:root {
  --color-main: #4f78a8;
  --color-main-dark: #2f5687;
  --color-accent: #8bbeb2;
  --color-warning: #c98f5b;
  --color-bg: #f4f7fb;
  --color-surface: #ffffff;
  --color-soft: #eaf1f8;
  --color-border: #d5e0ec;
  --color-text: #27313d;
  --color-muted: #647282;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--color-text);
  font-family: "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
  line-height: 1.85;
  background: var(--color-bg);
}
a { color: var(--color-main-dark); }
.site-header, .site-footer {
  width: min(100%, 1040px);
  margin: 0 auto;
  padding: 16px 20px;
  background: var(--color-surface);
}
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border-bottom: 1px solid var(--color-border);
}
.brand {
  color: var(--color-main-dark);
  font-size: 22px;
  font-weight: 900;
  text-decoration: none;
}
.global-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 14px;
}
.global-nav a, .site-footer a { text-decoration: none; }
main {
  width: min(100%, 1040px);
  margin: 0 auto;
  padding: 22px 20px 42px;
  background: var(--color-surface);
}
.home-rich {
  background: linear-gradient(180deg, #eaf1f8 0, #f4f7fb 340px, #fff 340px);
}
.home-rich .site-header,
.article-rich .site-header {
  margin-top: 14px;
  border: 1px solid var(--color-border);
  border-radius: 8px 8px 0 0;
}
.home-rich main,
.article-rich main {
  padding: 28px clamp(18px, 4vw, 44px) 54px;
  border-right: 1px solid var(--color-border);
  border-left: 1px solid var(--color-border);
}
.home-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.92fr);
  gap: 18px 30px;
  align-items: start;
  padding: 28px;
  background: #fbfdff;
  border: 1px solid var(--color-border);
  border-left: 8px solid var(--color-main);
  border-radius: 8px;
  box-shadow: 0 12px 30px rgba(47, 86, 135, 0.08);
}
.label {
  display: inline-block;
  margin: 0 0 10px;
  padding: 3px 10px;
  color: var(--color-main-dark);
  background: #fff;
  border: 1px solid var(--color-border);
  font-size: 13px;
  font-weight: 700;
}
.home-hero .label { grid-column: 1 / -1; width: fit-content; margin-bottom: 0; }
h1 {
  margin: 0 0 12px;
  color: var(--color-main-dark);
  font-size: clamp(28px, 5vw, 44px);
  line-height: 1.35;
  letter-spacing: 0;
}
.home-hero h1 {
  grid-column: 1 / -1;
  max-width: 980px;
  margin-bottom: 6px;
  font-size: clamp(32px, 5vw, 50px);
}
h2 {
  margin: 0 0 12px;
  color: var(--color-main-dark);
  font-size: 24px;
  line-height: 1.45;
  letter-spacing: 0;
}
h3 {
  margin: 22px 0 8px;
  color: #33445a;
  font-size: 19px;
  line-height: 1.5;
}
.lead {
  max-width: 760px;
  margin: 0;
  font-size: 18px;
  font-weight: 700;
}
.home-hero-text { grid-column: 1; }
.home-hero .lead { max-width: 680px; }
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}
.button {
  display: inline-block;
  margin-top: 10px;
  padding: 10px 16px;
  color: #fff;
  background: var(--color-main-dark);
  font-weight: 700;
  text-decoration: none;
}
.button-secondary {
  color: var(--color-main-dark);
  background: #fff;
  border: 1px solid var(--color-main-dark);
}
.hero-visual {
  grid-column: 2;
  align-self: end;
  margin: 0;
  padding-top: 18px;
}
.hero-visual img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  box-shadow: 0 14px 34px rgba(39, 49, 61, 0.1);
}
section, .article-block { margin-top: 28px; }
.home-summary, .reading-flow, .decision-map, .check-axis, .cluster-links, .home-note, .cta-box, .intro-answer, .note-box {
  padding: 22px;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: 8px;
}
.home-summary h2, .reading-flow h2, .decision-map h2, .check-axis h2, .cluster-links h2, .home-note h2,
.article-block h2, .faq h2, .related-links h2, .cta-box h2 {
  position: relative;
  padding: 0 0 12px 18px;
  border-bottom: 1px solid var(--color-border);
}
.home-summary h2::before, .reading-flow h2::before, .decision-map h2::before, .check-axis h2::before, .cluster-links h2::before, .home-note h2::before,
.article-block h2::before, .faq h2::before, .related-links h2::before, .cta-box h2::before {
  position: absolute;
  top: 0.28em;
  left: 0;
  width: 6px;
  height: 1.2em;
  background: var(--color-accent);
  border-radius: 999px;
  content: "";
}
.summary-columns, .category-grid, .article-list, .related-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}
.summary-columns { grid-template-columns: repeat(3, minmax(0, 1fr)); margin-top: 18px; }
.summary-columns div, .card, .article-card {
  display: block;
  padding: 16px;
  color: var(--color-text);
  background: #fbfdff;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  text-decoration: none;
