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

:root {
  color-scheme: dark;
  --bg: oklch(0.13 0.008 55);
  --bg-raised: oklch(0.155 0.01 52);
  --surface: oklch(0.185 0.012 48);
  --surface-strong: oklch(0.22 0.015 48);
  --border: oklch(0.29 0.018 48);
  --border-active: oklch(0.43 0.09 27);
  --ink: oklch(0.90 0.012 75);
  --ink-secondary: oklch(0.70 0.012 70);
  --ink-muted: oklch(0.56 0.01 68);
  --accent: oklch(0.50 0.17 25);
  --accent-bright: oklch(0.64 0.18 27);
  --accent-dim: oklch(0.34 0.09 25);
  --gold: oklch(0.74 0.13 85);
  --gold-dim: oklch(0.46 0.045 80);
  --ok: oklch(0.70 0.12 150);
  --font-display: "Hiragino Mincho ProN", "YuMincho", "Noto Serif JP", Georgia, serif;
  --font-body: system-ui, -apple-system, "Hiragino Kaku Gothic ProN", "Noto Sans", sans-serif;
  --font-mono: "SF Mono", ui-monospace, Menlo, monospace;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --page: min(1180px, calc(100vw - 40px));
}

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-width: 320px;
  min-height: 100dvh;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(circle at 78% 0%, oklch(0.24 0.03 78 / 0.22), transparent 34%);
  z-index: -1;
}

img { display: block; max-width: 100%; }
a { color: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }

:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 4px;
}

.skip-link {
  position: fixed;
  left: 16px;
  top: 12px;
  z-index: 20;
  transform: translateY(-160%);
  padding: 9px 13px;
  background: var(--ink);
  color: var(--bg);
  text-decoration: none;
  transition: transform 160ms var(--ease);
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  min-height: 64px;
  background: oklch(0.145 0.009 52 / 0.96);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(14px);
}

.nav-shell {
  width: var(--page);
  min-height: 64px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: clamp(20px, 4vw, 58px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  color: var(--ink);
  font-family: var(--font-display);
  font-size: 1.02rem;
  letter-spacing: 0.16em;
  text-decoration: none;
  white-space: nowrap;
}

.brand-mark {
  width: 27px;
  height: 27px;
  display: inline-grid;
  place-items: center;
  border-radius: 3px;
  background: var(--accent-dim);
  color: var(--ink);
  font-size: 0.8rem;
  letter-spacing: 0;
}

.site-nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: clamp(18px, 3vw, 34px);
  overflow-x: auto;
  scrollbar-width: none;
}

.site-nav::-webkit-scrollbar { display: none; }

.site-nav a {
  position: relative;
  padding: 21px 1px 19px;
  color: var(--ink-secondary);
  font-family: var(--font-display);
  font-size: 0.9rem;
  letter-spacing: 0.08em;
  text-decoration: none;
  white-space: nowrap;
  transition: color 160ms ease;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] { color: var(--ink); }

.site-nav a[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--gold);
}

.hero {
  width: var(--page);
  min-height: min(780px, calc(100dvh - 64px));
  margin: 0 auto;
  padding: clamp(36px, 6vw, 78px) 0;
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(420px, 0.92fr);
  align-items: center;
  gap: clamp(34px, 7vw, 96px);
}

.hero-copy { max-width: 620px; }

.hero-kicker {
  margin: 0 0 18px;
  color: var(--gold);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.hero h1 {
  margin: 0;
  max-width: none;
  font-family: var(--font-display);
  font-size: clamp(3rem, 4.8vw, 4.5rem);
  font-weight: 400;
  line-height: 1.02;
  letter-spacing: -0.025em;
  text-wrap: balance;
}

.hero-lede {
  max-width: 50ch;
  margin: 24px 0 0;
  color: var(--ink-secondary);
  font-size: clamp(1rem, 1.4vw, 1.15rem);
  line-height: 1.75;
  text-wrap: pretty;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 18px;
  border: 1px solid var(--accent-dim);
  border-radius: 4px;
  background: var(--accent-dim);
  color: var(--ink);
  font-weight: 620;
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
  transition: background 180ms ease, border-color 180ms ease, transform 180ms var(--ease);
}

