/* ============================================================
   blog.css — shared stylesheet for every page under /blog/

   The main site (index.html) keeps its CSS inline because it is one
   self-contained page. The blog is many pages, so the shared styles live
   here instead of being copy-pasted into each post.

   The design tokens below are deliberately identical to the ones in
   index.html: if I change an accent colour there, I change it here too.
   ============================================================ */

/* ============================================================
   Design tokens (mirrors index.html)
   ============================================================ */
:root {
  --accent: #6366f1;
  --accent-2: #8b5cf6;
  --accent-strong: #4f46e5;
  --accent-grad: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
  --accent-soft: rgba(99, 102, 241, 0.10);
  --accent-ring: rgba(99, 102, 241, 0.30);

  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --surface: #ffffff;
  --surface-2: #f1f5f9;
  --text: #0f172a;
  --text-muted: #475569;
  --text-subtle: #64748b;
  --border: #e7eaf0;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.04), 0 1px 3px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.06), 0 12px 28px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 18px 50px rgba(79, 70, 229, 0.16);
  --nav-bg: rgba(255, 255, 255, 0.72);
  --hero-glow-1: rgba(99, 102, 241, 0.22);
  --hero-glow-2: rgba(139, 92, 246, 0.18);
  --grid-line: rgba(15, 23, 42, 0.04);
  --code-bg: #f6f8fc;

  --max: 1120px;
  --measure: 720px;          /* comfortable reading width for article body */
  --radius: 18px;
  --radius-sm: 12px;
  --radius-lg: 26px;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-display: 'Plus Jakarta Sans', var(--font);
  --font-mono: ui-monospace, SFMono-Regular, 'SF Mono', Menlo, Consolas, 'Liberation Mono', monospace;
}

[data-theme="dark"] {
  --accent: #818cf8;
  --accent-2: #a78bfa;
  --accent-strong: #6366f1;
  --accent-grad: linear-gradient(135deg, #818cf8 0%, #a78bfa 100%);
  --accent-soft: rgba(129, 140, 248, 0.12);
  --accent-ring: rgba(129, 140, 248, 0.32);

  --bg: #0a0f1f;
  --bg-alt: #0d1426;
  --surface: #111a30;
  --surface-2: #16203a;
  --text: #eef2f9;
  --text-muted: #aab4c8;
  --text-subtle: #8090a8;
  --border: #223052;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 26px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 20px 56px rgba(0, 0, 0, 0.5);
  --nav-bg: rgba(10, 15, 31, 0.72);
  --hero-glow-1: rgba(99, 102, 241, 0.30);
  --hero-glow-2: rgba(139, 92, 246, 0.24);
  --grid-line: rgba(255, 255, 255, 0.035);
  --code-bg: #0f1830;
}

/* ============================================================
   Base
   ============================================================ */
* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; scroll-padding-top: 96px; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  transition: background-color 0.4s ease, color 0.4s ease;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { list-style: none; }

::selection { background: var(--accent); color: #fff; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

.skip-link {
  position: fixed; top: -80px; left: 16px; z-index: 200;
  background: var(--accent-strong); color: #fff;
  font-weight: 600; font-size: 0.9rem;
  padding: 10px 18px; border-radius: 10px;
  box-shadow: var(--shadow-md);
  transition: top 0.25s ease;
}
.skip-link:focus { top: 12px; }

.wrap { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 24px; }
.wrap-narrow { width: 100%; max-width: calc(var(--measure) + 48px); margin: 0 auto; padding: 0 24px; }

.accent-text {
  background: var(--accent-grad);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}

.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 0.78rem; font-weight: 600; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--accent);
  background: var(--accent-soft); padding: 6px 14px; border-radius: 999px;
}

/* ============================================================
   Buttons
   ============================================================ */
.btn {
  display: inline-flex; align-items: center; gap: 9px;
  font-weight: 600; font-size: 0.95rem;
  padding: 13px 22px; border-radius: 12px;
  cursor: pointer; border: 1px solid transparent;
  transition: transform 0.18s ease, box-shadow 0.25s ease, background 0.25s ease, border-color 0.25s ease;
  white-space: nowrap;
}
.btn svg { width: 18px; height: 18px; }
.btn-primary {
  background: var(--accent-grad); color: #fff;
  box-shadow: 0 8px 22px rgba(99, 102, 241, 0.32);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 30px rgba(99, 102, 241, 0.42); }
.btn-ghost {
  background: var(--surface); color: var(--text);
  border-color: var(--border); box-shadow: var(--shadow-sm);
}
.btn-ghost:hover { transform: translateY(-2px); border-color: var(--accent-ring); color: var(--accent); }