}
.summary-columns strong, .card strong, .article-card strong {
  display: block;
  margin-bottom: 6px;
  color: var(--color-main-dark);
  font-size: 18px;
}
.summary-columns span, .card span, .article-card span {
  display: block;
  color: var(--color-muted);
  font-size: 14px;
}
.reading-flow ol {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
  counter-reset: flow;
}
.reading-flow li { counter-increment: flow; }
.reading-flow a {
  position: relative;
  display: block;
  min-height: 100%;
  padding: 46px 16px 16px;
  color: var(--color-text);
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  text-decoration: none;
}
.reading-flow a::before {
  position: absolute;
  top: 14px;
  left: 16px;
  display: grid;
  width: 26px;
  height: 26px;
  place-items: center;
  color: #fff;
  background: var(--color-main-dark);
  border-radius: 999px;
  content: counter(flow);
  font-size: 13px;
  font-weight: 800;
}
.reading-flow strong, .reading-flow span { display: block; }
.reading-flow strong { color: var(--color-main-dark); font-size: 17px; }
.reading-flow span { margin-top: 6px; color: var(--color-muted); font-size: 14px; }
table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 12px;
  font-size: 15px;
}
th, td {
  padding: 10px;
  border: 1px solid var(--color-border);
  text-align: left;
  vertical-align: top;
}
th { color: #fff; background: var(--color-main-dark); }
.home-cta, .article-rich .cta-box {
  color: #fff;
  background: var(--color-main-dark);
  border-color: var(--color-main-dark);
}
.home-cta h2, .home-cta p, .article-rich .cta-box h2, .article-rich .cta-box p { color: #fff; }
.home-cta .button, .article-rich .cta-box .button {
  color: var(--color-main-dark);
  background: #fff;
  border-radius: 999px;
}
.breadcrumb {
  margin: 4px 0 18px;
  color: var(--color-muted);
  font-size: 14px;
}
.meta {
  margin: 10px 0 0;
  color: var(--color-muted);
  font-size: 14px;
}
.article-rich {
  background: linear-gradient(180deg, #eaf1f8 0, #f4f7fb 260px, #fff 260px);
}
.article-rich article, .article-rich .breadcrumb {
  max-width: 820px;
  margin-right: auto;
  margin-left: auto;
}
.article-rich h1 {
  margin-bottom: 16px;
  padding-bottom: 18px;
  border-bottom: 3px solid var(--color-accent);
  font-size: clamp(32px, 5vw, 48px);
}
.article-rich .lead {
  max-width: 780px;
  padding: 16px 18px;
  background: #fff;
  border: 1px solid var(--color-border);
  border-left: 6px solid var(--color-accent);
  font-size: 19px;
}
.article-rich .meta {
  margin-top: 14px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--color-border);
}
.intro-answer {
  margin-top: 30px;
  background: #fbfdff;
  border-left: 8px solid var(--color-main);
  box-shadow: 0 12px 30px rgba(47, 86, 135, 0.08);
}
.toc {
  margin-top: 28px;
  padding: 20px 22px;
  background: var(--color-soft);
  border: 1px solid var(--color-border);
  border-radius: 8px;
}
.toc ol {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px 20px;
  margin: 10px 0 0;
  padding-left: 22px;
}
.checklist, .warning-list, .question-box {
  margin-top: 20px;
  padding: 18px 20px;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  box-shadow: 0 8px 22px rgba(39, 49, 61, 0.05);
}
.warning-list { border-left: 6px solid var(--color-warning); }
.faq {
  margin-top: 44px;
  padding: 22px;
  background: #f8fbff;
  border: 1px solid var(--color-border);
  border-radius: 8px;
}
.faq h3 {
  margin-top: 18px;
  padding: 16px 0 0;
  border-top: 1px solid var(--color-border);
  color: var(--color-main-dark);
}
.site-footer {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  border-top: 1px solid var(--color-border);
  font-size: 14px;
}
@media (max-width: 760px) {
  .site-header { align-items: flex-start; flex-direction: column; margin-top: 0; border-radius: 0; }
  main, .home-rich main, .article-rich main { padding: 18px 14px 38px; border: 0; }
  .home-rich, .article-rich { background: #fff; }
  .home-hero { grid-template-columns: 1fr; padding: 18px; }
  .home-hero .label, .home-hero h1, .home-hero-text, .hero-visual { grid-column: 1; }
  .hero-visual { padding-top: 4px; }
  .hero-actions { flex-direction: column; }
  .hero-actions .button { width: 100%; text-align: center; }
  .summary-columns, .category-grid, .article-list, .related-grid, .reading-flow ol, .toc ol { grid-template-columns: 1fr; }
}

.article-hero-image {
  margin: 24px 0 28px;
}

.article-hero-image img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--color-border, #ddd);
  border-radius: 8px;
  object-fit: cover;
}