*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    :root {
      --bg: #0F172A; --surface: #1E293B; --surface2: #162032;
      --amber: #F59E0B; --amber-glow: rgba(245,158,11,0.15); --amber-glow2: rgba(245,158,11,0.07);
      --emerald: #10B981; --cyan: #22D3EE; --rose: #F43F5E;
      --white: #F8FAFC; --muted: #94A3B8; --muted-dim: #8A97A8; --border: rgba(245,158,11,0.18);
      --code-bg: #0d1117;
    }
    html { scroll-behavior: smooth; }
    body { background: var(--bg); color: var(--white); font-family: 'DM Sans', sans-serif; font-size: 17px; line-height: 1.85; overflow-x: hidden; }

    /* READING PROGRESS BAR */
    #progress-bar { position: fixed; top: 0; left: 0; height: 3px; width: 0%; background: linear-gradient(90deg, var(--amber), var(--emerald)); z-index: 200; transition: width 0.1s linear; }

    /* NAV */
    nav { position: fixed; top: 3px; left: 0; right: 0; z-index: 100; display: flex; justify-content: space-between; align-items: center; padding: 1.1rem 5%; background: rgba(15,23,42,0.92); backdrop-filter: blur(18px); border-bottom: 1px solid var(--border); }
    .nav-logo { font-family: 'Syne', sans-serif; font-weight: 800; font-size: 0.95rem; color: var(--white); text-decoration: none; }
    .nav-logo span { color: var(--amber); }
    .nav-links { display: flex; align-items: center; gap: 1.5rem; }
    .nav-links a { font-family: 'DM Mono', monospace; font-size: 0.72rem; color: var(--muted); text-decoration: none; text-transform: uppercase; letter-spacing: 0.08em; transition: color 0.2s; }
    .nav-links a:hover { color: var(--amber); }

    /* LAYOUT */
    .page-wrap { max-width: 1100px; margin: 0 auto; padding: 8rem 5% 5rem; display: grid; grid-template-columns: 1fr 220px; gap: 4rem; align-items: start; }
    @media (max-width: 900px) { .page-wrap { grid-template-columns: 1fr; } .toc-aside { display: none; } }

    /* TOC */
    .toc-aside { position: sticky; top: 8rem; }
    .toc-label { font-family: 'DM Mono', monospace; font-size: 0.65rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--amber); margin-bottom: 0.8rem; }
    .toc-list { list-style: none; display: flex; flex-direction: column; gap: 0.2rem; }
    .toc-list a { font-family: 'DM Mono', monospace; font-size: 0.72rem; color: var(--muted); text-decoration: none; display: block; padding: 0.3rem 0.5rem; border-left: 2px solid transparent; transition: all 0.2s; border-radius: 0 4px 4px 0; }
    .toc-list a:hover, .toc-list a.active { color: var(--amber); border-left-color: var(--amber); background: var(--amber-glow2); }
    .toc-list a.h3 { padding-left: 1.2rem; font-size: 0.67rem; }

    /* ARTICLE */
    article { min-width: 0; }
    .post-meta-bar { display: flex; align-items: center; gap: 0.8rem; flex-wrap: wrap; margin-bottom: 2rem; }
    .cat-tag { font-family: 'DM Mono', monospace; font-size: 0.62rem; letter-spacing: 0.1em; text-transform: uppercase; padding: 0.2rem 0.6rem; border-radius: 4px; background: rgba(16,185,129,0.1); color: var(--emerald); border: 1px solid rgba(16,185,129,0.25); }
    .depth-tag { font-family: 'DM Mono', monospace; font-size: 0.62rem; letter-spacing: 0.08em; text-transform: uppercase; padding: 0.2rem 0.6rem; border-radius: 4px; background: rgba(245,158,11,0.07); color: var(--amber); border: 1px solid rgba(245,158,11,0.2); }
    .meta-info { font-family: 'DM Mono', monospace; font-size: 0.68rem; color: var(--muted); }
    h1.post-title { font-family: 'Syne', sans-serif; font-weight: 800; font-size: clamp(1.8rem, 4vw, 2.8rem); line-height: 1.15; letter-spacing: -0.02em; margin-bottom: 1rem; }
    .post-lead { font-size: 1.05rem; color: var(--muted); line-height: 1.7; border-left: 3px solid var(--amber); padding-left: 1.2rem; margin-bottom: 3rem; }

