/* Calculator Constellation — tool-dense theme, iteration 2.
 * Goal: feel like a calculator, not a magazine.
 * Single column, white bg, Inter Tight throughout.
 * Fraunces only on the result number (the payoff moment).
 */

/* Webfont @font-face declarations.
 * font-display: optional → fallback used if WOFF2 not in cache within ~100ms.
 * size-adjust + ascent/descent overrides → fallback occupies the SAME visual
 * space as the webfont, so font-swap mid-render produces zero layout shift
 * (Lighthouse CLS metric was catching this previously).
 *
 * Override values calibrated against the system-ui / Georgia fallback stack
 * defined in --sans / --serif below.
 */
@font-face {
  font-family: 'Fraunces';
  font-style: normal;
  font-weight: 600 900;
  font-display: optional;
  src: url('fonts/fraunces-latin.woff2') format('woff2');
  unicode-range: U+0020-007F, U+00A0-00FF, U+2000-206F, U+20AC, U+2212;
  size-adjust: 100%;
  ascent-override: 95%;
  descent-override: 25%;
  line-gap-override: 0%;
}
@font-face {
  font-family: 'Inter Tight';
  font-style: normal;
  font-weight: 300 700;
  font-display: optional;
  src: url('fonts/inter-tight-latin.woff2') format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215;
  size-adjust: 107%;
  ascent-override: 90%;
  descent-override: 22.5%;
  line-gap-override: 0%;
}

/* ---------- Tokens ---------- */
:root {
  --accent: #0a7a5f;
  --accent-dark: #06513f;
  --accent-soft: #e6f2ee;
  --tint: #f7faf9;
  --ink: #131316;
  --ink-soft: #4a4a52;
  --ink-faint: #6c6c74;  /* WCAG AA on white: ratio ~5.1 (was #7a7a82 = 4.25, just under) */
  --line: #e4e4e7;
  --line-strong: #c5c5c8;
  --bg: #ffffff;
  --bg-soft: #f7f7f8;
  --sans: 'Inter Tight', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, system-ui, sans-serif;
  --serif: 'Fraunces', 'Iowan Old Style', Georgia, 'Times New Roman', serif;
  --rule: 2px;
  --radius: 10px;
  --radius-sm: 6px;
}

body[data-site="percentagecalculator"] { --accent: #0a7a5f; --accent-dark: #06513f; --accent-soft: #e6f2ee; --tint: #f7faf9; }
body[data-site="vatcalculator"]        { --accent: #5b3a8e; --accent-dark: #3e2562; --accent-soft: #efe9f5; --tint: #faf8fc; }
body[data-site="agecalculator"]        { --accent: #c2682c; --accent-dark: #8f4b1e; --accent-soft: #f7ece2; --tint: #fbf8f5; }
body[data-site="maths-help"]           { --accent: #1b4f9c; --accent-dark: #11366d; --accent-soft: #e7eef8; --tint: #f7f9fc; }

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { font-size: 16px; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--sans);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
img, svg { max-width: 100%; height: auto; }
a { color: var(--accent); text-decoration: underline; text-underline-offset: 2px; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }
button { font: inherit; cursor: pointer; }
input, select, textarea { font: inherit; color: inherit; }

/* ---------- Layout ---------- */
.shell {
  max-width: 880px;
  margin: 0 auto;
  padding: 0 16px;
}
.shell-narrow {
  max-width: 760px;
  margin: 0 auto;
}
.shell-wide {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 16px;
}

/* ---------- Header ---------- */
header.site {
  background: var(--bg);
  border-bottom: 1px solid var(--line);
  padding: 14px 0;
  position: sticky;
  top: 0;
  z-index: 50;
}
header.site .shell {
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px; flex-wrap: wrap;
}
header.site .brand { display: inline-flex; align-items: center; line-height: 1; text-decoration: none; color: var(--accent); }
header.site .brand:hover { text-decoration: none; }
header.site .brand svg.wordmark { height: 28px; width: auto; }
header.site nav.main {
  flex: 1;
  display: flex;
  justify-content: center;
}
header.site nav.main ul {
  list-style: none; margin: 0; padding: 0;
  display: flex; gap: 4px; flex-wrap: wrap;
}
header.site nav.main a {
  color: var(--ink-soft);
  font-size: 0.88rem;
  font-weight: 500;
  text-decoration: none;
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  transition: background 0.12s, color 0.12s;
}
header.site nav.main a:hover {
  color: var(--accent);
  background: var(--accent-soft);
}
header.site .cta {
  display: inline-flex; align-items: center; gap: 6px;
  background: var(--accent);
  color: #fff;
  font-size: 0.86rem;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  text-decoration: none;
  border: 0;
  white-space: nowrap;
}
header.site .cta:hover { background: var(--accent-dark); text-decoration: none; }
header.site .cta svg { width: 14px; height: 14px; }
@media (max-width: 720px) {
  header.site .shell { gap: 10px; }
  header.site nav.main { order: 3; flex-basis: 100%; justify-content: flex-start; overflow-x: auto; }
  header.site nav.main ul { flex-wrap: nowrap; }
  header.site nav.main a { font-size: 0.82rem; padding: 6px 8px; }
  header.site .cta { padding: 7px 12px; font-size: 0.82rem; }
}

