/* ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
   Teacher and Me — blog stylesheet (static pages, generated by
   scripts/blog/plugin.ts). The blog is an extension of the APP SHELL, so the
   tokens below are a curated copy of src/styles/theme.css (keep in sync by
   hand — the app's Tailwind pipeline only scans src/, so static HTML cannot
   share its utilities). Fonts are the app's Nunito/Inter, copied at build
   from @fontsource into /blog-assets/fonts/; the metric-override fallbacks
   mirror src/styles/fonts.css (Capsize) for ≈0 CLS on font swap.
   ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ */

@font-face {
  font-family: "Nunito";
  font-style: normal;
  font-display: swap;
  font-weight: 700;
  src: url("/blog-assets/fonts/nunito-latin-700-normal.woff2") format("woff2");
}
@font-face {
  font-family: "Nunito";
  font-style: normal;
  font-display: swap;
  font-weight: 800;
  src: url("/blog-assets/fonts/nunito-latin-800-normal.woff2") format("woff2");
}
@font-face {
  font-family: "Inter";
  font-style: normal;
  font-display: swap;
  font-weight: 400;
  src: url("/blog-assets/fonts/inter-latin-400-normal.woff2") format("woff2");
}
@font-face {
  font-family: "Inter";
  font-style: normal;
  font-display: swap;
  font-weight: 600;
  src: url("/blog-assets/fonts/inter-latin-600-normal.woff2") format("woff2");
}
@font-face {
  font-family: "Inter";
  font-style: normal;
  font-display: swap;
  font-weight: 700;
  src: url("/blog-assets/fonts/inter-latin-700-normal.woff2") format("woff2");
}
/* Metric fallbacks — same overrides as src/styles/fonts.css */
@font-face {
  font-family: "Nunito Fallback";
  src: local('Arial'), local('ArialMT');
  ascent-override: 99.7134%;
  descent-override: 34.8159%;
  line-gap-override: 0%;
  size-adjust: 101.3906%;
}
@font-face {
  font-family: "Inter Fallback";
  src: local('Arial'), local('ArialMT');
  ascent-override: 90.4365%;
  descent-override: 22.518%;
  line-gap-override: 0%;
  size-adjust: 107.1194%;
}

:root {
  /* Copied from src/styles/theme.css — core palette only */
  --color-primary: #5457e0;
  --color-primary-light: #818cf8;
  --color-primary-dark: #3b3eb8;
  --color-secondary: #ffd93d;
  --color-secondary-dark: #8a6610;
  --color-success: #0a8060;
  --color-danger: #c84b4b;
  --color-cloud: #eef0ff;
  --color-surface: #ffffff;
  --color-text-primary: #1e1b4b;
  /* App token is #64748b, but that's only 4.2:1 on the cloud bg — below AA
     for normal text. #56657c is the same slate family at 5.2:1 on cloud. */
  --color-text-secondary: #56657c;
  --color-border: #e0e2ff;
  --color-accent-sky: #e7e9ff;

  --font-heading: "Nunito", "Nunito Fallback", "Inter", "Inter Fallback", system-ui, sans-serif;
  --font-body: "Inter", "Inter Fallback", system-ui, sans-serif;

  --radius-sm: 12px;
  --radius-md: 20px;
  --radius-lg: 28px;

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-6: 24px;
  --space-8: 32px;
  --space-12: 48px;
  --space-16: 64px;

  --shadow-card: 0 4px 14px -4px color-mix(in srgb, var(--color-primary) 18%, transparent),
    0 2px 4px -2px rgb(0 0 0 / 0.06);

  --content-width: 72ch;
  --page-width: 960px;
}

/* ─── Reset & base ─────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}
body {
  font-family: var(--font-body);
  background: var(--color-cloud);
  color: var(--color-text-primary);
  font-size: 1rem;
  line-height: 1.7;
  min-height: 100vh;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-primary-dark); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--color-primary); }
:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 2px; border-radius: 2px; }