    /* PROSE */
    .prose h2 { font-family: 'Syne', sans-serif; font-size: 1.35rem; font-weight: 700; margin: 2.5rem 0 0.8rem; padding-top: 2rem; border-top: 1px solid rgba(255,255,255,0.06); color: var(--white); scroll-margin-top: 6rem; }
    .prose h3 { font-family: 'Syne', sans-serif; font-size: 1.05rem; font-weight: 700; margin: 1.8rem 0 0.6rem; color: var(--white); scroll-margin-top: 6rem; }
    .prose p { color: var(--muted); margin-bottom: 1.2rem; }
    .prose strong { color: var(--white); }
    .prose em { color: var(--amber); font-style: normal; }
    .prose a { color: var(--cyan); text-decoration: underline; text-underline-offset: 3px; }
    .prose ul { list-style: none; margin: 1rem 0 1.4rem; display: flex; flex-direction: column; gap: 0.5rem; }
    .prose ul li { color: var(--muted); padding-left: 1.4rem; position: relative; }
    .prose ul li::before { content: '▸'; position: absolute; left: 0; color: var(--amber); }
    .prose ol { list-style: none; counter-reset: list; margin: 1rem 0 1.4rem; display: flex; flex-direction: column; gap: 0.5rem; }
    .prose ol li { color: var(--muted); padding-left: 2rem; position: relative; counter-increment: list; }
    .prose ol li::before { content: counter(list) '.'; position: absolute; left: 0; color: var(--amber); font-family: 'DM Mono', monospace; font-size: 0.8rem; }

    /* CODE */
    .prose pre { background: var(--code-bg); border: 1px solid rgba(255,255,255,0.08); border-radius: 10px; padding: 1.4rem; overflow-x: auto; margin: 1.5rem 0; position: relative; }
    .prose pre::before { content: attr(data-lang); position: absolute; top: 0.6rem; right: 0.9rem; font-family: 'DM Mono', monospace; font-size: 0.6rem; color: #4a5568; letter-spacing: 0.08em; text-transform: uppercase; }
    .prose code { font-family: 'DM Mono', monospace; font-size: 0.88rem; line-height: 1.8; color: #e2e8f0; }
    .prose p code, .prose li code { background: rgba(255,255,255,0.06); padding: 0.15em 0.45em; border-radius: 4px; font-size: 0.83rem; color: var(--cyan); }

    /* CALLOUTS */
    .callout { padding: 1.2rem 1.5rem; border-radius: 10px; margin: 1.5rem 0; }
    .callout-warn { background: rgba(245,158,11,0.07); border: 1px solid rgba(245,158,11,0.2); border-left: 3px solid var(--amber); }
    .callout-good { background: rgba(16,185,129,0.07); border: 1px solid rgba(16,185,129,0.2); border-left: 3px solid var(--emerald); }
    .callout-bad { background: rgba(244,63,94,0.07); border: 1px solid rgba(244,63,94,0.2); border-left: 3px solid var(--rose); }
    .callout p { margin-bottom: 0 !important; font-size: 0.92rem; }
    .callout strong { font-family: 'DM Mono', monospace; font-size: 0.7rem; letter-spacing: 0.08em; text-transform: uppercase; display: block; margin-bottom: 0.5rem; }
    .callout-warn strong { color: var(--amber); }
    .callout-good strong { color: var(--emerald); }
    .callout-bad strong { color: var(--rose); }