.button:hover { background: var(--accent); border-color: var(--accent); }
.button:active { transform: translateY(1px); }

.button.secondary {
  border-color: var(--border);
  background: transparent;
  color: var(--ink-secondary);
}

.button.secondary:hover { border-color: var(--ink-muted); background: var(--surface); color: var(--ink); }

.hero-visual {
  position: relative;
  align-self: stretch;
  min-height: 500px;
  overflow: hidden;
  border-radius: 2px;
  background: var(--surface);
}

.hero-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: 56% center;
}

.hero-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, var(--bg), transparent 24%), linear-gradient(0deg, var(--bg) 0%, transparent 17%);
  pointer-events: none;
}

.visual-caption {
  position: absolute;
  right: 18px;
  bottom: 16px;
  z-index: 1;
  max-width: 26ch;
  margin: 0;
  color: var(--ink-secondary);
  font-size: 0.76rem;
  line-height: 1.5;
  text-align: right;
}

.fact-rail {
  width: var(--page);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.25fr 1fr 1fr 1fr;
  border-top: 1px solid var(--gold-dim);
  border-bottom: 1px solid var(--border);
}

.fact {
  min-height: 130px;
  padding: 24px clamp(18px, 2.5vw, 32px);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border-right: 1px solid var(--border);
}

.fact:last-child { border-right: 0; }
.fact strong { font-family: var(--font-display); font-size: clamp(1.05rem, 1.8vw, 1.35rem); font-weight: 400; }
.fact span { color: var(--ink-muted); font-size: 0.76rem; line-height: 1.5; }
.fact:first-child strong { color: var(--gold); }

.section {
  width: var(--page);
  margin: 0 auto;
  padding: clamp(84px, 11vw, 150px) 0;
}

.section + .section { border-top: 1px solid var(--border); }

.section h2 {
  max-width: 16ch;
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(2.1rem, 4.8vw, 4.5rem);
  font-weight: 400;
  line-height: 1.08;
  letter-spacing: -0.02em;
  text-wrap: balance;
}

.section-intro {
  max-width: 65ch;
  margin: 26px 0 0;
  color: var(--ink-secondary);
  font-size: 1.06rem;
  text-wrap: pretty;
}

.definition-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(340px, 0.9fr);
  gap: clamp(50px, 9vw, 120px);
  align-items: start;
}

.definition-copy p {
  max-width: 66ch;
  margin: 28px 0 0;
  color: var(--ink-secondary);
}

.definition-copy p:first-of-type { color: var(--ink); font-size: 1.12rem; }

.business-model {
  padding: 6px 0 0;
  border-top: 1px solid var(--gold-dim);
}

.business-model div {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 20px;
  padding: 18px 0;
  border-bottom: 1px solid var(--border);
}

.business-model dt { color: var(--ink-muted); font-family: var(--font-mono); font-size: 0.72rem; }
.business-model dd { margin: 0; color: var(--ink); }

.standards {
  margin-top: 54px;
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(300px, 0.88fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
}

.standard-panel {
  padding: clamp(26px, 5vw, 58px);
  background: var(--bg-raised);
}

.standard-panel.excluded { background: oklch(0.145 0.012 35); }

.standard-panel h3 {
  margin: 0 0 28px;
  color: var(--gold);
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 400;
}

.standard-panel.excluded h3 { color: var(--accent-bright); }

.standard-list { list-style: none; margin: 0; padding: 0; }

.standard-list li {
  position: relative;
  padding: 14px 0 14px 28px;
  color: var(--ink-secondary);
  border-bottom: 1px solid var(--border);
}

.standard-list li:last-child { border-bottom: 0; }

.standard-list li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 24px;
  width: 10px;
  height: 1px;
  background: var(--gold);
}

.excluded .standard-list li::before { background: var(--accent-bright); }

.safety-stage {
  margin-top: 58px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
}