/* ============================================================
   Navbar (mirrors index.html)
   ============================================================ */
header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: var(--nav-bg);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease, background 0.3s ease, box-shadow 0.3s ease;
}
header.scrolled { border-bottom-color: var(--border); box-shadow: var(--shadow-sm); }
.scroll-progress {
  position: absolute; left: 0; bottom: -1px; height: 2px; width: 0;
  background: var(--accent-grad); border-radius: 999px;
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 70px; }

.brand { display: flex; align-items: center; gap: 11px; font-weight: 700; font-size: 1.02rem; letter-spacing: -0.01em; }
.brand .logo {
  width: 38px; height: 38px; border-radius: 11px;
  background: var(--accent-grad); color: #fff;
  display: grid; place-items: center;
  font-family: var(--font-display); font-weight: 800; font-size: 0.95rem;
  box-shadow: 0 6px 16px rgba(99, 102, 241, 0.35);
}

.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-links a {
  font-size: 0.92rem; font-weight: 500; color: var(--text-muted);
  padding: 8px 14px; border-radius: 9px; position: relative;
  transition: color 0.2s ease, background 0.2s ease;
}
.nav-links a:hover { color: var(--text); background: var(--surface-2); }
.nav-links a.active { color: var(--accent); }

.nav-actions { display: flex; align-items: center; gap: 10px; }

.icon-btn {
  width: 42px; height: 42px; border-radius: 11px;
  display: grid; place-items: center; cursor: pointer;
  background: var(--surface); border: 1px solid var(--border);
  color: var(--text-muted); transition: all 0.2s ease;
}
.icon-btn:hover { color: var(--accent); border-color: var(--accent-ring); transform: translateY(-1px); }
.icon-btn svg { width: 20px; height: 20px; }
.theme-toggle .moon { display: none; }
[data-theme="dark"] .theme-toggle .sun { display: none; }
[data-theme="dark"] .theme-toggle .moon { display: block; }

.lang-toggle {
  display: inline-flex; align-items: center; justify-content: center;
  width: auto; gap: 6px; padding: 0 13px;
  font-family: var(--font); font-weight: 700; font-size: 0.82rem;
  letter-spacing: 0.04em; color: var(--text-muted);
}
.lang-toggle:hover { color: var(--accent); }
.lang-toggle svg { width: 17px; height: 17px; }
.lang-toggle .lang-code { line-height: 1; }

.hamburger { display: none; }

.nav-backdrop {
  position: fixed; inset: 0; z-index: 98;
  background: rgba(8, 12, 26, 0.45);
  opacity: 0; pointer-events: none;
  transition: opacity 0.3s ease;
}
.nav-backdrop.show { opacity: 1; pointer-events: auto; }

/* ============================================================
   Blog hero (listing page)
   ============================================================ */
.blog-hero { padding: 132px 0 56px; position: relative; overflow: hidden; }
.blog-hero::before {
  content: ""; position: absolute; inset: 0; z-index: -2;
  background:
    radial-gradient(620px circle at 15% 8%, var(--hero-glow-1), transparent 55%),
    radial-gradient(560px circle at 88% 22%, var(--hero-glow-2), transparent 52%);
}
.blog-hero::after {
  content: ""; position: absolute; inset: 0; z-index: -2;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 54px 54px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 30%, transparent 75%);
}
.blog-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 5.5vw, 3.4rem);
  font-weight: 800; line-height: 1.06; letter-spacing: -0.03em;
  margin: 20px 0 14px;
}
.blog-hero .lead { font-size: 1.08rem; color: var(--text-muted); max-width: 620px; }
.blog-hero .hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }

/* ============================================================
   Tag filter
   ============================================================ */
.filter-bar {
  display: flex; flex-wrap: wrap; align-items: center; gap: 10px;
  padding: 0 0 34px;
}
.filter-label {
  font-size: 0.8rem; font-weight: 600; letter-spacing: 0.06em;
  text-transform: uppercase; color: var(--text-subtle); margin-right: 4px;
}
.tag-btn {
  font-family: var(--font); font-size: 0.88rem; font-weight: 500;
  padding: 8px 15px; border-radius: 11px; cursor: pointer;
  background: var(--surface-2); border: 1px solid var(--border); color: var(--text-muted);
  transition: all 0.18s ease;
}
.tag-btn:hover { color: var(--accent); border-color: var(--accent-ring); background: var(--accent-soft); transform: translateY(-2px); }
.tag-btn[aria-pressed="true"] {
  color: #fff; background: var(--accent-grad); border-color: transparent;
  box-shadow: 0 6px 16px rgba(99, 102, 241, 0.3);
}