    /* COMPARISON TABLE */
    .compare-table { width: 100%; border-collapse: collapse; margin: 1.5rem 0; font-size: 0.88rem; }
    .compare-table th { font-family: 'DM Mono', monospace; font-size: 0.7rem; letter-spacing: 0.08em; text-transform: uppercase; color: var(--muted); text-align: left; padding: 0.6rem 0.8rem; border-bottom: 1px solid rgba(255,255,255,0.08); }
    .compare-table td { padding: 0.7rem 0.8rem; border-bottom: 1px solid rgba(255,255,255,0.04); color: var(--muted); vertical-align: top; }
    .compare-table .win { color: var(--emerald); font-weight: 500; }
    .compare-table .lose { color: var(--rose); }
    .compare-table .neutral { color: var(--muted); }
    .compare-table tr:last-child td { border-bottom: none; }

    /* FOOTER */
    .post-footer { margin-top: 4rem; padding-top: 2rem; border-top: 1px solid rgba(255,255,255,0.06); display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 1rem; }
    .back-link { font-family: 'DM Mono', monospace; font-size: 0.78rem; color: var(--muted); text-decoration: none; display: flex; align-items: center; gap: 0.5rem; transition: color 0.2s; }
    .back-link:hover { color: var(--amber); }
    .share-note { font-family: 'DM Mono', monospace; font-size: 0.7rem; color: var(--muted-dim); }

    footer { padding: 2rem 5%; border-top: 1px solid var(--border); display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 1rem; position: relative; z-index: 1; }
    .footer-links { display: flex; gap: 1.5rem; flex-wrap: wrap; }
    .footer-links a { font-family: 'DM Mono', monospace; font-size: 0.72rem; letter-spacing: 0.08em; text-transform: uppercase; color: var(--muted); text-decoration: none; transition: color 0.2s; }
    .footer-links a:hover { color: var(--amber); }
    .footer-copy { font-family: 'DM Mono', monospace; font-size: 0.72rem; color: var(--muted-dim); }
    .footer-logo { font-family: 'Syne', sans-serif; font-weight: 800; font-size: 0.95rem; text-decoration: none; color: var(--white); }
    .footer-logo span { color: var(--amber); }
  
/* Skip-to-content — WCAG 2.4.1 Level A */
.skip-link {
  position: absolute;
  top: -48px;
  left: 1rem;
  background: #10B981;
  color: #0F172A;
  padding: 0.5rem 1.1rem;
  border-radius: 0 0 6px 6px;
  z-index: 9999;
  font-size: 0.85rem;
  font-weight: 600;
  text-decoration: none;
  transition: top 0.15s ease;
}
.skip-link:focus { top: 0; outline: 2px solid #0F172A; outline-offset: 2px; }

/* Focus is a designed state, not a browser default. Nothing on this platform
   defined one except .skip-link, and five inputs actively removed the ring and
   signalled focus with a 1px border tint only — a colour-only indicator, which
   fails WCAG 1.4.1 and 2.4.7. White on these surfaces measures >13:1.
   :focus-visible, so pointer users never see a ring they did not ask for. */
:focus-visible {
  outline: 2px solid #F8FAFC;
  outline-offset: 2px;
  border-radius: 4px;
}
a:focus-visible, button:focus-visible, input:focus-visible,
[tabindex]:focus-visible, .btn:focus-visible {
  outline: 2px solid #F8FAFC;
  outline-offset: 2px;
}

/* Card titles are h3 so screen readers and search engines can navigate by
   heading; :where() keeps specificity at 0 so the existing class rules,
   which were written for divs, continue to control every visual property. */
:where(h3.work-name, h3.feature-title, h3.step-title, h3.svc-title, h3.prod-name, h3.post-title, h3.concept-title, h3.why-title, h3.card-title, h3.tier-name) {
  margin: 0; font-size: inherit; font-weight: inherit; line-height: inherit;
}

/* WCAG 2.5.8 — standalone nav and footer links computed ~20px tall against a
   24px minimum. min-height with inline-flex raises the hit area without adding
   padding that would shift the existing horizontal rhythm. */
.nav-links a, .footer-links a, .nav-mobile a, .nav-right a {
  display: inline-flex; align-items: center; min-height: 24px;
}