:root {
  --accent: #2563eb;
  --accent-soft: #eff6ff;
  --accent-deep: #1e40af;
  --ink: #17191c;
  --body: #33373d;
  --muted: #6b7280;
  --line: #e6e8ec;
  --bg: #ffffff;
  --surface: #fafbfc;
  --heading-font: 'Space Grotesk', system-ui, sans-serif;
  --body-font: 'Newsreader', Georgia, serif;
  --measure: 44rem;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(16,24,40,.04), 0 12px 30px -12px rgba(16,24,40,.12);
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 90px; }
body {
  margin: 0; background: var(--bg); color: var(--body);
  font: 1.075rem/1.75 var(--body-font);
  -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility;
}
h1, h2, h3, h4 { font-family: var(--heading-font); color: var(--ink);
  line-height: 1.18; letter-spacing: -.01em; }
h1 { font-size: clamp(2rem, 1.3rem + 3vw, 3.1rem); font-weight: 700; margin: 0 0 .4em; }
h2 { font-size: clamp(1.4rem, 1.1rem + 1.2vw, 1.85rem); font-weight: 600; margin: 2.2em 0 .55em; }
h3 { font-size: 1.2rem; font-weight: 600; margin: 1.6em 0 .3em; }
p { margin: 0 0 1.1em; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 2px; }
strong { color: var(--ink); }

.wrap { max-width: 72rem; margin: 0 auto; padding: 0 24px; }

/* ---------- header ---------- */
.site-header { position: sticky; top: 0; z-index: 10; background: rgba(255,255,255,.9);
  backdrop-filter: saturate(1.5) blur(12px); border-bottom: 1px solid var(--line); }
.header-inner { display: flex; align-items: center; justify-content: space-between;
  gap: 14px; padding: 12px 24px; position: relative; }
.brand { display: inline-flex; align-items: center; gap: 11px; color: var(--ink); }
.brand:hover { text-decoration: none; }
.brand-emblem { display: grid; place-items: center; width: 37px; height: 37px;
  border-radius: 10px; background: var(--accent-soft); color: var(--accent);
  border: 1.5px solid color-mix(in srgb, var(--accent) 22%, transparent); }
.brand-emblem svg { width: 20px; height: 20px; }
.brand-name { font-family: var(--heading-font); font-weight: 700; font-size: 1.24rem;
  letter-spacing: -.015em; line-height: 1; }
.nav-burger { display: none; cursor: pointer; padding: 8px; border-radius: 9px;
  color: var(--ink); border: 1px solid var(--line); background: #fff; }
.nav-burger svg { width: 22px; height: 22px; display: block; }
.topnav { display: flex; gap: 2px; align-items: center; }
.topnav a { color: var(--body); font-size: .96rem; font-weight: 500;
  padding: 8px 13px; border-radius: 9px; }
.topnav a:hover { color: var(--accent); background: var(--accent-soft); text-decoration: none; }

@media (max-width: 680px) {
  .nav-burger { display: inline-flex; }
  .topnav { display: none; position: absolute; top: calc(100% + 8px); right: 24px;
    left: 24px; flex-direction: column; align-items: stretch; gap: 2px; padding: 8px;
    background: #fff; border: 1px solid var(--line); border-radius: 14px;
    box-shadow: var(--shadow); }
  .nav-toggle:checked ~ .topnav { display: flex; }
  .topnav a { padding: 11px 14px; font-size: 1rem; }
}

/* ---------- hero (pillar) ---------- */
.hero { position: relative; overflow: hidden; background:
    radial-gradient(120% 120% at 100% 0%, var(--accent-soft) 0%, transparent 55%),
    linear-gradient(180deg, var(--surface), #fff);
  border-bottom: 1px solid var(--line); }
.hero-art { position: absolute; right: -30px; top: 50%; transform: translateY(-50%);
  width: 360px; height: 360px; color: var(--accent); opacity: .07;
  pointer-events: none; }
.hero-art svg { width: 100%; height: 100%; stroke-width: .9; }
.hero-inner { position: relative; padding: 68px 24px 56px; max-width: 40rem; }
.kicker { text-transform: uppercase; letter-spacing: .13em; font-size: .78rem;
  font-weight: 700; color: var(--accent); margin: 0 0 .9em; }
.hero-lead { font-size: 1.28rem; line-height: 1.6; color: #3c4149; max-width: 38rem; }
.hero-meta { margin-top: 1.4em; font-size: .92rem; color: var(--muted);
  border-top: 1px solid var(--line); padding-top: 1em; display: inline-block; }