/* ============================================================
   Post list
   ============================================================ */
/* A responsive grid, so a long archive stays browsable rather than becoming
   one endless column. */
.post-list {
  display: grid; gap: 22px; padding-bottom: 40px;
  grid-template-columns: repeat(auto-fill, minmax(310px, 1fr));
  align-items: start;
}

.post-card {
  position: relative; display: flex; flex-direction: column; height: 100%;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}
.post-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: var(--accent-ring); }
.post-card.is-hidden { display: none; }

.post-card .cover {
  display: block; aspect-ratio: 16 / 9;
  background: var(--surface-2); border-bottom: 1px solid var(--border);
  overflow: hidden;
}
.post-card .cover img {
  width: 100%; height: 100%; object-fit: cover;
  transition: transform 0.4s cubic-bezier(0.22, 1, 0.36, 1);
}
.post-card:hover .cover img { transform: scale(1.04); }

.post-card .card-body {
  display: flex; flex-direction: column; flex: 1 1 auto;
  padding: 22px 24px 24px;
}

.post-meta {
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px 12px;
  font-size: 0.82rem; color: var(--text-subtle); margin-bottom: 12px;
}
.post-meta .dot { width: 4px; height: 4px; border-radius: 50%; background: var(--text-subtle); opacity: 0.5; }
.post-meta .pill {
  font-size: 0.74rem; font-weight: 600; letter-spacing: 0.03em;
  color: var(--accent); background: var(--accent-soft);
  padding: 4px 10px; border-radius: 999px;
}
/* On a card the category sits on its own line, so "12 May 2019 · 3 min read"
   never wraps mid-way and strands the separator dot. */
.post-card .post-meta { flex-direction: column; align-items: flex-start; gap: 9px; }
.post-card .post-meta .meta-line { display: flex; align-items: center; gap: 10px; white-space: nowrap; }

.post-card h2 {
  font-family: var(--font-display);
  font-size: 1.18rem; font-weight: 700; letter-spacing: -0.015em; line-height: 1.3;
  margin-bottom: 10px;
  display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden;
}
.post-card:hover h2 { color: var(--accent); }
.post-card .excerpt {
  display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden;
  color: var(--text-muted); font-size: 0.94rem; line-height: 1.6;
}
.post-card .more {
  display: inline-flex; align-items: center; gap: 7px;
  margin-top: auto; padding-top: 18px;
  font-size: 0.88rem; font-weight: 600; color: var(--accent);
}
.post-card .more svg { width: 16px; height: 16px; transition: transform 0.2s ease; }
.post-card:hover .more svg { transform: translateX(4px); }

/* Shown only when the tag filter matches nothing */
.empty-state {
  display: none;
  text-align: center; padding: 56px 24px;
  background: var(--surface); border: 1px dashed var(--border);
  border-radius: var(--radius-lg); color: var(--text-muted);
}
.empty-state.show { display: block; }

/* ============================================================
   Article (post page)
   ============================================================ */
.post-head { padding: 124px 0 0; }
.back-link {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 0.9rem; font-weight: 600; color: var(--text-muted);
  transition: color 0.2s ease, gap 0.2s ease;
}
.back-link svg { width: 16px; height: 16px; }
.back-link:hover { color: var(--accent); gap: 11px; }

.post-head h1 {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4.6vw, 2.9rem);
  font-weight: 800; line-height: 1.12; letter-spacing: -0.03em;
  margin: 22px 0 16px;
}
.post-head .standfirst {
  font-size: 1.15rem; line-height: 1.65; color: var(--text-muted); font-weight: 500;
}
.post-head .post-meta { margin: 22px 0 0; }
.post-head .rule { height: 1px; background: var(--border); margin: 34px 0 0; }

/* Optional lead image. Cover art came in wildly different sizes — some only a
   few hundred pixels — so never scale one up past its natural size, and cap
   how much vertical space it may claim before the article starts. */
.post-figure { margin: 34px 0 0; text-align: center; }
.post-figure img {
  display: inline-block;
  width: auto; max-width: 100%; max-height: 420px;
  border-radius: var(--radius); border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

