*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg: #fafbfc; --surface: #ffffff; --border: #e4e7ec; --border-strong: #d0d5dd;
  --accent: #2563eb; --accent-dim: rgba(37,99,235,0.08); --accent-ink: #1d4ed8;
  --text: #0f172a; --muted: #64748b; --body: #334155; --code-bg: #f1f5f9;
  --sans: 'Inter', ui-sans-serif, -apple-system, "Helvetica Neue", Arial, sans-serif;
  --mono: 'JetBrains Mono', ui-monospace, "SF Mono", Menlo, monospace;
}
:root[data-theme="dark"] {
  --bg: #0b1120; --surface: #131b2e; --border: #1f2937; --border-strong: #334155;
  --accent: #3b82f6; --accent-dim: rgba(59,130,246,0.15); --accent-ink: #60a5fa;
  --text: #f1f5f9; --muted: #94a3b8; --body: #cbd5e1; --code-bg: #0f1729;
}
html { scroll-behavior: smooth; }
body { background: var(--bg); color: var(--text); font-family: var(--sans); min-height: 100vh; overflow-x: hidden; -webkit-font-smoothing: antialiased; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
a { color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.wrapper { max-width: 1180px; margin: 0 auto; padding: 0 24px; }
header { padding: 32px 0 0; display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 16px; }
.logo { font-weight: 800; font-size: 1.65rem; letter-spacing: -0.01em; color: var(--text); text-decoration: none; }
.logo span { color: var(--accent); }
.header-links { display: flex; gap: 24px; align-items: center; }
.header-links a { color: var(--muted); text-decoration: none; font-size: 0.875rem; font-weight: 500; transition: color 0.2s; }
.header-links a:hover, .header-links a[aria-current] { color: var(--text); }
.theme-toggle { display: inline-flex; align-items: center; justify-content: center; width: 30px; height: 30px; border-radius: 8px; border: 1px solid var(--border); background: var(--surface); color: var(--muted); cursor: pointer; transition: color 0.2s, border-color 0.2s; }
.theme-toggle:hover { color: var(--text); border-color: var(--border-strong); }
.theme-toggle .icon-sun { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-sun { display: inline-block; }
:root[data-theme="dark"] .theme-toggle .icon-moon { display: none; }
footer { border-top: 1px solid var(--border); padding: 32px 0; display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 12px; margin-top: 48px; }
.footer-copy { font-size: 0.82rem; color: var(--muted); }
.footer-copy a { text-decoration: none; }
.footer-copy a:hover { color: var(--accent-ink); }

.article { max-width: 760px; margin: 0 auto; padding: 56px 0 0; }
.breadcrumb { font-family: var(--mono); font-size: .8rem; color: var(--muted); text-decoration: none; display: inline-block; margin-bottom: 28px; }
.breadcrumb:hover { color: var(--accent-ink); }
.kicker { font-family: var(--mono); font-size: .75rem; letter-spacing: .05em; text-transform: uppercase; color: var(--accent-ink); margin-bottom: 14px; }
.article h1 { font-weight: 800; font-size: clamp(1.8rem, 4vw, 2.5rem); line-height: 1.2; letter-spacing: -.025em; margin-bottom: 18px; }
.article-meta { display: flex; flex-wrap: wrap; gap: .6rem; font-family: var(--mono); font-size: .78rem; color: var(--muted); padding-bottom: 28px; border-bottom: 1px solid var(--border); }
.lede { color: var(--muted); font-size: 1rem; line-height: 1.7; margin-bottom: 40px; max-width: 62ch; }
.lede a { color: var(--accent-ink); }

