:root {
  --accent: #0f766e;
  --accent-light: #f0fdfa;
  --border: #d4d4d8;
  --text: #18181b;
  --muted: #71717a;
}
* { box-sizing: border-box; }
body {
  font-family: "Hiragino Sans", "Yu Gothic UI", "Meiryo", sans-serif;
  color: var(--text);
  max-width: 760px;
  margin: 0 auto;
  padding: 24px 16px 64px;
  line-height: 1.8;
}
a { color: var(--accent); }

.site-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 16px;
  margin-bottom: 24px;
}
.site-header .logo { font-size: 1.15rem; font-weight: 700; text-decoration: none; color: var(--text); }
.site-header nav a { margin-left: 16px; font-size: 0.9rem; text-decoration: none; }

.breadcrumb { font-size: 0.82rem; color: var(--muted); margin-bottom: 8px; }
.breadcrumb a { color: var(--muted); }

article h1 { font-size: 1.5rem; line-height: 1.5; margin: 0 0 8px; }
.article-meta { color: var(--muted); font-size: 0.82rem; margin-bottom: 24px; }
article h2 { font-size: 1.2rem; margin: 36px 0 12px; padding-top: 4px; border-top: 1px solid var(--border); padding-top: 16px; }
article h3 { font-size: 1.02rem; margin: 20px 0 8px; }
article p { margin: 0 0 16px; }
article ol, article ul { margin: 0 0 16px; padding-left: 1.4em; }
article li { margin-bottom: 6px; }
article table { border-collapse: collapse; width: 100%; margin: 12px 0 20px; font-size: 0.88rem; }
article th, article td { border: 1px solid var(--border); padding: 6px 10px; text-align: left; }
article th { background: #fafafa; }
code, .formula {
  font-family: "SFMono-Regular", Menlo, monospace;
  background: #f4f4f5;
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 6px;
  font-size: 0.88em;
}
.step-note {
  background: var(--accent-light);
  border: 1px solid var(--accent);
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 0.88rem;
  margin: 0 0 16px;
}

.cta-box {
  background: var(--accent-light);
  border: 2px solid var(--accent);
  border-radius: 12px;
  padding: 20px;
  margin: 32px 0;
}
.cta-box h2 { border-top: none; padding-top: 0; margin-top: 0; }
.cta-box p { margin-bottom: 12px; }
.cta-button {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  padding: 10px 22px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
}
.cta-button:hover { opacity: 0.9; }

.faq dt { font-weight: 700; margin-top: 14px; }
.faq dd { margin: 4px 0 0; color: var(--muted); font-size: 0.92rem; }

.blog-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 12px; }
.blog-list li { border: 1px solid var(--border); border-radius: 10px; padding: 14px 16px; }
.blog-list a { text-decoration: none; font-weight: 600; font-size: 1.02rem; }
.blog-list p { margin: 6px 0 0; color: var(--muted); font-size: 0.88rem; }

footer.site-footer { margin-top: 48px; color: var(--muted); font-size: 0.78rem; border-top: 1px solid var(--border); padding-top: 16px; }
footer.site-footer a { color: var(--muted); }