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--color-text-primary);
  line-height: 1.2;
  overflow-wrap: break-word;
}
h1 { font-size: clamp(1.9rem, 1.4rem + 2.2vw, 2.75rem); font-weight: 800; letter-spacing: -0.02em; }
h2 { font-size: clamp(1.35rem, 1rem + 1.5vw, 1.85rem); }
h3 { font-size: clamp(1.1rem, 0.9rem + 0.9vw, 1.35rem); }

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

.skip-link {
  position: absolute; left: var(--space-4); top: -100px; z-index: 10;
  background: var(--color-surface); color: var(--color-primary-dark);
  padding: var(--space-2) var(--space-4); border-radius: var(--radius-sm);
  font-weight: 600; box-shadow: var(--shadow-card);
}
.skip-link:focus { top: var(--space-4); }

.draft-banner {
  background: #fff3cc; color: var(--color-secondary-dark);
  border-bottom: 1px solid #f0d98c;
  text-align: center; font-weight: 600; font-size: 0.875rem;
  padding: var(--space-2) var(--space-4);
}
.draft-tag {
  display: inline-block; vertical-align: middle; margin-left: var(--space-2);
  background: #fff3cc; color: var(--color-secondary-dark);
  font-family: var(--font-body); font-size: 0.7rem; font-weight: 700;
  letter-spacing: 0.06em; text-transform: uppercase;
  padding: 2px 8px; border-radius: 999px;
}

.container { max-width: var(--page-width); margin: 0 auto; padding: 0 var(--space-6); }

/* ─── Header / footer chrome ───────────────────────────────────────────── */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  gap: var(--space-4); padding-top: var(--space-3); padding-bottom: var(--space-3);
  flex-wrap: wrap;
}
.brand {
  font-family: var(--font-heading); font-weight: 800; font-size: 1.15rem;
  color: var(--color-primary); text-decoration: none;
}
.brand:hover { color: var(--color-primary-dark); }
.header-nav { display: flex; align-items: center; gap: var(--space-4); flex-wrap: wrap; }
.header-nav a { font-size: 0.9rem; font-weight: 600; text-decoration: none; color: var(--color-text-primary); }
.header-nav a:hover { color: var(--color-primary); }
.locale-switch { color: var(--color-primary-dark); }
.btn-header {
  background: var(--color-primary); color: #fff !important;
  padding: var(--space-2) var(--space-4); border-radius: 999px;
}
.btn-header:hover { background: var(--color-primary-dark); }

.site-footer {
  border-top: 1px solid var(--color-border);
  margin-top: var(--space-16);
  padding: var(--space-8) var(--space-6);
  text-align: center; font-size: 0.875rem; color: var(--color-text-secondary);
}
.site-footer a { color: inherit; }
.footer-tagline { margin-top: var(--space-2); }

/* ─── Post & index shells ──────────────────────────────────────────────── */
main { display: block; }
.post, .index-header { padding-top: var(--space-8); }
.post-header h1 { max-width: 26ch; }
.index-header h1 { margin-bottom: var(--space-2); }
.index-tagline { color: var(--color-text-secondary); max-width: 60ch; margin-bottom: var(--space-8); }

.breadcrumb { font-size: 0.8rem; margin-bottom: var(--space-4); color: var(--color-text-secondary); }
.breadcrumb ol { list-style: none; display: flex; flex-wrap: wrap; gap: var(--space-1); }
.breadcrumb li + li::before { content: "›"; margin: 0 var(--space-2); color: var(--color-text-secondary); }
.breadcrumb a { color: inherit; text-decoration: none; }
.breadcrumb a:hover { color: var(--color-primary); text-decoration: underline; }
.breadcrumb [aria-current="page"] { color: var(--color-text-primary); font-weight: 600; }

