:root {
  color-scheme: light;
  --paper: #f8f9fb;
  --white: #ffffff;
  --ink: #262930;
  --accent: #b43832;
  --muted: #595c65;
  --line: #d8d9de;
  --wash: #fff0eb;
  --heading-font: "Trebuchet MS", "Segoe UI", sans-serif;
  --radius: 14px;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 17px;
  line-height: 1.7;
  color: var(--ink);
  background: var(--paper);
  accent-color: var(--accent);
  scrollbar-color: var(--muted) var(--paper);
}
* { box-sizing: border-box; }
body { margin: 0; }
[hidden] { display: none !important; }
::selection { color: var(--white); background: var(--accent); }
a { color: var(--accent); text-underline-offset: .22em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }
button, a { -webkit-tap-highlight-color: #b4383222; }
button { font: inherit; color: inherit; cursor: pointer; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 5px; border-radius: 3px; }
main:focus { outline: none; }
h1, h2, h3, p, figure { margin: 0; }
h1, h2 { font-family: var(--heading-font); font-weight: 700; text-wrap: balance; }
h1 { font-size: clamp(2.5rem, 5.5vw, 4.3rem); line-height: 1.1; letter-spacing: -.03em; max-width: 17ch; }
h2 { font-size: clamp(1.7rem, 3vw, 2.45rem); line-height: 1.2; letter-spacing: -.025em; }
h3 { font-size: 1.08rem; line-height: 1.4; font-weight: 650; }
p { max-width: 68ch; }
p + p { margin-top: 1em; }
img, svg { max-width: 100%; }
ul, ol { padding-left: 1.4em; }
li + li { margin-top: .65em; }
.wrap { width: min(1180px, calc(100% - 96px)); margin-inline: auto; }
.skip { position: fixed; top: 12px; left: 12px; padding: 12px 20px; z-index: 10; background: var(--white); transform: translateY(-170%); }
.skip:focus { transform: translateY(0); }
.site-header { border-bottom: 1px solid var(--line); }
.header-inner { display: flex; justify-content: space-between; align-items: center; gap: 28px; min-height: 96px; }
.brand { display: inline-flex; align-items: center; gap: 10px; min-height: 44px; font-size: 1.1rem; font-weight: 750; letter-spacing: -.03em; text-decoration: none; color: var(--ink); white-space: nowrap; }
.brand img { width: 36px; height: 36px; }
.site-nav { display: flex; flex-wrap: wrap; align-items: center; gap: 12px 28px; font-size: .9rem; }
.site-nav a { display: inline-flex; align-items: center; min-height: 44px; text-decoration: none; }
.site-nav a:hover, .site-nav [aria-current="page"] { text-decoration: underline; }
.menu-toggle { display: none; min-height: 44px; min-width: 64px; padding: 5px 12px; border: 1px solid var(--line); border-radius: 6px; background: transparent; }
.home-hero { display: grid; grid-template-columns: 1.15fr 1fr; align-items: center; gap: 9%; padding-block: 92px 100px; }
.home-intro { animation: settle .55s cubic-bezier(.16, 1, .3, 1); }
.home-intro > p { margin-top: 22px; }
.lede { font-size: clamp(1.12rem, 2vw, 1.3rem); line-height: 1.65; }
.button { display: inline-flex; justify-content: space-between; align-items: center; gap: 28px; min-height: 52px; margin-top: 30px; border-radius: 6px; padding: 13px 21px; background: var(--accent); color: var(--white); font-size: .94rem; font-weight: 650; text-decoration: none; transition: background-color .16s ease; }
.button:hover { background: var(--ink); }
.payment-figure { padding: 32px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--white); }
.payment-figure h2 { font-size: 1.6rem; max-width: 20ch; }
.payment-figure ol { list-style: none; margin: 26px 0 22px; padding: 0; }
.payment-figure li { position: relative; display: flex; align-items: flex-start; gap: 17px; padding-bottom: 26px; }
.payment-figure li + li { margin: 0; }
.payment-figure li:not(:last-child)::after { content: ""; position: absolute; left: 17px; top: 38px; bottom: 5px; border-left: 1px solid var(--accent); }
