:root {
  --ink: #111a2f;
  --muted: #5e6573;
  --paper: #f4f2ec;
  --card: #fbfaf6;
  --line: #c8c9c2;
  --acid: #cbff45;
  --acid-dark: #a9df20;
  --navy: #17213b;
  --white: #fff;
  --shadow: 7px 7px 0 var(--ink);
  --max: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Hiragino Sans", "Yu Gothic", "Meiryo", system-ui, sans-serif;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-underline-offset: .22em; }
.skip-link { position: fixed; top: -100px; left: 1rem; z-index: 20; padding: .7rem 1rem; background: var(--acid); }
.skip-link:focus { top: 1rem; }

.site-header {
  width: min(calc(100% - 48px), var(--max));
  min-height: 88px;
  margin: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  border-bottom: 1px solid var(--line);
}
.brand { display: inline-flex; align-items: center; gap: .7rem; font-weight: 800; text-decoration: none; letter-spacing: -.03em; }
.brand-mark { display: inline-grid; place-items: center; width: 40px; height: 32px; background: var(--acid); border: 2px solid var(--ink); font: 500 .9rem "DM Mono", monospace; }
.site-header nav, .site-footer nav { display: flex; flex-wrap: wrap; gap: 1.6rem; font-size: .86rem; font-weight: 600; }
.site-header nav a { text-decoration: none; }
.site-header nav a:hover, .site-header nav a[aria-current="page"] { text-decoration: underline; text-decoration-thickness: 3px; text-decoration-color: var(--acid-dark); }

.hero { width: min(calc(100% - 48px), var(--max)); margin: auto; padding: 92px 0 38px; }
.eyebrow, .kicker { font: 500 .76rem ui-monospace, "SFMono-Regular", Consolas, monospace; letter-spacing: .12em; text-transform: uppercase; }
.eyebrow { display: inline-block; padding: .38rem .75rem; color: var(--white); background: var(--navy); }
.hero h1 { max-width: 1000px; margin: 26px 0; font-size: clamp(3.2rem, 6vw, 5.4rem); line-height: 1.06; letter-spacing: -.075em; }
.hero h1 span { position: relative; z-index: 0; }
.hero h1 span::after { content: ""; position: absolute; z-index: -1; left: 0; right: 0; bottom: .05em; height: .22em; background: var(--acid); }
.hero-copy { max-width: 720px; margin: 0; color: var(--muted); font-size: clamp(1rem, 2vw, 1.25rem); }
.hero-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 1.8rem; margin: 38px 0 70px; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 1rem; min-height: 54px; padding: .7rem 1.35rem; border: 2px solid var(--ink); font: 700 .95rem "Hiragino Sans", "Yu Gothic", sans-serif; text-decoration: none; cursor: pointer; }
.button-primary { background: var(--acid); box-shadow: 5px 5px 0 var(--ink); }
.button-primary:hover { transform: translate(2px, 2px); box-shadow: 3px 3px 0 var(--ink); }
.text-link { font-weight: 700; text-decoration-thickness: 2px; }
.proof-strip { display: grid; grid-template-columns: repeat(4, 1fr); margin: 0; border: 1px solid var(--line); border-width: 1px 0; }
.proof-strip div { padding: 20px 24px; border-right: 1px solid var(--line); }
.proof-strip div:last-child { border: 0; }
.proof-strip dt { color: var(--muted); font: .68rem "DM Mono", monospace; }
.proof-strip dd { margin: 2px 0 0; font-weight: 700; }

.section { width: min(calc(100% - 48px), var(--max)); margin: auto; padding: 110px 0; border-bottom: 1px solid var(--line); }
.section-heading { display: grid; grid-template-columns: .35fr 1fr; gap: 12px 50px; align-items: start; margin-bottom: 48px; }
.section-heading .kicker { grid-row: 1 / span 2; }
.section-heading h2, .split-section h2, .source-note h2 { margin: 0; font-size: clamp(2rem, 4vw, 3.7rem); line-height: 1.25; letter-spacing: -.055em; }
.section-heading > p:last-child { margin: 0; color: var(--muted); }
.decision-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.decision-card { position: relative; min-height: 340px; padding: 30px; background: var(--card); border: 1.5px solid var(--ink); display: flex; flex-direction: column; align-items: flex-start; }
.decision-card.featured { background: var(--acid); box-shadow: var(--shadow); }
.card-number { position: absolute; top: 18px; right: 22px; font: 500 1rem "DM Mono", monospace; }
.decision-card .tag { margin: 0 0 50px; padding: .25rem .55rem; color: var(--white); background: var(--navy); font: .68rem "DM Mono", monospace; }
.decision-card h3 { margin: 0 0 12px; font-size: 1.45rem; line-height: 1.4; letter-spacing: -.03em; }
.decision-card p:not(.tag) { color: #424a58; }
.decision-card a, .decision-card .status { margin-top: auto; font-size: .84rem; font-weight: 700; }
.status { color: var(--muted); }