.byline {
  margin: var(--space-3) 0 var(--space-6);
  font-size: 0.875rem; color: var(--color-text-secondary);
  display: flex; flex-wrap: wrap; align-items: baseline;
}
.byline-author { font-weight: 600; color: var(--color-text-primary); }
.byline-updated { font-weight: 600; color: var(--color-success); }
.byline-sep { margin: 0 var(--space-2); }

.post-cover { margin: 0 0 var(--space-8); }
.post-cover img { border-radius: var(--radius-md); box-shadow: var(--shadow-card); }
.post-cover figcaption { font-size: 0.8rem; color: var(--color-text-secondary); margin-top: var(--space-2); }

/* ─── Table of contents ────────────────────────────────────────────────── */
.toc {
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: var(--space-4) var(--space-6);
  margin-bottom: var(--space-8); max-width: var(--content-width);
}
.toc h2 { font-size: 0.95rem; margin-bottom: var(--space-2); }
.toc ol { list-style: none; }
.toc > ol > li { margin: var(--space-1) 0; }
.toc ol ol { padding-left: var(--space-4); font-size: 0.9em; }
.toc a { text-decoration: none; color: var(--color-primary-dark); }
.toc a:hover { text-decoration: underline; }

/* ─── Article body ─────────────────────────────────────────────────────── */
.post-body, .faq, .author-card { max-width: var(--content-width); }
.post-body > * + * { margin-top: var(--space-4); }
.post-body h2 { margin-top: var(--space-12); }
.post-body h3 { margin-top: var(--space-8); }
.post-body ul, .post-body ol { padding-left: 1.4em; }
.post-body li + li { margin-top: var(--space-2); }
.post-body blockquote {
  border-left: 4px solid var(--color-primary-light);
  padding: var(--space-2) var(--space-4);
  color: var(--color-text-secondary);
  background: var(--color-surface);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
.post-body code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.9em; background: var(--color-accent-sky);
  padding: 0.1em 0.35em; border-radius: 6px;
}
.post-body pre {
  background: #23214d; color: #eef0ff; padding: var(--space-4);
  border-radius: var(--radius-sm); overflow-x: auto;
}
.post-body pre code { background: none; padding: 0; color: inherit; }
.post-body hr { border: 0; border-top: 1px solid var(--color-border); margin: var(--space-8) 0; }
.post-body figure { margin: var(--space-6) 0; }
.post-body figure img { border-radius: var(--radius-sm); box-shadow: var(--shadow-card); }
.post-body figcaption { font-size: 0.8rem; color: var(--color-text-secondary); margin-top: var(--space-2); }

.heading-anchor {
  margin-left: var(--space-2); text-decoration: none; font-weight: 400;
  color: var(--color-primary-light); opacity: 0;
}
h2:hover .heading-anchor, h3:hover .heading-anchor,
.heading-anchor:focus-visible { opacity: 1; }
@media (hover: none) { .heading-anchor { opacity: 0.6; } }

.table-wrap { overflow-x: auto; margin: var(--space-6) 0; border-radius: var(--radius-sm); box-shadow: var(--shadow-card); }
.post-body table { border-collapse: collapse; width: 100%; background: var(--color-surface); font-size: 0.925rem; }
.post-body th, .post-body td { padding: var(--space-2) var(--space-3); border-bottom: 1px solid var(--color-border); text-align: left; vertical-align: top; }
.post-body thead th { background: var(--color-accent-sky); font-family: var(--font-heading); }
.post-body tbody tr:last-child td { border-bottom: 0; }

.callout {
  border: 1px solid var(--color-border); border-left-width: 4px;
  background: var(--color-surface); border-radius: var(--radius-sm);
  padding: var(--space-3) var(--space-4);
}
.callout > * + * { margin-top: var(--space-2); }
.callout-label { font-weight: 700; font-family: var(--font-heading); }
.callout--note { border-left-color: var(--color-primary-light); }
.callout--tip { border-left-color: var(--color-success); }
.callout--tip .callout-label { color: var(--color-success); }
.callout--warning { border-left-color: var(--color-danger); }
.callout--warning .callout-label { color: var(--color-danger); }