.payment-figure li:last-child { padding-bottom: 0; }
.diagram-number { display: grid; place-items: center; flex: 0 0 36px; height: 36px; border: 1px solid var(--accent); background: var(--wash); color: var(--accent); border-radius: 50%; font-size: .85rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.payment-figure strong { display: block; font-size: .98rem; }
.payment-figure li p { margin-top: 3px; font-size: .87rem; color: var(--muted); line-height: 1.55; }
figcaption { font-size: .84rem; line-height: 1.6; color: var(--muted); }
.payment-figure figcaption { border-top: 1px solid var(--line); padding-top: 17px; }
.learning-section { background: var(--white); border-block: 1px solid var(--line); padding-block: 76px; }
.path-layout { display: grid; grid-template-columns: .8fr 1.4fr; gap: 10%; }
.path-layout > div { align-self: start; }
.path-layout > div p { margin-top: 20px; }
.text-link { display: inline-flex; align-items: center; min-height: 44px; font-weight: 600; font-size: .94rem; }
.path-layout .text-link { margin-top: 22px; }
.learning-path { margin: 0; padding: 0; list-style: none; }
.learning-path li { display: grid; grid-template-columns: 35px 1fr 22px; gap: 16px; padding: 22px 0; border-top: 1px solid var(--line); transition: background-color .18s ease; }
.learning-path li:hover, .learning-path li:focus-within { background: var(--wash); }
.learning-path li:hover h3 a, .learning-path li:focus-within h3 a { color: var(--accent); text-decoration: underline; }
.learning-path li:first-child { padding-top: 0; border-top: 0; }
.learning-path li + li { margin: 0; }
.learning-path li:last-child { padding-bottom: 0; }
.path-number { padding-top: 11px; font-size: .8rem; font-variant-numeric: tabular-nums; color: var(--muted); }
.learning-path h3 a { display: inline-flex; align-items: center; min-height: 44px; color: var(--ink); text-decoration: none; }
.learning-path h3 a:hover { text-decoration: underline; }
.learning-path p { color: var(--muted); font-size: .94rem; }
.path-arrow { align-self: start; padding-top: 7px; color: var(--accent); transition: transform .18s ease; }
.learning-path li:hover .path-arrow, .learning-path li:focus-within .path-arrow { transform: translateX(2px); }
.home-reminder { max-width: 790px; padding-block: 76px; }
.home-reminder p { margin-top: 22px; }
.home-reminder .text-link { margin-top: 20px; }
.learn-section { background: var(--wash); padding-block: 70px; border-block: 1px solid var(--line); }
.learn-layout { display: grid; grid-template-columns: .9fr 1.1fr; gap: 10%; align-items: start; }
.learn-layout h2 { margin-bottom: 20px; }
.learn-layout .text-link { margin-top: 17px; }
.form-slot { min-width: 0; }
.ghl-form iframe { display: block; max-width: 100%; min-height: inherit; }
.form-placeholder { display: grid; min-height: 220px; place-content: center; padding: 30px; text-align: center; background: var(--paper); border: 1px solid var(--muted); border-radius: var(--radius); }
.form-placeholder p { font-size: 1.05rem; font-weight: 600; }
.form-placeholder small { display: block; margin-top: 8px; max-width: 30ch; color: var(--muted); }
.form-slot iframe { display: block; }
.breadcrumbs { padding-block: 26px; font-size: .82rem; color: var(--muted); }
.breadcrumbs ol { display: flex; flex-wrap: wrap; list-style: none; gap: 3px 12px; padding: 0; margin: 0; }
.breadcrumbs li + li { margin: 0; }
.breadcrumbs li + li::before { content: "/"; padding-right: 12px; color: var(--muted); }
.breadcrumbs a { display: inline-flex; align-items: center; min-height: 44px; }
.breadcrumbs [aria-current] { display: inline-flex; align-items: center; min-height: 44px; }
.home-breadcrumb { padding-block: 0; }
.page-intro { max-width: 880px; padding-block: 24px 52px; }