/* ---------- trust chips ---------- */
.trust { list-style: none; display: flex; flex-wrap: wrap; gap: 8px 10px;
  padding: 0; margin: 1.5em 0 0; }
.trust li { display: inline-flex; align-items: center; gap: 6px; font-size: .84rem;
  font-weight: 600; color: var(--accent-deep); background: color-mix(in srgb, var(--accent-soft) 70%, #fff);
  border: 1px solid color-mix(in srgb, var(--accent) 16%, transparent);
  padding: 5px 12px 5px 10px; border-radius: 999px; }
.trust svg { width: 14px; height: 14px; color: var(--accent); }
.article-head .trust { margin-top: 1.2em; }
@media (max-width: 720px) {
  .hero-art { width: 230px; right: -50px; opacity: .06; }
}

/* ---------- layout ---------- */
.page { padding: 44px 24px 24px; }
.prose { max-width: var(--measure); margin: 0 auto; }
.prose.narrow { max-width: 40rem; }
.section { scroll-margin-top: 90px; }
.section h2 { position: relative; padding-top: .2em; }
.checklist { list-style: none; padding-left: 0; }
.checklist li { position: relative; padding-left: 1.9em; margin: .5em 0; }
.checklist li::before { content: ""; position: absolute; left: 0; top: .62em;
  width: 12px; height: 7px; border-left: 2.5px solid var(--accent);
  border-bottom: 2.5px solid var(--accent); transform: rotate(-45deg); }
.prose ul:not(.checklist) { padding-left: 1.2em; }
.prose ul:not(.checklist) li { margin: .4em 0; }
.prose ul:not(.checklist) li::marker { color: var(--accent); }

/* ---------- article header ---------- */
.article-page { padding-top: 34px; }
.breadcrumbs { font-size: .86rem; color: var(--muted); margin-bottom: 1.6em; }
.breadcrumbs a { color: var(--muted); }
.breadcrumbs .current { color: var(--ink); }
.breadcrumbs span { margin: 0 .45em; }
.article-head { margin-bottom: 1.6em; }
.byline { display: flex; align-items: center; gap: 9px; font-size: .92rem;
  color: var(--muted); margin: 1em 0 0; }
.byline-mark { display: grid; place-items: center; width: 26px; height: 26px;
  border-radius: 50%; background: var(--accent-soft); color: var(--accent-deep);
  font-family: var(--heading-font); font-weight: 700; font-size: .72rem; }
.byline .dot { opacity: .5; }
.lead { font-size: 1.24rem; line-height: 1.62; color: #3a3f47; }
.article-body > .lead:first-of-type::first-letter {
  font-family: var(--heading-font); font-weight: 700; float: left; font-size: 3.3rem;
  line-height: .82; padding: .05em .12em 0 0; color: var(--accent); }

/* ---------- key takeaways ---------- */
.takeaways { background: var(--accent-soft); border: 1px solid var(--line);
  border-left: 4px solid var(--accent); border-radius: var(--radius);
  padding: 20px 24px 22px; margin: 2em 0; }
.takeaways-title { font-size: .82rem; text-transform: uppercase; letter-spacing: .1em;
  color: var(--accent-deep); margin: 0 0 .7em; }
.takeaways ul { margin: 0; padding-left: 1.2em; }
.takeaways li { margin: .45em 0; color: var(--ink); }
.takeaways li::marker { color: var(--accent); }

/* ---------- table of contents ---------- */
.toc { border: 1px solid var(--line); border-radius: var(--radius);
  padding: 16px 22px 18px; margin: 2em 0; background: var(--surface); }
.toc-title { font-size: .78rem; text-transform: uppercase; letter-spacing: .1em;
  color: var(--muted); margin: 0 0 .6em; font-weight: 700; }
.toc ol { margin: 0; padding-left: 1.3em; }
.toc li { margin: .3em 0; }
.toc a { color: var(--body); }
.toc a:hover { color: var(--accent); }

