(--border);
  background: var(--blue);
  box-shadow: 8px 8px 0 var(--ink);
  font-size: clamp(28px, 3.2vw, 42px);
  font-weight: 900;
  line-height: 1.4;
}

.judgment-grid .info-card { min-height: 228px; }

.capability-chain {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  border-top: var(--border);
  border-left: var(--border);
  box-shadow: 8px 8px 0 var(--ink);
}

.capability-card {
  min-height: 236px;
  padding: 26px;
  border-right: var(--border);
  border-bottom: var(--border);
}

.tone-blue { background: #ebf5ff; }
.tone-yellow { background: #fff7d6; }
.tone-green { background: #edfaf0; }
.tone-red { background: #fff0f0; }

.capability-card b {
  font: 700 16px/22px var(--mono);
}

.capability-card h3 {
  margin: 30px 0 14px;
  font-size: 25px;
  font-weight: 900;
  line-height: 34px;
}

.capability-card p {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 25px;
}

.flow-board {
  padding: 28px;
  display: grid;
  grid-template-columns: 1fr 34px 1fr 34px 1fr 34px 1fr;
  align-items: stretch;
  border: var(--border);
  background: var(--ink);
  box-shadow: 8px 8px 0 var(--blue);
}

.flow-board article {
  min-height: 240px;
  padding: 26px;
  border: 2px solid var(--white);
  background: var(--white);
}

.flow-board article:nth-of-type(1) { background: var(--blue); }
.flow-board article:nth-of-type(2) { background: var(--yellow); }
.flow-board article:nth-of-type(3) { background: var(--green); }
.flow-board article:nth-of-type(4) { background: var(--red); }

.flow-board span { font: 700 12px/17px var(--mono); }

.flow-board h3 {
  margin: 28px 0 14px;
  font-size: 24px;
  font-weight: 900;
  line-height: 33px;
}

.flow-board p { margin: 0; font-size: 14px; line-height: 24px; }

.flow-board i {
  display: grid;
  place-items: center;
  color: var(--white);
  font: normal 700 24px/1 var(--mono);
}

.result-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 28px;
}

.result-card {
  min-height: 390px;
  padding: 34px;
  border: var(--border);
  box-shadow: var(--shadow);
}

.result-card.completed { background: var(--green); }
.result-card.pending { background: var(--yellow); }

.result-card h3 {
  margin: 20px 0 22px;
  font-size: 31px;
  font-weight: 900;
  line-height: 42px;
}

.result-card ul,
.next-step-panel ol {
  margin: 0;
  padding-left: 23px;
}

.result-card li,
.next-step-panel li {
  margin-bottom: 12px;
  font-size: 16px;
  line-height: 27px;
}

.next-step-panel {
  margin-top: 28px;
  padding: 32px 34px;
  display: grid;
  grid-template-columns: minmax(260px, .7fr) 1.3fr;
  gap: 36px;
  border: var(--border);
  background: var(--white);
  box-shadow: 8px 8px 0 var(--blue);
}

.next-step-panel h3 {
  margin: 16px 0 0;
  font-size: 30px;
  line-height: 40px;
}

.closing-section {
  min-height: 240px;
  padding: 42px 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 36px;
  border: var(--border);
  background: var(--blue);
  box-shadow: 8px 8px 0 var(--ink);
}

.case-links { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 16px; }

.case-links a {
  padding: 13px 18px;
  border: 2px solid var(--ink);
  background: var(--white);
  box-shadow: 4px 4px 0 var(--ink);
  text-decoration: none;
  font: 700 13px/18px var(--mono);
}

.case-links a:first-child { background: var(--yellow); }

.site-footer {
  width: min(calc(100% - 40px), var(--max));
  min-height: 92px;
  margin: 0 auto 32px;
  padding: 22px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: var(--border);
  font: 500 12px/18px var(--mono);
}

@media (max-width: 1199px) {
  .prototype-desktop { height: min(66vw, 740px); }
  .four-columns { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .capability-chain { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .flow-board { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
  .flow-board i { display: none; }
}

@media (max-width: 820px) {
  .site-header { width: calc(100% - 28px); top: 10px; margin-top: 18px; }
  .nav-shell { border-radius: 24px; }
  .nav-toggle { display: inline-flex; }
  .nav-links {
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    margin-left: 0;
    padding: 12px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    border: var(--border);
    background: var(--white);
    box-shadow: var(--shadow);
  }
  .nav-links.open { display: flex; }
  .nav-links a { justify-content: flex-start; }

  .case-page { padding: 56px 18px 72px; gap: 88px; }
  .hero-section { gap: 22px; }
  .hero-section h1 { font-size: clamp(43px, 12.4vw, 62px); line-height: 1.2; letter-spacing: -1.4px; }
  .hero-lead { font-size: 16px; line-height: 28px; }
  .tag { padding: 7px 11px; font-size: 12px; }