.page-intro h1 { max-width: 19ch; font-size: clamp(2.5rem, 5vw, 4.15rem); }
.page-intro .lede { margin-top: 28px; max-width: 62ch; }
.updated { margin-top: 20px; font-size: .8rem; color: var(--muted); }
.disclaimer { margin-top: 22px; font-size: .88rem; font-weight: 650; }
.article-layout { display: grid; grid-template-columns: 230px minmax(0, 1fr); gap: 8%; border-top: 1px solid var(--line); padding-block: 45px 84px; }
.article-nav { align-self: start; font-size: .88rem; }
.article-nav h2 { font-family: inherit; font-weight: 650; font-size: .9rem; letter-spacing: 0; margin-bottom: 12px; }
.article-nav ol { list-style: none; padding: 0; margin: 0; }
.article-nav li + li { margin-top: 4px; }
.article-nav a { display: flex; align-items: center; min-height: 44px; padding-block: 8px; }
.mobile-contents { display: none; }
.prose { max-width: 68ch; min-width: 0; }
.prose section + section { margin-top: 48px; }
.prose h2 { font-size: clamp(1.65rem, 3vw, 2rem); margin-bottom: 22px; }
.prose h3 { margin-bottom: 10px; }
.prose li p { margin-top: 6px; }
.prose p a, .glossary-content .note a { display: inline-block; min-height: 44px; min-width: 44px; padding-block: 7px; }
.section-words { margin-top: 22px; }
.section-words > p { color: var(--muted); font-size: .8rem; }
.section-words ul { display: flex; flex-wrap: wrap; gap: 4px 18px; list-style: none; padding: 0; margin: 3px 0 0; }
.section-words li + li { margin: 0; }
.section-words a { display: inline-flex; align-items: center; min-height: 44px; min-width: 44px; font-size: .87rem; }
.note { padding: 22px 24px; background: var(--wash); border: 1px solid var(--line); border-radius: var(--radius); margin-block: 28px; }
.note p { font-size: .95rem; }
.checklist { padding-left: 1.2em; }
.checklist li { padding-left: 7px; }
.checklist li::marker { color: var(--accent); }
.family-table { width: 100%; border-collapse: collapse; margin-block: 26px; font-size: .93rem; table-layout: fixed; }
.family-table caption { text-align: left; font-size: .83rem; color: var(--muted); padding-bottom: 13px; }
.family-table th, .family-table td { padding: 17px 15px 17px 0; text-align: left; border-bottom: 1px solid var(--line); vertical-align: top; overflow-wrap: anywhere; }
.family-table thead { background: var(--wash); }
.family-table thead th { padding-left: 12px; font-size: .82rem; }
.family-table tbody th { font-weight: 600; }
.family-table td { padding-left: 12px; }
.table-subtitle { display: block; font-size: .9rem; }
.record-figure { margin-block: 26px; }
.block-chain { list-style: none; padding: 0; margin: 0 0 16px; display: flex; gap: 18px; }
.block-chain li { position: relative; flex: 1; padding: 14px; background: var(--white); border: 1px solid var(--line); font-size: .9rem; font-weight: 650; }
.block-chain li + li { margin: 0; }
.block-chain li + li::before { content: ""; position: absolute; width: 18px; left: -19px; top: 50%; border-top: 1px solid var(--accent); }
.block-chain span { display: block; margin-top: 5px; font-weight: 400; font-size: .78rem; }
.consensus { margin-block: 28px; }
.consensus-pair { display: grid; grid-template-columns: 1fr 1fr; border: 1px solid var(--line); border-radius: var(--radius); background: var(--white); }
.consensus-pair > div { padding: 25px; }
.consensus-pair > div + div { border-left: 1px solid var(--line); }
.consensus-pair ol { list-style: none; padding: 0; margin: 22px 0; }
.consensus-pair li { padding-bottom: 17px; font-size: .95rem; }
.consensus-pair li + li { position: relative; margin-top: 16px; padding: 20px 0 0; border-top: 1px solid var(--line); }
.consensus-pair li + li::before { content: ""; position: absolute; left: 50%; top: -7px; width: 11px; height: 11px; border-bottom: 1px solid var(--accent); border-right: 1px solid var(--accent); transform: rotate(45deg); background: var(--white); }