/* ---------- FAQ ---------- */
.faq { margin-top: 2.6em; }
.faq-item { border-top: 1px solid var(--line); padding: 4px 0; }
.faq-item summary { cursor: pointer; list-style: none; font-family: var(--heading-font);
  font-weight: 600; font-size: 1.08rem; color: var(--ink); padding: 14px 34px 14px 0;
  position: relative; }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; position: absolute; right: 4px; top: 10px;
  font-size: 1.4rem; color: var(--accent); font-weight: 400; }
.faq-item[open] summary::after { content: "\2013"; }
.faq-item p { margin: 0 0 16px; }

/* ---------- editorial note ---------- */
.editorial-note { margin-top: 2.8em; padding: 18px 22px; background: var(--surface);
  border: 1px solid var(--line); border-radius: var(--radius); font-size: .95rem;
  color: var(--muted); }

/* ---------- cards (cluster / related) ---------- */
.cluster, .related { max-width: 72rem; margin: 3.4em auto 0; }
.cluster-head { max-width: var(--measure); margin: 0 auto 1.4em; }
.cluster-head p { color: var(--muted); margin: .2em 0 0; }
.card-list { list-style: none; padding: 0; margin: 0; display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 18px; }
.card { position: relative; background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius); padding: 22px 22px 20px; transition: .18s ease;
  display: flex; flex-direction: column; }
.card:hover { border-color: var(--accent); box-shadow: var(--shadow); transform: translateY(-2px); }
.card-num { font-family: var(--heading-font); font-weight: 700; font-size: .8rem;
  color: var(--accent); letter-spacing: .05em; }
.card h3 { margin: .3em 0 .35em; font-size: 1.14rem; line-height: 1.3; }
.card h3 a { color: var(--ink); }
.card h3 a:hover { color: var(--accent); text-decoration: none; }
.card p { color: var(--muted); font-size: .94rem; margin: 0 0 1em; flex: 1; }
.card-go { color: var(--accent); font-weight: 600; font-size: .9rem; }

/* ---------- contact form ---------- */
.contact-form { display: grid; gap: 18px; margin-top: 1.8em; max-width: 34rem; }
.field { display: grid; gap: 6px; }
.field label { font-family: var(--heading-font); font-weight: 600; font-size: .95rem; color: var(--ink); }
.contact-form input, .contact-form textarea { font: inherit; padding: 12px 14px;
  border: 1px solid var(--line); border-radius: 10px; background: #fff; color: var(--ink);
  width: 100%; transition: border-color .15s, box-shadow .15s; }
.contact-form input:focus, .contact-form textarea:focus { outline: none;
  border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.contact-form textarea { resize: vertical; }
.field-error { margin: 0; color: #b91c1c; font-size: .86rem; }
.contact-form button { justify-self: start; font: 600 1rem var(--heading-font);
  padding: 12px 26px; border: 0; border-radius: 10px; cursor: pointer; color: #fff;
  background: var(--accent); transition: filter .15s, transform .05s; }
.contact-form button:hover { filter: brightness(1.07); }
.contact-form button:active { transform: translateY(1px); }
.contact-form button:disabled { opacity: .6; cursor: default; }
.form-status { margin: 0; font-weight: 600; }
.form-status.ok { color: var(--accent-deep); }
.form-status.err { color: #b91c1c; }
.hp { position: absolute; left: -9999px; width: 1px; height: 1px; opacity: 0; }

/* ---------- footer ---------- */
.site-footer { margin-top: 72px; background: var(--surface); border-top: 1px solid var(--line); }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr; gap: 32px;
  padding: 48px 24px 32px; }
.footer-brand .brand { margin-bottom: 12px; }
.footer-tagline { color: var(--muted); font-size: .94rem; margin: 0; max-width: 26rem; }
.footer-col h4 { font-size: .78rem; text-transform: uppercase; letter-spacing: .1em;
  color: var(--muted); margin: 4px 0 .8em; }
.footer-col ul { list-style: none; padding: 0; margin: 0; }
.footer-col li { margin: .5em 0; }
.footer-col a { color: var(--body); font-size: .95rem; }
.footer-col a:hover { color: var(--accent); }
.footer-legal { border-top: 1px solid var(--line); padding: 18px 24px 40px;
  color: var(--muted); font-size: .86rem; }
.footer-legal p { margin: 0; }

@media (max-width: 720px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
  .hero-inner { padding: 46px 24px 40px; }
  .article-body > .lead:first-of-type::first-letter { font-size: 2.8rem; }
}