:root {
  --c-bg: #eef3fa;
  --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;
}
body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    radial-gradient(1200px 600px at 80% -10%, rgba(42, 106, 204, 0.18), transparent 60%),
    radial-gradient(900px 500px at -10% 110%, rgba(10, 163, 163, 0.08), transparent 60%);
  z-index: -1;
}
/* 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;
  position: relative;
}
/* 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; position: relative; }
article.post::before, .blog-index::before {
  content: '';
  position: absolute;
  top: 0;
  left: calc(-50vw + 50%);
  right: calc(-50vw + 50%);
  height: 170px;
  background:
    linear-gradient(to bottom, rgba(0, 0, 0, 0) 55%, var(--c-bg) 100%),
    linear-gradient(135deg,
      rgba(42, 106, 204, 0.22) 0%,
      rgba(10, 163, 163, 0.18) 60%,
      transparent 100%);
  z-index: -1;
  pointer-events: none;
}
.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;
}

/* ── Dark mode (matches site.css palette) ─────────────────── */
@media (prefers-color-scheme: dark) {
  :root {
    --c-bg: #0e1117;
    --c-surface: #161d27;
    --c-text: #e7ecf2;
    --c-muted: #8995a4;
    --c-border: #232c39;
    --c-accent: #4d8cf0;
    --c-accent-dark: #3a72d0;
    --c-accent-light: #1b2b48;
    --c-good-bg: #102816;
    --c-good-border: #5fc76e;
    --c-warn-bg: #2a210d;
    --c-warn-border: #ffd54f;
    --c-info-bg: #1b2b48;
    --c-info-border: #4d8cf0;
    --c-code-bg: #131a23;
  }
  body::before {
    background-image:
      radial-gradient(1200px 600px at 80% -10%, rgba(77, 140, 240, 0.30), transparent 60%),
      radial-gradient(900px 500px at -10% 110%, rgba(45, 212, 207, 0.10), transparent 60%);
  }
  .site-header { background: rgba(19, 26, 35, 0.85); }
  .post-body th { background: #1c2532; }
}

/* ── Responsive: tablet ─────────────────────── */
@media (max-width: 720px) {
  article.post {
    padding: 1.8rem 1rem 3rem;
  }
  .blog-index {
    padding: 1.8rem 1rem 3rem;
  }
  .post-body h2 { font-size: 1.2rem; margin: 2rem 0 0.7rem; }
  .post-body h3 { font-size: 1.05rem; margin: 1.4rem 0 0.5rem; }
  .post-body pre {
    padding: 0.7rem 0.8rem;
    font-size: 0.8rem;
  }
  /* Tables overflow horizontally on narrow screens — scroll instead of breaking layout */
  .post-body table {
    display: block;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    font-size: 0.85rem;
    white-space: nowrap;
  }
  .post-body th, .post-body td { padding: 0.4rem 0.55rem; }
  .post-glossary {
    padding: 1.1rem 1.1rem;
    margin-top: 2rem;
  }
  .post-list-index li {
    padding: 0.85rem 1rem;
  }
}

/* ── Responsive: phone ──────────────────────── */
@media (max-width: 480px) {
  body { line-height: 1.75; font-size: 15px; }
  article.post {
    padding: 1.4rem 0.85rem 2.5rem;
  }
  .blog-index {
    padding: 1.4rem 0.85rem 2.5rem;
  }
  .post-body pre {
    font-size: 0.75rem;
    padding: 0.6rem 0.7rem;
  }
  .post-body code { word-break: break-word; }
  .post-body table { font-size: 0.8rem; }
  .post-footer {
    flex-direction: column;
    gap: 0.6rem;
    align-items: flex-start;
  }
  .blog-index h1 { font-size: 1.4rem; }
}