:root {
  --bg: #ffffff;
  --bg-alt: #f7f9fc;
  --surface: #ffffff;
  --text: #070c1c;
  --text-secondary: #6f7a8e;
  --border: #e3e8f0;
  --accent: #3f73ed;
  --accent-soft: #eaf1ff;
  --success: #2ea86c;
  --success-soft: #e9f8f1;
  --warning: #f0a12a;
  --warning-soft: #fff3da;
  --shadow: 0 1px 3px rgba(16,24,40,.06), 0 16px 42px rgba(16,24,40,.08);
  --maxw: 1120px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0a0d14;
    --bg-alt: #0e131c;
    --surface: #151922;
    --text: #f8fafc;
    --text-secondary: #a7b0c0;
    --border: #313948;
    --accent: #5f8cff;
    --accent-soft: #22375f;
    --success: #49c987;
    --success-soft: #1d3a2d;
    --warning-soft: #3d3016;
    --shadow: 0 1px 3px rgba(0,0,0,.35), 0 16px 42px rgba(0,0,0,.34);
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.7 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: color-mix(in srgb, var(--bg) 90%, transparent);
  backdrop-filter: saturate(150%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav { height: 66px; display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; color: var(--text); white-space: nowrap; }
.brand:hover { text-decoration: none; }
.brand img { width: 32px; height: 32px; border-radius: 8px; }
.nav-links { display: flex; gap: 22px; align-items: center; }
.nav-links a { color: var(--text-secondary); font-size: 15px; font-weight: 550; }
.nav-links a:hover { color: var(--text); text-decoration: none; }
@media (max-width: 760px) { .nav-links { display: none; } }
.hero { padding: 74px 0 44px; background: linear-gradient(180deg, var(--bg) 0%, var(--bg-alt) 100%); }
.hero-grid { display: grid; grid-template-columns: 1fr .92fr; gap: 46px; align-items: center; }
@media (max-width: 940px) { .hero-grid { grid-template-columns: 1fr; } }
.eyebrow { color: var(--accent); font-size: 13px; font-weight: 750; letter-spacing: .04em; text-transform: uppercase; }
h1, h2, h3 { margin: 0; line-height: 1.12; letter-spacing: -.02em; }
h1 { font-size: clamp(38px, 6vw, 62px); margin-top: 14px; }
h2 { font-size: clamp(28px, 4vw, 40px); margin-top: 58px; }
h3 { font-size: 22px; margin-top: 28px; }
p { margin: 16px 0 0; color: var(--text-secondary); }
.lede { font-size: 20px; max-width: 690px; }
.meta { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 24px; color: var(--text-secondary); font-size: 14px; }
.tag { background: var(--accent-soft); color: var(--accent); border-radius: 999px; padding: 6px 12px; font-weight: 650; }
.hero-img { aspect-ratio: 16 / 9; overflow: hidden; border: 1px solid var(--border); border-radius: 20px; background: var(--surface); box-shadow: var(--shadow); }
.hero-img img { width: 100%; height: 100%; object-fit: cover; object-position: center; }
/* One centred column. The horizontal padding has to be repeated here: this
   shorthand would otherwise cancel the 24px gutter .wrap sets, leaving article
   text flush against both screen edges on a phone. */
.layout { max-width: 880px; padding: 54px 24px 84px; }
article { max-width: none; min-width: 0; }
article ul, article ol { color: var(--text-secondary); padding-left: 24px; }
article li { margin: 10px 0; }
strong { color: var(--text); }
.summary { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin: 34px 0; }
@media (max-width: 760px) { .summary { grid-template-columns: 1fr; } }
.summary-card, .callout, .answer, .takeaways, .source-box, .end-cta {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow);
}
.summary-card { padding: 18px; }
.summary-card span { display: block; color: var(--accent); font-size: 13px; font-weight: 750; text-transform: uppercase; }
.summary-card b { display: block; margin-top: 8px; font-size: 18px; line-height: 1.3; }
.callout { padding: 20px; margin: 30px 0; background: var(--accent-soft); box-shadow: none; }
.callout p { color: var(--text); }
.timeline { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin-top: 24px; }
@media (max-width: 760px) { .timeline { grid-template-columns: 1fr; } }
.step { padding: 16px; background: var(--bg-alt); border: 1px solid var(--border); border-radius: 14px; }
.step span { color: var(--accent); font-weight: 800; font-size: 13px; }
.step b { display: block; margin-top: 8px; }
.source-box { padding: 20px; margin-top: 46px; }
.source-box h2 { margin-top: 0; font-size: 25px; }
.source-box ul { margin-bottom: 0; }
aside { position: sticky; top: 92px; align-self: start; }
/* Closing call to action, in place of the old sidebar's download button. */
.end-cta { padding: 26px; margin: 44px 0 0; text-align: center; }
.end-cta b { display: block; font-family: inherit; font-size: 20px; }
.end-cta p { margin: 10px 0 18px; }
.end-cta .btn { display: inline-block; }
.btn {
  display: inline-flex;
  justify-content: center;
  align-items: center;
  margin-top: 18px;
  background: var(--accent);
  color: #fff;
  border-radius: 12px;
  padding: 12px 18px;
  font-weight: 700;
}
.btn:hover { text-decoration: none; filter: brightness(1.06); }
.nav > .btn { margin-top: 0; }
.table-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: 16px; background: var(--surface); margin: 30px 0; }
table { width: 100%; border-collapse: collapse; min-width: 620px; }
th, td { padding: 14px 16px; border-bottom: 1px solid var(--border); text-align: left; }
th { color: var(--text-secondary); font-size: 13px; text-transform: uppercase; letter-spacing: .04em; }
tr:last-child td { border-bottom: 0; }
.meter { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; margin: 30px 0; }
@media (max-width: 760px) { .meter { grid-template-columns: 1fr; } }
.meter-card { background: var(--surface); border: 1px solid var(--border); border-radius: 16px; padding: 22px; }
.meter-card .big { font-size: 36px; line-height: 1; color: var(--text); font-weight: 800; margin-top: 8px; }
.article-figure { margin: 34px 0; }
.article-figure img { width: 100%; max-height: 720px; object-fit: contain; object-position: center; border: 1px solid var(--border); border-radius: 16px; background: var(--bg-alt); box-shadow: var(--shadow); }
.article-figure.phone-shot { max-width: 390px; margin-left: auto; margin-right: auto; }
.article-figure figcaption { margin-top: 10px; color: var(--text-secondary); font-size: 14px; text-align: center; }
.article-figure-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; margin: 30px 0; }
@media (max-width: 700px) { .article-figure-grid { grid-template-columns: 1fr; } }
.article-figure-grid .article-figure { margin: 0; }
/* The numbered marker is positioned rather than laid out as a grid column.
   A grid item would only hold together while every list item had exactly one
   child: loose text alongside a <b> becomes its own anonymous grid item and
   drops into the narrow marker column, one word per line. */
.method-list { margin: 24px 0; padding: 0; list-style: none; counter-reset: method; }
.method-list li { counter-increment: method; position: relative; padding-left: 46px; margin: 0 0 14px; min-height: 30px; }
.method-list li:last-child { margin-bottom: 0; }
.method-list li::before {
  content: counter(method);
  position: absolute;
  left: 0;
  top: 1px;
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 800;
}
.method-list b { color: var(--text); }
footer { border-top: 1px solid var(--border); background: var(--bg-alt); padding: 42px 0; color: var(--text-secondary); font-size: 14px; }