/* ---------- Main + crumbs + headings ---------- */
main.shell { padding-top: 18px; padding-bottom: 32px; }

.crumbs {
  font-size: 0.8rem; color: var(--ink-faint);
  margin: 0 0 10px;
}
.crumbs a { color: var(--ink-faint); text-decoration: none; }
.crumbs a:hover { color: var(--accent); text-decoration: underline; }
.crumbs .sep { display: inline-block; padding: 0 6px; color: var(--line-strong); }
.crumbs span[aria-current] { color: var(--ink); }

h1 {
  font-family: var(--sans);
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.012em;
  line-height: 1.2;
  margin: 4px 0 8px;
  color: var(--ink);
}
h2 {
  font-family: var(--sans);
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: -0.005em;
  margin: 28px 0 10px;
  color: var(--ink);
}
h3 {
  font-family: var(--sans);
  font-size: 0.95rem;
  font-weight: 600;
  margin: 18px 0 6px;
}
.lede {
  font-size: 0.95rem;
  color: var(--ink-soft);
  margin: 0 0 14px;
  max-width: 60ch;
}
.lede b { color: var(--ink); font-weight: 600; }

/* ---------- Calculator (the centre of every page) ---------- */
.calc {
  border: 1px solid var(--line);
  background: var(--bg);
  padding: 18px 20px 20px;
  margin: 14px 0 22px;
  border-radius: var(--radius);
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.04);
}
.calc + .calc { margin-top: 16px; }
.calc-title {
  font-family: var(--sans);
  font-size: 1.05rem;
  font-weight: 600;
  margin: 0 0 14px;
  color: var(--ink);
  letter-spacing: -0.01em;
}
.calc-title::before {
  content: "";
  display: inline-block;
  width: 4px;
  height: 16px;
  background: var(--accent);
  border-radius: 2px;
  margin-right: 8px;
  vertical-align: -2px;
}

.calc-grid { display: grid; grid-template-columns: 1fr; gap: 10px; }
.calc-row { display: grid; grid-template-columns: minmax(120px, 0.6fr) 1fr; align-items: center; gap: 12px; }
.calc-row label {
  font-size: 0.9rem; color: var(--ink-soft); font-weight: 500;
}
.calc-row input[type="number"],
.calc-row input[type="date"],
.calc-row input[type="text"],
.calc-row select {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--line-strong);
  background: var(--bg);
  font-variant-numeric: tabular-nums slashed-zero;
  font-size: 0.96rem;
  border-radius: var(--radius-sm);
}
.calc-row input:focus, .calc-row select:focus {
  outline: 0;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
.calc-row input[type="checkbox"] { width: auto; accent-color: var(--accent); }
.calc-row .checkbox-row { grid-column: 1 / -1; display: flex; align-items: center; gap: 8px; font-size: 0.9rem; color: var(--ink-soft); cursor: pointer; }
.calc-row .checkbox-row input { margin: 0; }
@media (max-width: 560px) {
  .calc-row { grid-template-columns: 1fr; gap: 4px; }
  .calc-row label { font-size: 0.84rem; }
}

/* Scenario chips — compact, no label */
.chips {
  display: flex; flex-wrap: wrap; gap: 6px;
  margin: 0 0 12px;
}
.chip {
  appearance: none;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  color: var(--ink-soft);
  /* 8px vertical padding to keep chip ≥32px tall — meets mobile tap-target guidance */
  padding: 8px 12px;
  font-size: 0.82rem;
  font-weight: 500;
  border-radius: 999px;
  font-variant-numeric: tabular-nums;
  line-height: 1.3;
  text-align: left;
}
.chip:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
}
.chip:active { transform: translateY(1px); }
.chip[aria-pressed="true"] {
  border-color: var(--accent);
  background: var(--accent);
  color: #fff;
}