/* GFM footnotes → visible "Sources" section */
.post-body section[data-footnotes] {
  margin-top: var(--space-12); padding-top: var(--space-4);
  border-top: 1px solid var(--color-border);
  font-size: 0.875rem; color: var(--color-text-secondary);
}
.footnotes-title { font-size: 1.1rem; }
[data-footnote-ref] { text-decoration: none; font-weight: 600; }

/* ─── FAQ ──────────────────────────────────────────────────────────────── */
.faq { margin-top: var(--space-12); }
.faq-item {
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-sm); padding: var(--space-4);
  margin-top: var(--space-3);
}
.faq-item h3 { font-size: 1.05rem; margin-bottom: var(--space-2); }
.faq-answer > * + * { margin-top: var(--space-2); }

/* ─── CTA banner ───────────────────────────────────────────────────────── */
.cta-banner {
  margin: var(--space-12) 0 0; padding: var(--space-8);
  max-width: var(--content-width);
  background: linear-gradient(130deg, color-mix(in srgb, var(--color-primary) 9%, white) 0%, var(--color-surface) 58%);
  border: 1px solid var(--color-border); border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}
.cta-heading { margin-bottom: var(--space-2); }
.cta-actions { margin-top: var(--space-4); display: flex; gap: var(--space-4); align-items: center; flex-wrap: wrap; }
.btn-cta {
  display: inline-block; background: var(--color-primary); color: #fff;
  font-weight: 700; text-decoration: none;
  padding: var(--space-3) var(--space-6); border-radius: 999px;
  min-height: 44px;
}
.btn-cta:hover { background: var(--color-primary-dark); color: #fff; }
.cta-secondary { font-weight: 600; }

.author-card {
  margin-top: var(--space-12); padding: var(--space-4) var(--space-6);
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-sm); font-size: 0.9rem;
}

/* ─── Related posts / index cards ──────────────────────────────────────── */
.related { margin-top: var(--space-12); }
.related-grid, .post-list { list-style: none; }
.related-grid {
  display: grid; gap: var(--space-4); margin-top: var(--space-4);
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}
.related-card {
  display: flex; flex-direction: column; gap: var(--space-2); height: 100%;
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: var(--space-4);
  text-decoration: none; color: inherit; box-shadow: var(--shadow-card);
}
.related-card:hover { border-color: var(--color-primary-light); }
.related-card-title { font-family: var(--font-heading); font-weight: 700; color: var(--color-primary-dark); }
.related-card-desc { font-size: 0.875rem; color: var(--color-text-secondary); }
.related-card-meta { font-size: 0.8rem; color: var(--color-text-secondary); margin-top: auto; }

.post-list { display: grid; gap: var(--space-6); }
.post-card {
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: var(--space-6);
  box-shadow: var(--shadow-card);
}
.post-card--thumb { display: grid; grid-template-columns: 220px 1fr; gap: var(--space-6); align-items: start; }
.post-card-thumb img { border-radius: var(--radius-sm); }
@media (max-width: 639px) {
  .post-card--thumb { display: block; }
  .post-card-thumb { margin-bottom: var(--space-4); }
}
.post-card-title { font-size: 1.3rem; }
.post-card-title a { text-decoration: none; color: var(--color-text-primary); }
.post-card-title a:hover { color: var(--color-primary); }
.post-card-desc { color: var(--color-text-secondary); margin-top: var(--space-2); }
.post-card-meta { font-size: 0.85rem; color: var(--color-text-secondary); margin-top: var(--space-3); }

@media (max-width: 640px) {
  .container { padding: 0 var(--space-4); }
  .post-card { padding: var(--space-4); }
  .cta-banner { padding: var(--space-6); }
}