:root {
  color-scheme: light;
  --ink: #17202a;
  --muted: #566372;
  --paper: #f7f8fa;
  --white: #ffffff;
  --line: #cbd5e1;
  --navy: #17324d;
  --teal: #0f766e;
  --green: #427a46;
  --orange: #ea580c;
  --blue: #2563eb;
  --red: #b42318;
  --soft-blue: #eff6ff;
  --soft-green: #ecfdf5;
  --soft-orange: #fff7ed;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Meiryo", "Yu Gothic", "Segoe UI", system-ui, sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.86;
  letter-spacing: 0;
}
a { color: inherit; }
img { max-width: 100%; height: auto; }
.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(247,248,250,.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}
.topbar-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 10px 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand { font-weight: 800; color: var(--navy); font-size: 14px; }
.nav { display: flex; flex-wrap: wrap; gap: 8px; justify-content: flex-end; }
.nav a {
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 10px;
  background: #fff;
  font-size: 12px;
  color: #334155;
}
.hero {
  background: linear-gradient(135deg, #17324d 0%, #0f766e 62%, #427a46 100%);
  color: #fff;
  border-bottom: 6px solid var(--orange);
}
.hero-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 48px 18px 42px;
}
.eyebrow {
  margin: 0 0 8px;
  font-size: 13px;
  font-weight: 800;
  color: inherit;
  opacity: .9;
}
h1 {
  margin: 0 0 14px;
  font-size: clamp(30px, 4.2vw, 48px);
  line-height: 1.1;
  letter-spacing: 0;
  max-width: 980px;
}
.lead { max-width: 760px; font-size: clamp(18px, 2vw, 21px); line-height: 1.75; opacity: .98; }
.hero-sublead {
  max-width: 760px;
  margin: 8px 0 0;
  font-size: 15px;
  line-height: 1.9;
  opacity: .9;
}
main {
  max-width: 1120px;
  margin: 0 auto;
  padding: 26px 18px 64px;
}
main.article-layout {
  max-width: 1180px;
  display: grid;
  grid-template-columns: minmax(0, 760px) 260px;
  gap: 48px;
  align-items: start;
}
.article-body {
  min-width: 0;
}
.article-aside {
  position: sticky;
  top: 72px;
}
.band,
.article-card,
.panel,
.section,
.claim-card,
figure {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
}
.band, .panel, .section { padding: 22px; margin: 18px 0; }
.section h2, .panel h2 {
  margin: 0 0 12px;
  color: var(--navy);
  font-size: 25px;
  line-height: 1.3;
}
.article-card {
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  gap: 18px;
  padding: 18px;
  text-decoration: none;
  align-items: center;
}
.article-card h2 { margin: 4px 0 8px; color: var(--navy); font-size: 25px; line-height: 1.25; }
.article-card p { margin: 8px 0; color: var(--muted); }
.badge {
  display: inline-flex;
  width: fit-content;
  border-radius: 999px;
  padding: 4px 10px;
  background: var(--soft-green);
  border: 1px solid #a7f3d0;
  color: #166534;
  font-size: 12px;
  font-weight: 800;
}
.grid-2 { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px; }
.toc { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.toc a {
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 10px;
  background: #fff;
  font-size: 12px;
  color: #334155;
}
.article-aside .toc {
  display: block;
  margin: 0;
  padding: 16px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
}
.article-aside .toc strong {
  display: block;
  margin: 0 0 8px;
  color: var(--navy);
  font-size: 13px;
}
.article-aside .toc a {
  display: block;
  border: 0;
  border-left: 3px solid transparent;
  border-radius: 0;
  background: transparent;
  padding: 7px 0 7px 12px;
  color: #334155;
}
.article-aside .toc a:hover {
  border-left-color: var(--orange);
  color: var(--orange);
}
.article-aside .side-note {
  margin-top: 14px;
  padding: 14px 16px;
  background: var(--soft-orange);
  border: 1px solid #fed7aa;
  border-radius: 8px;
  color: #7c2d12;
  font-size: 13px;
  line-height: 1.75;
}
figure { margin: 18px 0; overflow: hidden; }
figure img { display: block; width: 100%; background: #fff; }
figcaption {