.article-body { padding-top: 32px; font-size: 1.05rem; line-height: 1.75; color: var(--body); }
.article-body p { margin-bottom: 1.35rem; }
.article-body h2 { font-weight: 800; font-size: 1.45rem; color: var(--text); letter-spacing: -.015em; margin: 2.4rem 0 1rem; line-height: 1.3; }
.article-body h3 { font-weight: 700; font-size: 1.15rem; color: var(--text); margin: 2rem 0 .9rem; line-height: 1.35; }
.article-body h4 { font-weight: 700; font-size: 1.02rem; color: var(--text); margin: 1.6rem 0 .7rem; }
.article-body ul, .article-body ol { margin: 0 0 1.4rem 1.3rem; }
.article-body li { margin-bottom: .5rem; }
.article-body strong { color: var(--text); font-weight: 700; }
.article-body a { color: var(--accent-ink); text-decoration: none; border-bottom: 1px solid var(--accent-dim); word-break: break-word; }
.article-body a:hover { border-color: var(--accent); }
.article-body figure { margin: 1.8rem 0; }
.article-body img { display: block; max-width: 100%; height: auto; border-radius: 10px; border: 1px solid var(--border); }
.article-body figcaption { margin-top: .6rem; font-size: .82rem; color: var(--muted); text-align: center; }
.article-body blockquote { margin: 1.8rem 0; padding: 1rem 1.4rem; border-left: 3px solid var(--accent); background: var(--surface); border-radius: 0 8px 8px 0; font-style: italic; }
.article-body code { font-family: var(--mono); font-size: .84em; background: var(--code-bg); padding: .15em .4em; border-radius: 4px; overflow-wrap: anywhere; }
.article-body pre { margin: 1.6rem 0; padding: 1.1rem 1.3rem; background: var(--code-bg); border: 1px solid var(--border); border-radius: 10px; overflow-x: auto; font-size: .84rem; line-height: 1.6; }
.article-body pre code { background: none; padding: 0; white-space: pre; overflow-wrap: normal; }
.article-body table { width: 100%; border-collapse: collapse; margin: 1.6rem 0; font-size: .92rem; display: block; overflow-x: auto; }
.article-body th, .article-body td { border: 1px solid var(--border); padding: .55rem .8rem; text-align: left; }
.article-body th { background: var(--surface); color: var(--text); }
.article-body hr { border: 0; border-top: 1px solid var(--border); margin: 2rem 0; }
.article-source-note { margin-top: 2rem; padding-top: 1.5rem; border-top: 1px solid var(--border); font-size: .88rem; color: var(--muted); }

.section-label { font-size: .78rem; font-weight: 600; letter-spacing: .02em; color: var(--muted); margin: 40px 0 8px; display: flex; align-items: center; gap: 12px; text-transform: uppercase; }
.section-label::after { content: ''; flex: 1; height: 1px; background: var(--border); }
.section-label .count { font-family: var(--mono); font-weight: 500; color: var(--accent-ink); }
.post-row { display: grid; grid-template-columns: 1fr auto; gap: 4px 20px; padding: 16px 0; border-bottom: 1px solid var(--border); text-decoration: none; }
.post-row:hover .post-row-title { color: var(--accent-ink); }
.post-row-title { font-weight: 600; font-size: 1.02rem; color: var(--text); letter-spacing: -.01em; transition: color .2s; }
.post-row-desc { grid-column: 1; font-size: .88rem; color: var(--muted); line-height: 1.55; }
.post-row-date { grid-column: 2; grid-row: 1; font-family: var(--mono); font-size: .74rem; color: var(--muted); white-space: nowrap; align-self: start; padding-top: 3px; }
@media (max-width: 560px) { .post-row { grid-template-columns: 1fr; } .post-row-date { grid-column: 1; grid-row: auto; } }