/* Table of contents — built by blog.js from the h2s in .prose */
.toc {
  margin: 34px 0 0; padding: 20px 24px;
  background: var(--bg-alt); border: 1px solid var(--border); border-radius: var(--radius);
}
.toc-title {
  font-size: 0.78rem; font-weight: 700; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--text-subtle); margin-bottom: 12px;
}
.toc ol { list-style: none; counter-reset: toc; }
.toc li { counter-increment: toc; margin-bottom: 7px; }
.toc li:last-child { margin-bottom: 0; }
.toc a {
  display: inline-flex; gap: 10px; font-size: 0.94rem; color: var(--text-muted);
  transition: color 0.2s ease;
}
.toc a::before { content: counter(toc) "."; color: var(--accent); font-weight: 600; }
.toc a:hover { color: var(--accent); }

/* ------------------------------------------------------------
   .prose — the article body. Everything a post needs, styled once.
   ------------------------------------------------------------ */
.prose { padding: 12px 0 0; font-size: 1.06rem; }
.prose > * + * { margin-top: 1.15em; }

.prose h2 {
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 3vw, 1.75rem);
  font-weight: 700; letter-spacing: -0.02em; line-height: 1.25;
  margin-top: 2.2em; margin-bottom: 0.1em;
}
.prose h3 {
  font-family: var(--font-display);
  font-size: 1.15rem; font-weight: 700; letter-spacing: -0.01em;
  margin-top: 1.8em; margin-bottom: 0.1em;
}
.prose h4 { font-size: 1.02rem; font-weight: 700; margin-top: 1.5em; margin-bottom: 0.1em; }

/* Anchor link that appears next to a heading on hover */
.prose h2, .prose h3 { position: relative; scroll-margin-top: 96px; }
.prose .anchor {
  position: absolute; left: -1.1em; top: 50%; transform: translateY(-50%);
  color: var(--accent); opacity: 0; font-weight: 600; text-decoration: none;
  transition: opacity 0.18s ease; padding: 0 0.25em;
}
.prose h2:hover .anchor, .prose h3:hover .anchor, .prose .anchor:focus-visible { opacity: 1; }

.prose p { color: var(--text-muted); }
.prose .lead { font-size: 1.16rem; color: var(--text); font-weight: 500; }

.prose strong, .prose b { color: var(--text); font-weight: 700; }
.prose em, .prose i { font-style: italic; }

.prose a:not(.anchor) {
  color: var(--accent); font-weight: 500;
  border-bottom: 1px solid var(--accent-ring);
  transition: border-color 0.2s ease, color 0.2s ease;
}
.prose a:not(.anchor):hover { border-bottom-color: var(--accent); }

.prose ul, .prose ol { padding-left: 0; color: var(--text-muted); }
.prose ul li, .prose ol li { position: relative; padding-left: 26px; margin-bottom: 9px; }
.prose ul li::before {
  content: ""; position: absolute; left: 3px; top: 0.62em;
  width: 7px; height: 7px; border-radius: 2px;
  background: var(--accent-grad); transform: rotate(45deg);
}
.prose ol { counter-reset: prose-ol; }
.prose ol li { counter-increment: prose-ol; }
.prose ol li::before {
  content: counter(prose-ol) ".";
  position: absolute; left: 0; top: 0;
  color: var(--accent); font-weight: 700; font-size: 0.95em;
}
.prose li > ul, .prose li > ol { margin-top: 9px; }

.prose blockquote {
  padding: 4px 0 4px 22px;
  border-left: 3px solid var(--accent);
  color: var(--text); font-size: 1.1rem; font-style: italic;
}
.prose blockquote p { color: inherit; }
.prose blockquote cite {
  display: block; margin-top: 10px;
  font-size: 0.88rem; font-style: normal; font-weight: 600; color: var(--text-subtle);
}

.prose code {
  font-family: var(--font-mono); font-size: 0.88em;
  background: var(--code-bg); border: 1px solid var(--border);
  padding: 0.15em 0.42em; border-radius: 6px; color: var(--text);
}
.prose pre {
  background: var(--code-bg); border: 1px solid var(--border);
  border-radius: var(--radius-sm); padding: 18px 20px;
  overflow-x: auto; font-size: 0.9rem; line-height: 1.6;
}
.prose pre code { background: none; border: none; padding: 0; font-size: inherit; }