  padding: 11px 13px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}
.callout {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 15px 16px;
  margin: 16px 0;
}
.callout h3 { margin: 0 0 8px; font-size: 16px; }
.method { background: var(--soft-green); border-color: #a7f3d0; }
.warn { background: #fef2f2; border-color: #fecaca; }
.note { background: var(--soft-blue); border-color: #bfdbfe; }
.literature { background: var(--soft-orange); border-color: #fed7aa; }
.table-wrap { overflow-x: auto; margin: 16px 0; }
table { width: 100%; border-collapse: collapse; min-width: 680px; font-size: 14px; }
th, td { border: 1px solid var(--line); padding: 9px 10px; vertical-align: top; }
th { background: #f1f5f9; text-align: left; }
.claim-card { padding: 16px; }
.claim-card h3 { margin: 0 0 8px; color: var(--navy); }
.refs li, .questions li { margin: 8px 0; overflow-wrap: anywhere; }
.footer {
  margin-top: 34px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
}
code {
  background: #f1f5f9;
  border-radius: 4px;
  padding: 2px 5px;
  overflow-wrap: anywhere;
}
.hero code {
  color: var(--navy);
}
.article-body .section {
  background: transparent;
  border: 0;
  border-top: 1px solid var(--line);
  border-radius: 0;
  padding: 34px 0;
  margin: 0;
}
.article-body .section h2 {
  padding-left: 14px;
  border-left: 4px solid var(--orange);
  font-size: 28px;
  line-height: 1.35;
}
.article-body .section h3 {
  margin: 24px 0 8px;
  color: var(--navy);
  font-size: 18px;
  line-height: 1.45;
}
.article-body p,
.article-body li {
  max-width: 42em;
  font-size: 16.5px;
  line-height: 2;
}
.article-body .takeaway {
  max-width: 42em;
  padding: 16px 18px;
  background: var(--soft-orange);
  border-left: 5px solid var(--orange);
  color: #7c2d12;
  font-weight: 800;
}
.article-body figure {
  margin: 32px 0;
}
.article-body figure img {
  border-radius: 6px 6px 0 0;
}
.article-body .callout {
  border: 0;
  border-left: 5px solid var(--orange);
  border-radius: 0;
  padding: 14px 18px;
}
.formula-card {
  margin: 18px 0;
  padding: 18px;
  background: #fff;
  border: 1px solid var(--line);
  border-left: 6px solid var(--orange);
  border-radius: 8px;
}
.formula {
  margin: 10px 0 14px;
  padding: 14px 16px;
  background: #0f172a;
  color: #fff;
  border-radius: 6px;
  font-family: "Segoe UI", "Meiryo", sans-serif;
  font-size: clamp(17px, 2.4vw, 24px);
  line-height: 1.65;
  overflow-x: auto;
}
.term-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}
.term {
  padding: 12px 13px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
}
.term strong {
  color: var(--navy);
}
.orange-rule {
  height: 4px;
  width: 86px;
  background: var(--orange);
  border-radius: 999px;
  margin: 12px 0 18px;
}
.section-risk h2 {
  border-left-color: var(--red);
}
.deep-toggle {
  margin: 16px 0;
  background: #fff;
  border: 1px solid var(--line);
  border-left: 5px solid var(--orange);
  border-radius: 8px;
  padding: 0;
}
.deep-toggle summary {
  cursor: pointer;
  padding: 12px 15px;
  font-weight: 800;
  color: var(--navy);
}
.deep-toggle[open] summary {
  border-bottom: 1px solid var(--line);
  background: var(--soft-orange);
}
.deep-toggle > div {
  padding: 14px 16px 16px;
}
.split-note {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}
.split-note > div {
  padding: 13px 14px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
}
table {
  line-height: 1.65;
}
th {
  background: var(--soft-orange);
  color: var(--navy);
}
td:first-child {
  font-weight: 700;
  color: var(--navy);
}
@media (max-width: 860px) {
  .topbar-inner { align-items: flex-start; flex-direction: column; }
  .article-card, .grid-2, .grid-3 { grid-template-columns: 1fr; }
  main.article-layout { display: block; }
  .article-aside { position: static; margin-bottom: 20px; }
  .term-grid { grid-template-columns: 1fr; }
  .split-note { grid-template-columns: 1fr; }
  .nav { justify-content: flex-start; }
}