/* Result panel */
.calc-result {
  margin-top: 14px;
  padding: 14px 16px;
  background: var(--accent-soft);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: start;
  gap: 12px;
  min-height: 52px;
}
.calc-result.is-empty { color: var(--ink-faint); background: var(--bg-soft); border-left-color: var(--line); font-size: 0.88rem; }
.calc-result .result-body { min-width: 0; }
.calc-result .num {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(1.75rem, 1.6vw + 1.3rem, 2.4rem);
  font-variant-numeric: tabular-nums slashed-zero;
  font-feature-settings: "tnum" 1, "ss01" 1;
  color: var(--accent);
  line-height: 1.05;
  letter-spacing: -0.025em;
  display: inline-block;
}
.calc-result .work {
  display: block;
  margin-top: 8px;
  padding-top: 8px;
  border-top: 1px dashed var(--line);
  color: var(--ink-soft);
  font-size: 0.83rem;
  line-height: 1.5;
}
.calc-result .work b { color: var(--ink); font-weight: 600; }
.calc-result .crosslink {
  display: block;
  margin-top: 8px;
  font-size: 0.82rem;
}
.calc-result .crosslink a { color: var(--accent); }

.copy-link {
  flex-shrink: 0;
  appearance: none;
  background: var(--bg);
  border: 1px solid var(--line-strong);
  color: var(--ink-soft);
  font-size: 0.76rem;
  font-weight: 500;
  padding: 5px 9px 5px 8px;
  display: inline-flex; align-items: center; gap: 5px;
  border-radius: 4px;
  white-space: nowrap;
}
.copy-link:hover { color: var(--accent); border-color: var(--accent); }
.copy-link svg { width: 12px; height: 12px; }
.copy-link.copied { color: var(--accent); border-color: var(--accent); background: var(--accent-soft); }
@media (max-width: 560px) {
  .calc-result { grid-template-columns: 1fr; }
}

/* ---------- Below-calc content ---------- */
.intro p { margin: 10px 0; font-size: 0.95rem; color: var(--ink-soft); line-height: 1.6; max-width: 60ch; }
.intro p:first-child { margin-top: 0; }

.examples {
  margin: 6px 0 22px;
  border-top: 1px solid var(--line);
}
.examples-title {
  font-size: 0.92rem; font-weight: 600;
  color: var(--ink); margin: 14px 0 6px;
  letter-spacing: -0.005em;
}
.example {
  padding: 8px 0;
  border-bottom: 1px solid var(--line);
  font-size: 0.9rem;
  color: var(--ink-soft);
  line-height: 1.5;
}
.example b { color: var(--ink); font-weight: 600; font-variant-numeric: tabular-nums; }

.method-note {
  margin: 14px 0 22px;
  padding: 10px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  font-size: 0.86rem;
  color: var(--ink-soft);
  line-height: 1.5;
}
.method-note b { color: var(--ink); font-weight: 600; }
.method-note ol, .method-note ul { margin: 8px 0 6px 1.5em; padding: 0; }
.method-note ol li, .method-note ul li { margin: 2px 0; }
.method-note p { margin: 6px 0; }

/* Spotlight cross-calc card — for intent-redirected queries (e.g. salary
   queries on /percent-change/increase/ link to /tax/salary-increase/). */
.spotlight-card {
  margin: 18px 0 22px;
  padding: 14px 16px;
  border: 1px solid var(--accent);
  border-left: 4px solid var(--accent);
  background: var(--surface);
  border-radius: 4px;
}
.spotlight-label {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-soft);
  margin-bottom: 4px;
}
.spotlight-link {
  font-size: 1.05rem;
  color: var(--accent);
  text-decoration: none;
}
.spotlight-link:hover { text-decoration: underline; }
.spotlight-blurb {
  font-size: 0.88rem;
  color: var(--ink-soft);
  margin-top: 4px;
  line-height: 1.4;
}

/* Visible Updated stamp on YMYL pages — small, muted, but unmistakably present. */
.updated {
  margin: 8px 0 14px;
  font-size: 0.84rem;
  color: var(--ink-soft);
}
.updated b { color: var(--ink); font-weight: 600; }