.prose img {
  /* Screenshots keep their own size (scaled down to fit, never up). */
  width: auto; max-width: 100%; margin-inline: auto;
  border-radius: var(--radius); border: 1px solid var(--border);
}
.prose figure { margin-top: 1.6em; text-align: center; }
.prose figure img { display: inline-block; }
.prose figcaption {
  margin-top: 10px; font-size: 0.86rem; color: var(--text-subtle); text-align: center;
}

.prose hr { border: none; height: 1px; background: var(--border); margin: 2.6em 0; }

/* Tables scroll on their own so the page never scrolls sideways */
.prose .table-scroll { overflow-x: auto; margin-top: 1.6em; }
.prose table { width: 100%; border-collapse: collapse; font-size: 0.95rem; }
.prose th, .prose td { padding: 11px 14px; text-align: left; border-bottom: 1px solid var(--border); }
.prose th { font-weight: 700; color: var(--text); background: var(--bg-alt); white-space: nowrap; }
.prose td { color: var(--text-muted); }

/* Callout box for asides / takeaways */
.prose .callout {
  display: flex; gap: 14px; align-items: flex-start;
  background: var(--accent-soft); border: 1px solid var(--accent-ring);
  border-radius: var(--radius); padding: 20px 22px; margin-top: 1.6em;
}
.prose .callout .ico { flex-shrink: 0; color: var(--accent); }
.prose .callout .ico svg { width: 22px; height: 22px; }
.prose .callout p { color: var(--text); }
.prose .callout > div > * + * { margin-top: 0.7em; }

/* ============================================================
   Post footer: tags, share, prev/next
   ============================================================ */
.post-foot { padding: 48px 0 0; }
.post-foot .rule { height: 1px; background: var(--border); margin-bottom: 32px; }

.post-tags { display: flex; flex-wrap: wrap; gap: 10px; }
.post-tags a {
  font-size: 0.86rem; font-weight: 500; padding: 7px 14px; border-radius: 10px;
  background: var(--surface-2); border: 1px solid var(--border); color: var(--text-muted);
  transition: all 0.18s ease;
}
.post-tags a:hover { color: var(--accent); border-color: var(--accent-ring); background: var(--accent-soft); transform: translateY(-2px); }

.share-row {
  display: flex; flex-wrap: wrap; align-items: center; gap: 10px;
  margin-top: 26px;
}
.share-row .share-label { font-size: 0.86rem; font-weight: 600; color: var(--text-subtle); margin-right: 4px; }
.share-btn {
  position: relative;
  width: 40px; height: 40px; border-radius: 10px;
  display: grid; place-items: center; cursor: pointer;
  background: var(--surface); border: 1px solid var(--border); color: var(--text-muted);
  transition: all 0.2s ease;
}
.share-btn:hover { color: #fff; background: var(--accent-grad); border-color: transparent; transform: translateY(-2px); }
.share-btn svg { width: 18px; height: 18px; }
.share-btn::after {
  content: attr(data-tip);
  position: absolute; bottom: calc(100% + 8px); left: 50%; transform: translateX(-50%);
  background: rgba(15, 23, 42, 0.92); color: #fff;
  font-size: 0.75rem; font-weight: 600;
  padding: 4px 10px; border-radius: 6px; white-space: nowrap;
  opacity: 0; pointer-events: none; transition: opacity 0.2s ease;
}
.share-btn.copied::after { opacity: 1; }

.post-nav {
  display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 40px;
}
.post-nav a {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 20px 22px; box-shadow: var(--shadow-sm);
  transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
}
.post-nav a:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); border-color: var(--accent-ring); }
.post-nav .dir {
  display: block; font-size: 0.76rem; font-weight: 700; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--accent); margin-bottom: 7px;
}
.post-nav .ttl { font-weight: 600; color: var(--text); line-height: 1.4; }
.post-nav a.next { text-align: right; }
.post-nav .spacer { /* keeps a lone "next" card in the right column */ }

/* CTA at the end of a post */
.post-cta {
  margin-top: 48px; position: relative; overflow: hidden;
  background: var(--accent-grad); border-radius: var(--radius-lg);
  padding: 44px 36px; text-align: center; color: #fff;
  box-shadow: var(--shadow-lg);
}
.post-cta::before {
  content: ""; position: absolute; inset: 0; z-index: 0;
  background:
    radial-gradient(420px circle at 20% 10%, rgba(255,255,255,0.22), transparent 50%),
    radial-gradient(420px circle at 85% 90%, rgba(255,255,255,0.16), transparent 50%);
}
.post-cta > * { position: relative; z-index: 1; }
.post-cta h2 { font-family: var(--font-display); font-size: clamp(1.4rem, 3vw, 1.9rem); font-weight: 800; letter-spacing: -0.02em; margin-bottom: 10px; }
.post-cta p { opacity: 0.92; max-width: 460px; margin: 0 auto 26px; }
.btn-white { background: #fff; color: var(--accent-strong); box-shadow: 0 10px 26px rgba(0,0,0,0.18); }
.btn-white:hover { transform: translateY(-2px); box-shadow: 0 14px 32px rgba(0,0,0,0.24); }