/* ---------- Answer block ---------- */
/* The short answer, above the fold, for people who came from a search result
   and want the fact rather than the essay. */
.answer { padding: 22px 24px; margin: 30px 0; background: var(--accent-soft); box-shadow: none; }
.answer h2, .answer h3 { margin-top: 0; font-size: 19px; }
.answer p:last-child { margin-bottom: 0; }
.answer p { color: var(--text); }

/* ---------- Key takeaways ---------- */
.takeaways { padding: 22px 24px; margin: 30px 0; }
.takeaways h2 { margin-top: 0; font-size: 19px; }
.takeaways ul { margin: 0; padding-left: 20px; }
.takeaways li { margin: 8px 0; }

/* ---------- FAQ ---------- */
.faq-list { margin: 24px 0 8px; display: grid; gap: 10px; }
details.faq {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px 20px;
}
details.faq > summary {
  cursor: pointer;
  font-weight: 700;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}
details.faq > summary::-webkit-details-marker { display: none; }
details.faq > summary::after {
  content: "+";
  color: var(--accent);
  font-weight: 700;
  flex: none;
}
details.faq[open] > summary::after { content: "–"; }
details.faq > p { margin: 12px 0 0; color: var(--text-secondary); }

/* ---------- Related reading ---------- */
.related { margin: 36px 0 0; padding-top: 24px; border-top: 1px solid var(--border); }
.related h2 { font-size: 19px; }
.related ul { margin: 0; padding-left: 20px; }
.related li { margin: 6px 0; }

/* ---------- Breadcrumb ---------- */
.crumbs { font-size: 13px; color: var(--text-secondary); margin-bottom: 10px; }
.crumbs a { color: var(--text-secondary); text-decoration: none; }
.crumbs a:hover { color: var(--accent); }