.safety-step {
  min-height: 260px;
  padding: 26px 24px;
  border-top: 1px solid var(--gold-dim);
  border-right: 1px solid var(--border);
}

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

.safety-step .step-index {
  color: var(--gold);
  font-family: var(--font-mono);
  font-size: 0.72rem;
}

.safety-step h3 {
  margin: 52px 0 12px;
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 400;
}

.safety-step p { margin: 0; color: var(--ink-secondary); font-size: 0.92rem; }

.ethics-section {
  display: grid;
  grid-template-columns: minmax(300px, 0.85fr) minmax(0, 1.15fr);
  gap: clamp(56px, 10vw, 140px);
  align-items: start;
}

.ethics-statement {
  position: sticky;
  top: 112px;
}

.ethics-statement h2 { max-width: 12ch; }

.ethics-statement p {
  max-width: 44ch;
  margin: 28px 0 0;
  color: var(--ink-secondary);
  font-size: 1.05rem;
}

.ethics-principles {
  border-top: 1px solid var(--gold-dim);
}

.ethics-principles article {
  display: grid;
  grid-template-columns: minmax(150px, 0.42fr) minmax(0, 1fr);
  gap: clamp(22px, 4vw, 54px);
  padding: 26px 0 30px;
  border-bottom: 1px solid var(--border);
}

.ethics-principles h3 {
  margin: 0;
  color: var(--ink);
  font-family: var(--font-display);
  font-size: 1.08rem;
  font-weight: 400;
}

.ethics-principles p { margin: 0; color: var(--ink-secondary); }

.reviewer-panel {
  position: relative;
  overflow: hidden;
  padding: clamp(34px, 7vw, 76px);
  background: var(--surface);
  border-top: 1px solid var(--gold-dim);
}

.reviewer-panel::after {
  content: "縛";
  position: absolute;
  right: -0.04em;
  bottom: -0.29em;
  color: oklch(0.74 0.13 85 / 0.055);
  font-family: var(--font-display);
  font-size: clamp(13rem, 28vw, 28rem);
  line-height: 1;
  pointer-events: none;
}

.reviewer-content { position: relative; z-index: 1; max-width: 820px; }
.reviewer-content h2 { max-width: 14ch; }
.reviewer-content p { max-width: 64ch; margin: 24px 0 0; color: var(--ink-secondary); }

.reviewer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.site-footer {
  width: var(--page);
  margin: 0 auto;
  padding: 30px 0 44px;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 28px;
  border-top: 1px solid var(--border);
  color: var(--ink-muted);
  font-size: 0.78rem;
}

.footer-links { display: flex; flex-wrap: wrap; gap: 20px; }
.footer-links a:hover { color: var(--ink); }

.legal-hero {
  width: var(--page);
  margin: 0 auto;
  padding: clamp(68px, 11vw, 130px) 0 clamp(52px, 8vw, 90px);
  border-bottom: 1px solid var(--border);
}

.legal-hero p:first-child {
  margin: 0 0 18px;
  color: var(--gold);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.legal-hero h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 6vw, 5.5rem);
  font-weight: 400;
  line-height: 1;
  letter-spacing: -0.025em;
}

.legal-hero .legal-summary { max-width: 62ch; margin: 24px 0 0; color: var(--ink-secondary); }
.legal-updated { margin: 22px 0 0; color: var(--ink-muted); font-size: 0.8rem; }

.legal-layout {
  width: var(--page);
  margin: 0 auto;
  padding: 64px 0 120px;
  display: grid;
  grid-template-columns: 230px minmax(0, 720px);
  gap: clamp(44px, 8vw, 100px);
  justify-content: center;
}

.legal-toc { position: sticky; top: 100px; align-self: start; }
.legal-toc strong { display: block; margin-bottom: 12px; color: var(--ink); font-family: var(--font-display); font-weight: 400; }
.legal-toc a { display: block; padding: 6px 0; color: var(--ink-muted); font-size: 0.82rem; text-decoration: none; }
.legal-toc a:hover { color: var(--gold); }

.legal-copy { min-width: 0; }
.legal-copy section { scroll-margin-top: 100px; padding: 0 0 48px; }
.legal-copy section + section { padding-top: 46px; border-top: 1px solid var(--border); }

