:root {
  --c-bg: #fafafa;
  --c-surface: #ffffff;
  --c-text: #1a1a1a;
  --c-muted: #666;
  --c-border: #e5e5e5;
  --c-accent: #2a6acc;
  --c-accent-dark: #1f4d99;
  --c-accent-light: #e3f2fd;
  --c-good-bg: #e8f5e9;
  --c-good-border: #a5d6a7;
  --c-warn-bg: #fff8e1;
  --c-warn-border: #ffd54f;
  --c-info-bg: #e3f2fd;
  --c-info-border: #90caf9;
  --c-code-bg: #f6f8fa;
  --max-width: 920px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans", "Noto Sans JP", system-ui, sans-serif;
  line-height: 1.85;
  color: var(--c-text);
  margin: 0;
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
}
/* Site-wide nav (shared with main site pages) */
.site-header {
  position: sticky; top: 0;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--c-border);
  z-index: 100;
}
.site-nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.7rem 1.2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.site-nav .logo {
  display: inline-flex;
  align-items: center;
  color: var(--c-text);
  line-height: 0;
}
.site-nav .logo img { height: 32px; width: auto; display: block; }
.site-nav ul {
  display: flex;
  gap: 1.4rem;
  list-style: none;
  margin: 0; padding: 0;
  font-size: 0.92rem;
}
.site-nav ul a {
  color: var(--c-text);
  font-weight: 500;
  padding: 0.2rem 0;
  border-bottom: 2px solid transparent;
  text-decoration: none;
  transition: border-color 0.15s, color 0.15s;
}
.site-nav ul a:hover { color: var(--c-accent); text-decoration: none; }
.site-nav ul a.active {
  color: var(--c-accent);
  border-bottom-color: var(--c-accent);
}
@media (max-width: 700px) {
  .site-nav ul { gap: 0.8rem; font-size: 0.82rem; flex-wrap: wrap; justify-content: flex-end; }
  .site-nav .logo img { height: 26px; }
}

/* Legacy nav.top alias (kept for older articles before nav refresh) */
nav.top { display: none; }
article.post {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2.5rem 1.6rem 4rem;
}
/* 本文の文字列は読みやすさを保つため、コード/テーブルは横幅いっぱい使うが、
   段落テキストは最大幅を制限して目線移動の幅を抑える */
.post-body p,
.post-body ul,
.post-body ol,
.post-body blockquote,
.post-glossary {
  max-width: 760px;
}
.post-body pre,
.post-body table,
.post-body .ascii,
.post-body .callout {
  max-width: 100%;
}
.post-header { margin-bottom: 2rem; padding-bottom: 1rem; border-bottom: 1px solid var(--c-border); }
.post-meta {
  color: var(--c-muted);
  font-size: 0.85rem;
  margin: 0 0 0.5rem;
  letter-spacing: 0.05em;
}
.post-header h1 {
  font-size: clamp(1.5rem, 3.5vw, 2rem);
  margin: 0;
  line-height: 1.4;
}
.post-body h2 {
  font-size: 1.35rem;
  margin: 2.5rem 0 0.8rem;
  padding-bottom: 0.3rem;
  border-bottom: 2px solid var(--c-border);
}
.post-body h3 { font-size: 1.1rem; margin: 1.8rem 0 0.6rem; }
.post-body p { margin: 0.8rem 0; }
.post-body a { color: var(--c-accent); }
.post-body code {
  background: var(--c-code-bg);
  padding: 1px 6px;
  border-radius: 3px;
  font-size: 0.88em;
  font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
}
.post-body pre {
  background: var(--c-code-bg);
  border: 1px solid var(--c-border);
  border-radius: 5px;
  padding: 0.9rem 1rem;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.55;
  margin: 1rem 0;
}
.post-body pre code { background: transparent; padding: 0; font-size: 1em; }
.post-body table {
  border-collapse: collapse;
  width: 100%;
  margin: 1rem 0;
  font-size: 0.92rem;
}
.post-body th, .post-body td {
  border: 1px solid var(--c-border);
  padding: 0.5rem 0.7rem;
  text-align: left;
  vertical-align: top;
}
.post-body th { background: #f3f3f3; font-weight: 600; }
.post-body ul, .post-body ol { padding-left: 1.4rem; }
.post-body li { margin: 0.3rem 0; }
.callout {
  padding: 0.7rem 1rem;
  margin: 1rem 0;
  border-radius: 5px;
  border-left: 4px solid;
}
.callout.warn { background: var(--c-warn-bg); border-color: var(--c-warn-border); }
.callout.info { background: var(--c-info-bg); border-color: var(--c-info-border); }
.callout.good { background: var(--c-good-bg); border-color: var(--c-good-border); }
.post-glossary {
  margin-top: 3rem;
  padding: 1.5rem 1.7rem;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: 8px;
}
.post-glossary h2 { font-size: 1.15rem; margin: 0 0 1rem; }
.post-glossary dl { margin: 0; }
.post-glossary dt {
  font-weight: 700;
  color: var(--c-accent);
  margin-top: 0.8rem;
}
.post-glossary dd {
  margin: 0.2rem 0 0 1.4rem;
  color: var(--c-text);
  font-size: 0.95rem;
}
.post-footer {
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid var(--c-border);
  display: flex;
  justify-content: space-between;
  font-size: 0.92rem;
}
.post-footer a { color: var(--c-accent); text-decoration: none; }
.post-footer a:hover { text-decoration: underline; }

/* Blog index page */
.blog-index { max-width: var(--max-width); margin: 0 auto; padding: 2.5rem 1.2rem 4rem; }
.blog-index h1 { font-size: 1.7rem; margin: 0 0 0.5rem; }
.blog-index .lead { color: var(--c-muted); margin: 0 0 2rem; }
.post-list-index { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.6rem; }
.post-list-index li {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: 6px;
  padding: 1rem 1.2rem;
  transition: border-color 0.2s;
}
.post-list-index li:hover { border-color: var(--c-accent); }
.post-list-index a { color: var(--c-text); text-decoration: none; font-weight: 600; }
.post-list-index a:hover { color: var(--c-accent); }
.post-list-index .post-num {
  display: inline-block;
  background: var(--c-accent-light);
  color: var(--c-accent-dark);
  font-size: 0.78rem;
  padding: 1px 6px;
  border-radius: 3px;
  margin-right: 0.5rem;
  font-weight: 600;
}
.post-list-index .post-summary {
  display: block;
  color: var(--c-muted);
  font-size: 0.88rem;
  margin-top: 0.3rem;
}