.split-section { display: grid; grid-template-columns: .8fr 1.2fr; gap: 10%; }
.rules-list > div { display: grid; grid-template-columns: 42px 1fr; gap: 18px; padding: 24px 0; border-top: 1px solid var(--line); }
.rules-list > div span { display: grid; place-items: center; width: 34px; height: 34px; border: 1.5px solid var(--ink); background: var(--acid); font-weight: 800; }
.rules-list p { margin: 0; color: var(--muted); }
.rules-list strong { display: block; margin-bottom: 3px; color: var(--ink); }
.source-note { display: grid; grid-template-columns: .35fr 1fr; gap: 50px; }
.source-note > div > p { max-width: 780px; color: var(--muted); }
.source-line { color: var(--muted); font-size: .76rem; }
.table-scroll { max-width: 100%; overflow-x: auto; }
.comparison-table { width: 100%; min-width: 680px; border-collapse: collapse; background: var(--card); }
.comparison-table th, .comparison-table td { padding: 18px; border: 1px solid var(--line); text-align: left; vertical-align: top; font-size: .9rem; }
.comparison-table thead th { color: var(--white); background: var(--navy); }
.comparison-table tbody th { width: 150px; background: #e8e7de; }
.article-section.wide-section { max-width: none; }

.article-shell { width: min(calc(100% - 48px), var(--max)); margin: auto; padding: 72px 0 110px; }
.article-shell.narrow { max-width: 880px; }
.article-header { max-width: 880px; margin-bottom: 70px; }
.article-header h1 { margin: 10px 0 16px; font-size: clamp(2.7rem, 7vw, 5.7rem); line-height: 1.12; letter-spacing: -.065em; }
.article-header > p:last-child { max-width: 690px; color: var(--muted); font-size: 1.05rem; }
.breadcrumb { display: flex; flex-wrap: wrap; gap: .55rem; margin-bottom: 32px; color: var(--muted); font-size: .78rem; }
.article-meta { display: flex; flex-wrap: wrap; gap: .55rem 1.2rem; margin-top: 22px; color: var(--muted); font-size: .75rem; }
.article-meta span { padding: .25rem .55rem; border: 1px solid var(--line); background: var(--card); }
.calculator-layout { display: grid; grid-template-columns: 1.25fr .75fr; gap: 32px; align-items: start; }
.calculator { padding: 36px; background: var(--card); border: 1.5px solid var(--ink); }
.calculator fieldset { margin: 0 0 36px; padding: 0; border: 0; }
.calculator legend { width: 100%; margin-bottom: 16px; padding-bottom: 10px; border-bottom: 1px solid var(--line); font-size: 1.15rem; font-weight: 800; }
.calculator legend span { margin-right: 12px; color: var(--muted); font: .8rem "DM Mono", monospace; }
.calculator label { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 10px 0; font-size: .9rem; }
.field { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: .75rem; }
.field input { width: 120px; padding: .65rem .7rem; border: 1.5px solid var(--ink); background: var(--white); font: 500 1rem "DM Mono", monospace; text-align: right; }
.field input:focus { outline: 3px solid var(--acid-dark); outline-offset: 2px; }
.calculator .button { width: 100%; }
.result-panel { position: sticky; top: 20px; padding: 34px; color: var(--white); background: var(--navy); border: 1.5px solid var(--ink); box-shadow: 7px 7px 0 var(--acid-dark); }
.result-main, .result-sub { display: flex; align-items: baseline; justify-content: space-between; gap: 15px; }
.result-main { padding: 25px 0; }
.result-main strong { font: 500 clamp(2.1rem, 4vw, 3.4rem) "DM Mono", monospace; letter-spacing: -.06em; }
.result-sub { padding: 13px 0; border-top: 1px solid #48516a; font-size: .84rem; }
.result-sub strong { font: 500 1rem "DM Mono", monospace; }
.result-panel hr { border: 0; border-top: 1px solid #48516a; margin: 24px 0; }
.result-panel > p:last-child { color: #c9ced9; font-size: .8rem; }
.article-section { max-width: 840px; margin: 90px auto 0; }
.article-section h2 { margin: 64px 0 18px; font-size: clamp(1.55rem, 3vw, 2.25rem); letter-spacing: -.04em; }
.article-section p, .article-section li { color: #474e5b; }
.article-section h3 { margin: 0 0 6px; font-size: 1.08rem; }
.callout { margin: 22px 0; padding: 20px 24px; background: var(--card); border-left: 6px solid var(--acid-dark); }
.callout p { margin: 0; }
.check-list { padding: 0; list-style: none; }
.check-list li { position: relative; padding: 14px 0 14px 38px; border-bottom: 1px solid var(--line); }
.check-list li::before { content: "✓"; position: absolute; left: 4px; color: var(--ink); font-weight: 800; }
.prose ol { padding-left: 1.4rem; }
.prose li { padding: .35rem 0; }
.formula { display: grid; gap: 8px; margin: 24px 0; padding: 24px; color: var(--white); background: var(--navy); border: 1.5px solid var(--ink); box-shadow: 6px 6px 0 var(--acid-dark); }
.formula strong { font-size: clamp(1rem, 2vw, 1.25rem); line-height: 1.6; }
.formula span { color: #c9ced9; font-size: .78rem; }
.scenario-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin: 28px 0; }
.scenario-grid article { padding: 22px; background: var(--card); border: 1px solid var(--line); }
.scenario-grid span, .scenario-grid strong { display: block; }
.scenario-grid span { color: var(--muted); font-size: .78rem; }
.scenario-grid strong { margin: 5px 0; font: 600 1.25rem ui-monospace, "SFMono-Regular", Consolas, monospace; }
.scenario-grid p { margin: 0; font-size: .75rem; }
.signal-list { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin: 28px 0; }
.signal-list article { display: grid; grid-template-columns: 38px 1fr; gap: 15px; padding: 22px; background: var(--card); border: 1px solid var(--line); }
.signal-list article > span { display: grid; place-items: center; width: 34px; height: 34px; background: var(--acid); border: 1.5px solid var(--ink); font: 700 .72rem ui-monospace, monospace; }
.signal-list p { margin: 0; font-size: .88rem; }
.decision-links { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin: 28px 0; }
.decision-links a { display: grid; gap: 6px; min-height: 140px; padding: 22px; background: var(--card); border: 1.5px solid var(--ink); text-decoration: none; }
.decision-links a:hover { background: var(--acid); }
.decision-links span { color: var(--muted); font-size: .82rem; }
.methodology { padding: 30px; background: #e8e7de; border: 1px solid var(--line); }
.methodology h2 { margin-top: 0; }
.guide-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.guide-card { display: flex; flex-direction: column; min-height: 250px; padding: 26px; background: var(--card); border: 1.5px solid var(--ink); }
.guide-card .tag { align-self: flex-start; margin: 0 0 28px; padding: .25rem .55rem; color: var(--white); background: var(--navy); font: .68rem ui-monospace, monospace; }
.guide-card h3 { margin: 0 0 10px; font-size: 1.35rem; line-height: 1.45; }
.guide-card p:not(.tag) { margin: 0; color: var(--muted); font-size: .9rem; }
.guide-card a { margin-top: auto; padding-top: 20px; font-weight: 700; }