.related-row {
  margin: 14px 0 22px;
  display: flex; flex-wrap: wrap; gap: 6px 14px;
  font-size: 0.88rem;
}
.related-row .label {
  color: var(--ink-faint); font-weight: 500; margin-right: 4px;
}
.related-row a { color: var(--ink); text-decoration: none; border-bottom: 1px solid var(--line-strong); padding-bottom: 1px; }
.related-row a:hover { color: var(--accent); border-bottom-color: var(--accent); }

.sources {
  margin: 18px 0 0;
  font-size: 0.78rem;
  color: var(--ink-faint);
  line-height: 1.5;
}
.sources b { color: var(--ink-soft); }
.sources a { color: var(--ink-soft); }

/* ---------- Hub list (categories) ---------- */
.hub-list {
  list-style: none; padding: 0; margin: 8px 0 24px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  border-top: 1px solid var(--line);
}
@media (min-width: 560px) {
  .hub-list { grid-template-columns: 1fr 1fr; gap: 0 24px; border-top: 0; }
}
.hub-list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--line);
}
.hub-list a {
  display: block;
  font-weight: 600;
  color: var(--ink);
  text-decoration: none;
  font-size: 0.95rem;
  letter-spacing: -0.005em;
}
.hub-list a:hover { color: var(--accent); }
.hub-list .desc {
  display: block;
  font-size: 0.82rem;
  color: var(--ink-faint);
  font-weight: 400;
  margin-top: 2px;
}

/* "Featured" — the most-popular block on home, before the full category list */
.featured h2 { margin-top: 0; }
.featured .hub-list a { font-size: 1rem; }

/* ---------- Tables ---------- */
table.bands {
  width: 100%; border-collapse: collapse; margin: 12px 0; font-size: 0.9rem;
  font-variant-numeric: tabular-nums;
}
table.bands th, table.bands td {
  padding: 8px 10px;
  border-bottom: 1px solid var(--line);
  text-align: left;
}
table.bands th { font-weight: 600; color: var(--ink); border-bottom: 1.5px solid var(--ink); }

/* ---------- FAQ ---------- */
.faq { margin: 24px 0; }
.faq h2 { margin-top: 0; }
.faq details {
  border-bottom: 1px solid var(--line);
  padding: 12px 0;
}
.faq details:first-of-type { border-top: 1px solid var(--line); }
.faq summary {
  cursor: pointer;
  font-weight: 500;
  font-size: 0.94rem;
  list-style: none;
  display: flex; align-items: flex-start; gap: 12px;
  color: var(--ink);
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+";
  margin-left: auto; flex-shrink: 0;
  color: var(--ink-faint); font-weight: 400;
  font-size: 1.1rem; line-height: 1;
}
.faq details[open] summary { margin-bottom: 8px; }
.faq details[open] summary::after { content: "−"; color: var(--accent); }
.faq details > div { font-size: 0.9rem; color: var(--ink-soft); line-height: 1.55; }

/* ---------- AdSense slots ---------- */
.ad-slot {
  margin: 22px 0;
  min-height: 250px;  /* reserve typical AdSense medium-rectangle to prevent CLS */
  background: var(--bg-soft);
  border: 1px solid var(--line);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.7rem;
  color: var(--ink-faint);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  position: relative;
}
.ad-slot::before {
  content: "Advertisement";
  position: absolute; top: 5px; left: 8px;
  font-size: 0.6rem; color: var(--ink-faint);
}
.ad-slot[data-loaded="1"]::before { content: ""; }

/* ---------- Recents — small block, only shown when populated ---------- */
.recents { display: none; margin: 24px 0; padding: 12px 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.recents .label {
  font-size: 0.88rem; font-weight: 600;
  color: var(--ink); margin-bottom: 6px;
}
.recents .recent-list { display: grid; gap: 4px; }
.recents .recent-item {
  display: flex; align-items: baseline; gap: 10px;
  padding: 4px 0;
  font-size: 0.86rem;
  text-decoration: none;
  color: var(--ink);
}
.recents .recent-item:hover .recent-name { color: var(--accent); }
.recents .recent-name { font-weight: 500; flex-shrink: 0; }
.recents .recent-meta { color: var(--ink-faint); font-size: 0.8rem; font-variant-numeric: tabular-nums; }
.recents .recent-clear {
  appearance: none; background: transparent; border: 0;
  color: var(--ink-faint); font-size: 0.76rem;
  padding: 6px 0 0;
  text-decoration: underline;
}
.recents .recent-clear:hover { color: var(--accent); }