/* ============================================================
   Footer (mirrors index.html)
   ============================================================ */
footer { padding: 48px 0 40px; margin-top: 80px; border-top: 1px solid var(--border); }
.foot { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 20px; }
.foot .brand { font-size: 1rem; }
.foot-links { display: flex; gap: 8px; }
.foot-links a {
  width: 40px; height: 40px; border-radius: 10px; display: grid; place-items: center;
  background: var(--surface); border: 1px solid var(--border); color: var(--text-muted);
  transition: all 0.2s ease;
}
.foot-links a:hover { color: #fff; background: var(--accent-grad); border-color: transparent; transform: translateY(-2px); }
.foot-links svg { width: 19px; height: 19px; }
.foot-note { width: 100%; text-align: center; color: var(--text-subtle); font-size: 0.85rem; margin-top: 28px; padding-top: 24px; border-top: 1px solid var(--border); }

/* ============================================================
   Reveal animation + back to top
   ============================================================ */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity 0.7s ease, transform 0.7s cubic-bezier(0.22, 1, 0.36, 1); }
.reveal.visible { opacity: 1; transform: none; }
.reveal.d1 { transition-delay: 0.08s; }
.reveal.d2 { transition-delay: 0.16s; }
.reveal.d3 { transition-delay: 0.24s; }
.reveal.d4 { transition-delay: 0.32s; }
.reveal.d5 { transition-delay: 0.40s; }

.to-top {
  position: fixed; right: 22px; bottom: 22px; z-index: 90;
  width: 46px; height: 46px; border-radius: 50%;
  border: none; cursor: pointer;
  display: grid; place-items: center;
  background: var(--accent-grad); color: #fff;
  box-shadow: 0 10px 24px rgba(99, 102, 241, 0.35);
  opacity: 0; transform: translateY(14px); pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease, box-shadow 0.25s ease;
}
.to-top.show { opacity: 1; transform: translateY(0); pointer-events: auto; }
.to-top:hover { transform: translateY(-3px); box-shadow: 0 14px 30px rgba(99, 102, 241, 0.45); }
.to-top svg { width: 20px; height: 20px; }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 1080px) {
  .nav-links {
    position: fixed; top: 70px; right: 0; left: 0;
    flex-direction: column; align-items: stretch; gap: 4px;
    background: var(--bg); border-bottom: 1px solid var(--border);
    padding: 16px 24px 24px; box-shadow: var(--shadow-md);
    transform: translateY(-120%); visibility: hidden;
    transition: transform 0.34s cubic-bezier(0.22, 1, 0.36, 1), visibility 0.34s;
    max-height: calc(100vh - 70px); overflow-y: auto;
  }
  .nav-links.open { transform: translateY(0); visibility: visible; }
  .nav-links a { padding: 13px 16px; font-size: 1rem; border-radius: 11px; }
  .hamburger { display: grid; }
}

@media (max-width: 720px) {
  .blog-hero { padding: 116px 0 40px; }
  .post-head { padding: 112px 0 0; }
  .post-card { padding: 24px 22px; }
  .post-nav { grid-template-columns: 1fr; }
  .post-nav a.next { text-align: left; }
  .post-cta { padding: 34px 24px; }
  .to-top { right: 16px; bottom: 16px; }
  .prose { font-size: 1.02rem; }
  .prose .anchor { display: none; }
}

@media (max-width: 460px) {
  .brand .label { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; scroll-behavior: auto !important; }
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* ============================================================
   Print — a post should print as a clean document
   ============================================================ */
@media print {
  header, .to-top, .share-row, .post-nav, .post-cta, .filter-bar, footer .foot-links, .back-link, .toc { display: none !important; }
  body { background: #fff; color: #000; }
  .prose p, .prose li, .prose td { color: #222; }
  .prose a:not(.anchor) { color: #000; border-bottom: none; text-decoration: underline; }
}