/* ── Listing v2: sidebar + cards ── */
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.blog-shell { padding-top: 56px; }
.blog-hero { max-width: 760px; }
.blog-layout { display: grid; grid-template-columns: 250px minmax(0, 1fr); gap: 48px; align-items: start; margin-top: 8px; }
.blog-side { position: sticky; top: 24px; max-height: calc(100vh - 48px); overflow-y: auto; padding-right: 6px; scrollbar-width: thin; }
.search { display: flex; align-items: center; gap: 8px; padding: 0 12px; height: 38px; background: var(--surface); border: 1px solid var(--border); border-radius: 10px; color: var(--muted); transition: border-color .2s; }
.search:focus-within { border-color: var(--accent); }
.search input { flex: 1; min-width: 0; background: none; border: 0; outline: 0; font: inherit; font-size: .88rem; color: var(--text); }
.side-label { font-family: var(--mono); font-size: .68rem; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); margin: 26px 0 8px; }
.f-tree { display: flex; flex-direction: column; gap: 2px; }
.f-btn { display: flex; align-items: center; justify-content: space-between; gap: 8px; width: 100%; text-align: left; background: none; border: 0; border-radius: 8px; padding: 7px 10px; font: inherit; font-size: .86rem; color: var(--body); cursor: pointer; transition: background .15s, color .15s; }
.f-btn b { font-family: var(--mono); font-weight: 500; font-size: .7rem; color: var(--muted); }
.f-btn:hover { background: var(--accent-dim); color: var(--text); }
.f-btn.is-active { background: var(--accent-dim); color: var(--accent-ink); font-weight: 600; }
.f-btn.is-active b { color: var(--accent-ink); }
.f-sub { padding-left: 22px; font-size: .83rem; color: var(--muted); }
.f-group summary { display: flex; align-items: center; justify-content: space-between; gap: 8px; list-style: none; cursor: pointer; padding: 8px 10px; border-radius: 8px; font-size: .84rem; font-weight: 600; color: var(--text); }
.f-group summary::-webkit-details-marker { display: none; }
.f-group summary::before { content: ''; width: 6px; height: 6px; border-right: 1.5px solid var(--muted); border-bottom: 1.5px solid var(--muted); transform: rotate(-45deg); transition: transform .2s; margin-right: 2px; flex: none; }
.f-group[open] > summary::before { transform: rotate(45deg); }
.f-group summary span { flex: 1; }
.f-group summary b { font-family: var(--mono); font-weight: 500; font-size: .7rem; color: var(--muted); }
.f-group summary:hover { background: var(--accent-dim); }
.side-note { margin-top: 24px; font-size: .82rem; }
.side-note a { color: var(--muted); text-decoration: none; }
.side-note a:hover { color: var(--accent-ink); }
.post-cards { display: flex; flex-direction: column; gap: 14px; }
.post-card { display: block; padding: 20px 22px; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; text-decoration: none; transition: border-color .2s, box-shadow .2s, transform .2s; }
.post-card[hidden] { display: none; }
.post-card:hover { border-color: var(--accent); box-shadow: 0 8px 24px -10px rgba(37,99,235,.35); transform: translateY(-2px); }
.post-card-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 12px; font-family: var(--mono); font-size: .72rem; color: var(--muted); margin-bottom: 10px; }
.chip { color: var(--accent-ink); background: var(--accent-dim); border-radius: 999px; padding: 2px 10px; font-weight: 500; }
.post-card h2 { font-size: 1.15rem; font-weight: 700; letter-spacing: -.015em; color: var(--text); line-height: 1.35; margin-bottom: 6px; }
.post-card p { font-size: .9rem; line-height: 1.6; color: var(--muted); }
.empty { color: var(--muted); padding: 32px 0; text-align: center; }
@media (max-width: 860px) {
  .blog-layout { grid-template-columns: 1fr; gap: 24px; }
  .blog-side { position: static; max-height: none; overflow: visible; padding: 0; }
}

/* ── End-of-post: keep reading ── */
.more { margin-top: 56px; padding-top: 36px; border-top: 1px solid var(--border); }
.more h2 { font-size: 1.25rem; font-weight: 800; letter-spacing: -.015em; margin-bottom: 18px; }
.more-cards { display: flex; flex-direction: column; gap: 12px; }
.more .post-card { padding: 16px 20px; }
.more .post-card h3 { font-size: 1.02rem; font-weight: 700; letter-spacing: -.01em; color: var(--text); line-height: 1.35; margin-bottom: 4px; }
.more .post-card p { font-size: .86rem; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.more-links { display: flex; flex-wrap: wrap; gap: 10px; margin: 20px 0 0; }
.more-btn { display: inline-flex; align-items: center; padding: 9px 16px; border: 1px solid var(--border-strong); border-radius: 999px; font-size: .86rem; font-weight: 600; color: var(--text); text-decoration: none; transition: border-color .2s, color .2s, background .2s; }
.more-btn:hover { border-color: var(--accent); color: var(--accent-ink); background: var(--accent-dim); }
.follow { margin-top: 32px; padding: 20px 22px; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; }
.follow p { font-size: .92rem; color: var(--body); }
.follow-links { display: flex; flex-wrap: wrap; gap: 8px 18px; margin-top: 10px; font-family: var(--mono); font-size: .8rem; }
.follow-links a { color: var(--accent-ink); text-decoration: none; }
.follow-links a:hover { text-decoration: underline; }

.side-filters > summary { list-style: none; cursor: pointer; display: none; align-items: center; justify-content: space-between; margin-top: 12px; padding: 10px 14px; border: 1px solid var(--border); border-radius: 10px; background: var(--surface); font-size: .88rem; font-weight: 600; color: var(--text); }
.side-filters > summary::-webkit-details-marker { display: none; }
.side-filters > summary::after { content: '+'; font-family: var(--mono); color: var(--muted); }
.side-filters[open] > summary::after { content: '\2212'; }
@media (max-width: 860px) { .side-filters > summary { display: flex; } }