.legal-copy h2 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-size: clamp(1.45rem, 3vw, 2.1rem);
  font-weight: 400;
  line-height: 1.25;
}

.legal-copy h3 { margin: 26px 0 10px; color: var(--ink); font-size: 1rem; }
.legal-copy p { margin: 0 0 16px; color: var(--ink-secondary); }
.legal-copy ul { margin: 12px 0 18px; padding-left: 1.2rem; color: var(--ink-secondary); }
.legal-copy li { margin: 8px 0; padding-left: 6px; }
.legal-copy a { color: var(--gold); text-underline-offset: 3px; }

.notice {
  margin: 4px 0 24px;
  padding: 20px 22px;
  background: var(--surface);
  border: 1px solid var(--gold-dim);
  border-radius: 2px;
  color: var(--ink-secondary);
}

.notice strong { color: var(--ink); }

@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; min-height: auto; }
  .hero-copy { padding-top: 24px; }
  .hero h1 { max-width: 14ch; }
  .hero-visual { min-height: auto; aspect-ratio: 16 / 10; }
  .fact-rail { grid-template-columns: 1fr 1fr; }
  .fact:nth-child(2) { border-right: 0; }
  .fact:nth-child(-n+2) { border-bottom: 1px solid var(--border); }
  .definition-layout { grid-template-columns: 1fr; }
  .standards { grid-template-columns: 1fr; }
  .safety-stage { grid-template-columns: 1fr 1fr; }
  .safety-step:nth-child(2) { border-right: 0; }
  .safety-step:nth-child(-n+2) { border-bottom: 1px solid var(--border); }
  .legal-layout { grid-template-columns: 1fr; }
  .ethics-section { grid-template-columns: 1fr; }
  .ethics-statement { position: static; }
  .legal-toc { position: static; padding-bottom: 28px; border-bottom: 1px solid var(--border); }
  .legal-toc nav { columns: 2; }
}

@media (max-width: 620px) {
  :root { --page: min(100% - 28px, 1180px); }
  .nav-shell { gap: 18px; }
  .brand { font-size: 0.9rem; }
  .brand-mark { width: 25px; height: 25px; }
  .site-nav { gap: 18px; }
  .site-nav a { font-size: 0.82rem; }
  .hero { padding-top: 42px; gap: 32px; }
  .hero h1 { font-size: clamp(2.7rem, 14vw, 4.2rem); }
  .hero-actions, .reviewer-links { align-items: stretch; flex-direction: column; }
  .button { width: 100%; }
  .hero-visual { aspect-ratio: 4 / 5; }
  .hero-visual img { object-position: 63% center; }
  .hero-visual::after { background: linear-gradient(0deg, var(--bg), transparent 20%); }
  .fact-rail { grid-template-columns: 1fr; }
  .fact { min-height: 108px; border-right: 0; border-bottom: 1px solid var(--border); }
  .fact:last-child { border-bottom: 0; }
  .section { padding: 78px 0; }
  .section h2 { font-size: clamp(2.3rem, 12vw, 3.6rem); }
  .business-model div { grid-template-columns: 1fr; gap: 5px; }
  .safety-stage { grid-template-columns: 1fr; }
  .safety-step { min-height: auto; border-right: 0; border-bottom: 1px solid var(--border); }
  .safety-step:last-child { border-bottom: 0; }
  .safety-step h3 { margin-top: 28px; }
  .ethics-principles article { grid-template-columns: 1fr; gap: 9px; }
  .site-footer { flex-direction: column; }
  .legal-toc nav { columns: 1; }
}

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

@media print {
  :root { color-scheme: light; }
  body { background: white; color: #111; font-size: 11pt; }
  body::before, .site-header, .site-footer, .legal-toc { display: none; }
  .legal-hero, .legal-layout { width: 100%; padding: 24px 0; display: block; }
  .legal-hero p, .legal-copy p, .legal-copy ul { color: #333; }
  .legal-copy section { break-inside: avoid; }
}