/* ---------- Footer (multi-column) ---------- */
footer.site {
  margin-top: 48px;
  padding: 36px 0 28px;
  background: var(--tint);
  border-top: 1px solid var(--line);
  font-size: 0.86rem;
  color: var(--ink-soft);
}
footer.site .footer-cols {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 28px;
  margin-bottom: 28px;
}
footer.site .footer-brand .wordmark { height: 24px; width: auto; color: var(--accent); margin-bottom: 10px; }
footer.site .footer-brand p {
  font-size: 0.84rem;
  color: var(--ink-faint);
  line-height: 1.55;
  max-width: 36ch;
  margin: 0 0 14px;
}
footer.site .footer-col h4 {
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink);
  margin: 0 0 12px;
}
footer.site .footer-col ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}
footer.site .footer-col a {
  color: var(--ink-soft);
  text-decoration: none;
  font-size: 0.86rem;
}
footer.site .footer-col a:hover { color: var(--accent); text-decoration: underline; }
footer.site .footer-bottom {
  padding-top: 20px;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  align-items: baseline;
  justify-content: space-between;
}
footer.site .reviewer {
  font-size: 0.78rem; color: var(--ink-faint); line-height: 1.5;
  max-width: 80ch;
  margin: 0 0 12px;
}
footer.site .reviewer a { color: var(--ink-soft); }
footer.site .sister {
  font-size: 0.82rem; color: var(--ink-faint);
}
footer.site .sister b { color: var(--ink-soft); font-weight: 600; }
footer.site .sister a { color: var(--ink-soft); text-decoration: none; }
footer.site .sister a:hover { color: var(--accent); text-decoration: underline; }
footer.site .meta { font-size: 0.76rem; color: var(--ink-faint); }
footer.site .meta a { color: var(--ink-faint); }
@media (max-width: 760px) {
  footer.site .footer-cols { grid-template-columns: 1fr 1fr; gap: 22px; }
  footer.site .footer-brand { grid-column: 1 / -1; }
}
@media (max-width: 460px) {
  footer.site .footer-cols { grid-template-columns: 1fr; }
}

/* ---------- Home theme: hero, popular grid, guides, glossary, category chips ---------- */

/* Hero */
.hero {
  background: var(--tint);
  border-bottom: 1px solid var(--line);
  padding: 36px 0 32px;
  margin: 0 0 28px;
}
.hero .shell-wide {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
  gap: 36px;
  align-items: center;
}
.hero-copy { min-width: 0; }
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--accent-soft);
  color: var(--accent-dark);
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 5px 10px;
  border-radius: 999px;
  margin-bottom: 14px;
}
.hero-badge::before {
  content: "";
  display: inline-block;
  width: 6px; height: 6px;
  background: var(--accent);
  border-radius: 50%;
}
.hero h1 {
  font-size: clamp(1.85rem, 1.4vw + 1.5rem, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.022em;
  line-height: 1.1;
  margin: 0 0 12px;
  color: var(--ink);
}
.hero h1 .accent { color: var(--accent); }
.hero .lede {
  font-size: 1rem;
  color: var(--ink-soft);
  line-height: 1.55;
  max-width: 52ch;
  margin: 0 0 18px;
}
.trust-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 22px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.trust-strip li {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.82rem;
  color: var(--ink-soft);
  font-weight: 500;
}
.trust-strip svg {
  width: 14px; height: 14px;
  color: var(--accent);
  flex-shrink: 0;
}
.hero-illo {
  display: flex;
  align-items: center;
  justify-content: center;
}
.hero-illo svg {
  width: 100%;
  max-width: 320px;
  height: auto;
  color: var(--accent);
}
@media (max-width: 760px) {
  .hero { padding: 24px 0 22px; }
  .hero .shell-wide { grid-template-columns: 1fr; gap: 20px; }
  .hero-illo { order: -1; max-height: 180px; }
  .hero-illo svg { max-width: 180px; max-height: 180px; }
  .hero h1 { font-size: 1.7rem; }
}