.site-footer { width: min(calc(100% - 48px), var(--max)); margin: 0 auto; padding: 56px 0 70px; display: grid; grid-template-columns: 1fr 1fr; gap: 15px 40px; align-items: center; }
.site-footer > div { display: flex; align-items: center; gap: 10px; }
.site-footer p { margin: 0; color: var(--muted); font-size: .84rem; }
.site-footer nav { grid-column: 2; grid-row: 1 / span 2; justify-content: flex-end; }
.not-found { min-height: 100vh; width: min(calc(100% - 48px), 800px); margin: auto; display: flex; flex-direction: column; justify-content: center; align-items: flex-start; }
.not-found h1 { margin: 10px 0; font-size: clamp(3rem, 8vw, 6rem); line-height: 1.12; letter-spacing: -.07em; }
.not-found .button { margin-top: 20px; }

@media (max-width: 800px) {
  .site-header { width: min(calc(100% - 32px), var(--max)); min-height: 72px; padding: 16px 0; align-items: flex-start; flex-direction: column; gap: 12px; }
  .site-header nav { gap: .65rem 1.2rem; }
  .hero, .section, .article-shell, .site-footer { width: min(calc(100% - 32px), var(--max)); }
  .hero { padding-top: 62px; }
  .hero h1 { font-size: clamp(3rem, 15vw, 5rem); }
  .proof-strip { grid-template-columns: 1fr 1fr; }
  .proof-strip div:nth-child(2) { border-right: 0; }
  .proof-strip div:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .section { padding: 78px 0; }
  .section-heading, .source-note, .split-section { grid-template-columns: 1fr; gap: 24px; }
  .section-heading .kicker { grid-row: auto; }
  .decision-grid { grid-template-columns: 1fr; }
  .decision-card { min-height: 300px; }
  .calculator-layout { grid-template-columns: 1fr; }
  .scenario-grid, .decision-links { grid-template-columns: 1fr; }
  .signal-list, .guide-grid { grid-template-columns: 1fr; }
  .result-panel { position: static; }
  .site-footer { grid-template-columns: 1fr; }
  .site-footer nav { grid-column: 1; grid-row: auto; justify-content: flex-start; }
}

@media (max-width: 500px) {
  .proof-strip { grid-template-columns: 1fr; }
  .proof-strip div { border-right: 0; border-bottom: 1px solid var(--line); }
  .hero-actions { align-items: stretch; flex-direction: column; }
  .calculator { padding: 24px 18px; }
  .calculator label { align-items: flex-start; flex-direction: column; gap: 5px; }
  .field { width: 100%; }
  .field input { flex: 1; }
}

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