:root {
  --navy-950: #061329;
  --navy-900: #091a35;
  --navy-800: #10284b;
  --blue-600: #1e65f3;
  --blue-500: #3384ff;
  --cyan: #25d6c8;
  --ink: #0b1930;
  --muted: #5e6a7d;
  --line: #dce3ec;
  --wash: #f3f7fb;
  --white: #fff;
  --article-width: 760px;
}

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

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--white);
  font-family: "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
  font-size: 17px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--blue-600);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
}

.site-header {
  border-bottom: 1px solid var(--line);
  background: var(--white);
}

.header-inner {
  width: min(calc(100% - 40px), var(--article-width));
  margin: 0 auto;
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  color: var(--navy-950);
  font-weight: 800;
  font-size: 22px;
  letter-spacing: 0.12em;
  text-decoration: none;
}

.brand:hover {
  text-decoration: none;
}

.brand-mark {
  width: 27px;
  height: 27px;
  display: grid;
  grid: auto / repeat(3, 1fr);
  align-items: end;
  gap: 3px;
  transform: skew(-12deg);
}

.brand-mark span {
  display: block;
  background: var(--cyan);
  border-radius: 1px;
}

.brand-mark span:nth-child(1) {
  height: 11px;
}

.brand-mark span:nth-child(2) {
  height: 19px;
}

.brand-mark span:nth-child(3) {
  height: 27px;
  background: var(--blue-500);
}

.header-label {
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.18em;
}

.header-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 18px;
  align-items: center;
}

.header-nav a {
  color: var(--navy-900);
  font-size: 13px;
  font-weight: 700;
  text-decoration: none;
}

.header-nav a:hover {
  color: var(--blue-600);
  text-decoration: none;
}

.breadcrumbs {
  margin: 0 0 18px;
}

.breadcrumbs ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 0;
  color: var(--muted);
  font-size: 13px;
}

.breadcrumbs li:not(:last-child)::after {
  content: "›";
  margin: 0 8px;
  color: #9aa7bb;
}

.breadcrumbs a {
  color: var(--muted);
  font-weight: 600;
}

.toc {
  margin: 0 0 28px;
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--wash);
}

.toc-title {
  margin: 0 0 10px;
  color: var(--navy-900);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.toc ol {
  margin: 0;
  padding-left: 1.2em;
}

.toc li {
  margin: 0.35em 0;
  font-size: 14px;
}

.related-articles,
.service-cta {
  margin: 40px 0 0;
  padding: 24px 0 0;
  border-top: 1px solid var(--line);
}

.related-articles h2,
.service-cta h2 {
  margin: 0 0 12px;
  color: var(--navy-950);
  font-size: 1.15rem;
  font-weight: 800;
}

.related-articles ul,
.service-cta ul {
  margin: 0 0 16px;
  padding-left: 1.2em;
}

.cta-actions {
  margin: 0;
}

.cta-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 22px;
  border-radius: 8px;
  background: var(--blue-600);
  color: var(--white) !important;
  font-weight: 800;
  font-size: 15px;
  text-decoration: none !important;
}

.cta-button:hover {
  background: #1854d1;
}

.article-pager {
  margin: 36px 0 0;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px 20px;
  font-size: 14px;
  font-weight: 700;
}

.article-shell {
  width: min(calc(100% - 40px), var(--article-width));
  margin: 0 auto;
  padding: 40px 0 72px;
}

.article-meta {
  margin: 0 0 20px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.article-body h1 {
  margin: 0 0 16px;
  color: var(--navy-950);
  font-size: clamp(1.75rem, 4vw, 2.15rem);
  line-height: 1.45;
  letter-spacing: 0.02em;
  font-weight: 800;
}

.article-body h2 {
  margin: 2.6em 0 0.85em;
  padding-bottom: 0.35em;
  color: var(--navy-900);
  font-size: clamp(1.25rem, 2.8vw, 1.45rem);
  line-height: 1.5;
  border-bottom: 2px solid var(--line);
  font-weight: 800;
}

.article-body h2:first-of-type {
  margin-top: 0.6em;
}

.article-body h3 {
  margin: 2em 0 0.7em;
  color: var(--navy-800);
  font-size: 1.08rem;
  line-height: 1.55;
  font-weight: 700;
}

.article-body p {
  margin: 0 0 1.25em;
  color: var(--ink);
}

.article-body ul,
.article-body ol {
  margin: 0 0 1.4em;
  padding-left: 1.4em;
}

.article-body li {
  margin: 0.35em 0;
}

.article-body li + li {
  margin-top: 0.45em;
}

.article-body strong {
  color: var(--navy-950);
  font-weight: 700;
}

.article-body hr {
  margin: 2.4em 0;
  border: 0;
  border-top: 1px solid var(--line);
}

.article-body .table-wrap {
  width: 100%;
  overflow-x: auto;
  margin: 0 0 1.6em;
  -webkit-overflow-scrolling: touch;
}

.article-body table {
  width: 100%;
  min-width: 320px;
  border-collapse: collapse;
  font-size: 0.95rem;
}

.article-body th,
.article-body td {
  padding: 12px 14px;
  border: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.article-body th {
  background: var(--wash);
  color: var(--navy-900);
  font-weight: 700;
}

.article-body td {
  background: var(--white);
}

.site-footer {
  border-top: 1px solid var(--line);
  background: var(--wash);
}

.footer-inner {
  width: min(calc(100% - 40px), var(--article-width));
  margin: 0 auto;
  padding: 36px 0 48px;
}

.footer-nav {
  margin: 0 0 18px;
  display: flex;
  flex-wrap: wrap;
  gap: 16px 28px;
}

.footer-nav a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--navy-900);
  font-weight: 700;
  font-size: 15px;
}

.footer-nav a:hover {
  color: var(--blue-600);
}

.footer-copy {
  margin: 0;
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.02em;
}

.article-nav {
  margin: 0 0 24px;
  font-size: 14px;
  font-weight: 600;
}

.list-title {
  margin: 0 0 12px;
  color: var(--navy-950);
  font-size: clamp(1.75rem, 4vw, 2.15rem);
  line-height: 1.45;
  letter-spacing: 0.02em;
  font-weight: 800;
}

.list-lead {
  margin: 0 0 36px;
  color: var(--muted);
  font-size: 15px;
}

.article-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.article-card {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--white);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.article-card:hover {
  border-color: #b8c7dc;
  box-shadow: 0 8px 24px rgba(9, 26, 53, 0.06);
}

.article-card-link {
  display: block;
  padding: 22px 22px 24px;
  color: inherit;
  text-decoration: none;
}

.article-card-link:hover {
  text-decoration: none;
}

.article-card-meta {
  display: block;
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.article-card-title {
  display: block;
  margin: 0 0 10px;
  color: var(--navy-950);
  font-size: 1.12rem;
  font-weight: 800;
  line-height: 1.55;
}

.article-card-desc {
  display: block;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

@media (max-width: 640px) {
  body {
    font-size: 16px;
  }

  .header-inner {
    min-height: 64px;
  }

  .brand {
    font-size: 18px;
    letter-spacing: 0.1em;
  }

  .article-shell {
    padding: 28px 0 56px;
  }

  .article-body h2 {
    margin-top: 2.2em;
  }

  .article-body th,
  .article-body td {
    padding: 10px 12px;
  }

  .article-card-link {
    padding: 18px 16px 20px;
  }
}