/* Popular calculators icon grid */
.popular {
  margin: 28px 0;
}
.popular > h2,
.guides > h2,
.glossary > h2,
.cat-chips-block > h2 {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.012em;
  margin: 0 0 4px;
  color: var(--ink);
}
.section-sub {
  font-size: 0.92rem;
  color: var(--ink-soft);
  margin: 0 0 18px;
}
.popular-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 12px;
}
.popular-card {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg);
  text-decoration: none;
  color: var(--ink);
  transition: border-color 0.12s, background 0.12s, transform 0.12s;
}
.popular-card:hover {
  border-color: var(--accent);
  background: var(--accent-soft);
  text-decoration: none;
  transform: translateY(-1px);
}
.popular-card .icon {
  flex-shrink: 0;
  width: 36px; height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: var(--accent-soft);
  color: var(--accent);
}
.popular-card .icon svg { width: 20px; height: 20px; }
.popular-card .body { min-width: 0; }
.popular-card .name {
  display: block;
  font-weight: 600;
  font-size: 0.95rem;
  line-height: 1.25;
  letter-spacing: -0.005em;
}
.popular-card .desc {
  display: block;
  font-size: 0.8rem;
  color: var(--ink-faint);
  margin-top: 3px;
  line-height: 1.4;
}

/* Guides & examples card grid */
.guides { margin: 36px 0; }
.guides-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 14px;
}
.guides-card {
  position: relative;
  display: block;
  padding: 18px 16px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg);
  text-decoration: none;
  color: var(--ink);
  overflow: hidden;
}
.guides-card:hover { border-color: var(--accent); text-decoration: none; }
.guides-card .tile {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 110px;
  background: var(--accent-soft);
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  color: var(--accent);
}
.guides-card .tile svg { width: 56px; height: 56px; }
.guides-card .name {
  display: block;
  font-weight: 600;
  font-size: 0.98rem;
  letter-spacing: -0.005em;
}
.guides-card .desc {
  display: block;
  font-size: 0.84rem;
  color: var(--ink-faint);
  margin-top: 4px;
  line-height: 1.45;
}

/* Formulas & glossary */
.glossary { margin: 36px 0; }
.glossary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 8px 24px;
}
.glossary-term {
  padding: 10px 0;
  border-bottom: 1px solid var(--line);
}
.glossary-term .term {
  display: block;
  font-weight: 600;
  font-size: 0.92rem;
  color: var(--ink);
  margin-bottom: 2px;
}
.glossary-term .def {
  display: block;
  font-size: 0.85rem;
  color: var(--ink-soft);
  line-height: 1.5;
}
.glossary-term .def code {
  font-family: ui-monospace, 'Cascadia Code', 'Menlo', monospace;
  font-size: 0.9em;
  background: var(--bg-soft);
  padding: 1px 5px;
  border-radius: 3px;
  font-variant-numeric: tabular-nums;
}

/* Category chips strip */
.cat-chips-block { margin: 36px 0; }
.cat-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.cat-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-dark);
  font-size: 0.86rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  transition: background 0.12s, color 0.12s, border-color 0.12s;
}
.cat-chip:hover {
  background: var(--accent);
  color: #fff;
  text-decoration: none;
}
.cat-chip .desc {
  color: var(--ink-faint);
  font-weight: 400;
  font-size: 0.8rem;
}
.cat-chip:hover .desc { color: rgba(255,255,255,0.85); }

/* ---------- Body prose ---------- */
main.shell p { margin: 10px 0; line-height: 1.6; max-width: 60ch; }
main.shell ul, main.shell ol { padding-left: 1.2em; }
main.shell ul li, main.shell ol li { margin: 4px 0; line-height: 1.55; }
main.shell code { font-family: ui-monospace, 'Cascadia Code', 'Menlo', monospace; font-size: 0.88em; background: var(--bg-soft); padding: 1px 5px; border: 1px solid var(--line); border-radius: 3px; }

/* ---------- Misc ---------- */
.tnum { font-variant-numeric: tabular-nums slashed-zero; }
.visually-hidden {
  position: absolute !important; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0);
  white-space: nowrap; border: 0;
}
@keyframes resultPop {
  0% { transform: translateY(2px); opacity: 0.65; }
  100% { transform: translateY(0); opacity: 1; }
}
.calc-result.result-pop .num { animation: resultPop 0.28s ease-out; }
@media (prefers-reduced-motion: reduce) {
  .calc-result.result-pop .num { animation: none; }
}