  .prototype-shell { margin-top: 8px; padding: 10px; box-shadow: 5px 5px 0 var(--ink); }
  .prototype-bar { align-items: flex-start; }
  .prototype-bar > div:first-child { flex-wrap: wrap; }
  .prototype-bar > div:first-child > span:last-child { flex-basis: 100%; margin-left: 22px; }
  .prototype-actions { display: none; }
  .prototype-desktop { display: none; }
  .prototype-mobile { display: block; }

  .mobile-product-head {
    min-height: 76px;
    padding: 12px;
    display: grid;
    grid-template-columns: 42px 1fr auto;
    align-items: center;
    gap: 10px;
    border: var(--border);
    background: var(--white);
    box-shadow: 4px 4px 0 var(--ink);
  }
  .mobile-mark { width: 42px; height: 42px; display: grid; place-items: center; border: 2px solid var(--ink); background: var(--blue); font-weight: 900; }
  .mobile-product-head div { display: flex; flex-direction: column; gap: 2px; }
  .mobile-product-head strong { font-size: 14px; line-height: 20px; }
  .mobile-product-head div span { color: var(--subtle); font-size: 11px; line-height: 16px; }
  .mobile-product-head b { font: 700 11px/16px var(--mono); }
  .mobile-step-list { margin-top: 14px; display: grid; grid-template-columns: repeat(4, 1fr); gap: 7px; }
  .mobile-step-list button { min-height: 42px; padding: 4px; border: 2px solid var(--ink); background: var(--white); font-size: 10px; font-weight: 700; cursor: pointer; }
  .mobile-step-list button[aria-selected="true"] { background: var(--yellow); box-shadow: 3px 3px 0 var(--ink); }
  .mobile-step-panel { min-height: 370px; margin-top: 14px; padding: 22px; border: var(--border); background: var(--white); box-shadow: 5px 5px 0 var(--ink); }
  .mobile-step-panel .mobile-step-number { font: 700 14px/20px var(--mono); }
  .mobile-step-panel h3 { margin: 26px 0 14px; font-size: 29px; line-height: 39px; }
  .mobile-step-panel p { margin: 0 0 22px; color: var(--muted); font-size: 15px; line-height: 26px; }
  .mobile-step-panel ul { margin: 0; padding-left: 20px; }
  .mobile-step-panel li { margin-bottom: 9px; font-size: 14px; line-height: 24px; }
  .mobile-prototype-actions { margin-top: 14px; display: grid; grid-template-columns: 1fr 1fr; gap: 9px; }
  .mobile-prototype-actions button,
  .mobile-prototype-actions a { min-height: 44px; padding: 9px 10px; display: grid; place-items: center; border: 2px solid var(--ink); background: var(--white); box-shadow: 3px 3px 0 var(--ink); text-decoration: none; font-size: 12px; font-weight: 700; cursor: pointer; }
  .mobile-prototype-actions a { grid-column: 1 / -1; background: var(--blue); }

  .section-heading { margin-bottom: 30px; }
  .section-heading h2,
  .closing-section h2 { font-size: clamp(33px, 9.2vw, 43px); line-height: 1.3; letter-spacing: -.7px; }
  .four-columns,
  .three-columns,
  .research-path,
  .capability-chain,
  .result-grid,
  .next-step-panel,
  .flow-board { grid-template-columns: 1fr; }
  .info-card { min-height: 210px; padding: 26px; }
  .research-path li { min-height: 0; padding: 24px; grid-template-columns: 48px 1fr; gap: 16px; }
  .research-path li > span { width: 48px; height: 48px; font-size: 14px; }
  .research-path h3 { font-size: 21px; line-height: 30px; }
  .statement-card { padding: 28px; font-size: 26px; line-height: 1.5; box-shadow: 5px 5px 0 var(--ink); }
  .capability-chain { box-shadow: 5px 5px 0 var(--ink); }
  .capability-card { min-height: 210px; }
  .flow-board { padding: 16px; }
  .flow-board article { min-height: 210px; }
  .result-card { min-height: 0; padding: 28px; }
  .result-card h3 { font-size: 27px; line-height: 37px; }
  .next-step-panel { padding: 28px; gap: 22px; }
  .closing-section { min-height: 0; padding: 34px 28px; flex-direction: column; align-items: flex-start; }
  .case-links { justify-content: flex-start; }
  .site-footer { width: calc(100% - 36px); flex-direction: column; align-items: flex-start; gap: 6px; }
}

@media (max-width: 430px) {
  .case-page { padding-inline: 14px; }
  .hero-section h1 { font-size: 42px; }
  .prototype-shell { padding: 8px; }
  .mobile-product-head { grid-template-columns: 38px 1fr; }
  .mobile-mark { width: 38px; height: 38px; }
  .mobile-product-head b { grid-column: 2; }
  .mobile-step-list { grid-template-columns: repeat(2, 1fr); }
  .mobile-step-panel { min-height: 410px; padding: 20px; }
  .research-path li { grid-template-columns: 1fr; }
  .case-links { flex-direction: column; width: 100%; }
  .case-links a { width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}