.consensus-pair > div > p { color: var(--muted); font-size: .83rem; }
.consensus figcaption { margin-top: 14px; }
.red-flags { padding-left: 1.3em; }
.red-flags li { padding-left: 8px; }
.red-flags li + li { margin-top: 25px; }
.types { margin: 0; }
.types dt { font-weight: 650; margin-bottom: 7px; }
.types dd { margin: 0 0 24px; }
.next-lesson { margin-top: 48px; border-top: 1px solid var(--line); padding-top: 22px; }
.next-lesson p { font-size: .84rem; color: var(--muted); }
.next-lesson a { display: flex; align-items: center; gap: 9px; min-height: 44px; padding-block: 8px; font-size: 1.05rem; font-weight: 650; }
.next-lesson .previous-guide { margin-block: 6px; font-size: .87rem; font-weight: 500; }
.source-list { margin-top: 30px; }
.source-list ul { list-style: none; padding-left: 0; margin-top: 8px; }
.source-list summary { min-height: 44px; padding-block: 8px; cursor: pointer; font-weight: 600; font-size: .88rem; }
.source-list a { display: inline-flex; align-items: center; min-height: 44px; font-size: .88rem; }
.glossary-content { max-width: 870px; padding-bottom: 80px; }
.letter-nav { display: flex; gap: 5px; flex-wrap: wrap; border-block: 1px solid var(--line); padding-block: 16px; }
.letter-nav a { display: inline-grid; place-items: center; min-width: 44px; min-height: 44px; font-size: .9rem; font-weight: 650; }
.term-group { display: grid; grid-template-columns: 75px 1fr; gap: 20px; border-bottom: 1px solid var(--line); padding-block: 35px; }
.term-group h2 { font-size: 2.3rem; }
.term-group dl { margin: 0; }
.term-group dt { font-size: 1.08rem; font-weight: 650; scroll-margin-top: 25px; }
.term-group dd { margin: 7px 0 30px; max-width: 65ch; }
.term-group dd:last-child { margin-bottom: 0; }
.term-back { grid-column: 2; justify-self: start; font-size: .8rem; }
.missing-links { list-style: none; padding: 0; margin: 0 0 70px; }
.missing-links a { display: inline-flex; align-items: center; min-height: 44px; }
.site-footer { padding-block: 40px; }
.footer-inner { display: grid; grid-template-columns: 1fr auto; align-items: start; gap: 26px; }
.footer-inner p { margin-top: 14px; font-size: .84rem; color: var(--muted); max-width: 47ch; }
.footer-nav { display: flex; flex-wrap: wrap; gap: 6px 24px; font-size: .84rem; }
.footer-nav a { display: inline-flex; min-height: 44px; align-items: center; }
@keyframes settle { from { opacity: .92; } to { opacity: 1; } }
@keyframes payment-step {
  from { background: var(--white); }
  to { background: var(--wash); }
}
@keyframes payment-link { from { border-color: var(--line); } to { border-color: var(--accent); } }
@keyframes section-arrive { from { opacity: .92; } to { opacity: 1; } }
@media (prefers-reduced-motion: no-preference) {
  .payment-figure .diagram-number { animation: payment-step .6s ease-out .3s both; }
  .payment-figure li:nth-child(2) .diagram-number { animation-delay: 1.1s; }
  .payment-figure li:nth-child(3) .diagram-number { animation-delay: 1.9s; }
  .payment-figure li:not(:last-child)::after { animation: payment-link .6s ease-out .9s both; }
  .payment-figure li:nth-child(2)::after { animation-delay: 1.7s; }
  .is-entering { animation: section-arrive .6s cubic-bezier(.16, 1, .3, 1); }
}
@media (max-width: 1000px) {
  .wrap { width: calc(100% - 56px); }
  .header-inner { gap: 20px; }
  .site-nav { gap: 7px 18px; }
  .home-hero { gap: 6%; padding-block: 65px 70px; }
  .payment-figure { padding: 25px; }
  .path-layout, .learn-layout { gap: 7%; }
  .article-layout { grid-template-columns: 190px minmax(0, 1fr); gap: 6%; }
  .consensus-pair > div { padding: 18px; }
}
@media (max-width: 760px) {
  .wrap { width: calc(100% - 40px); }
  .header-inner { flex-wrap: wrap; min-height: 80px; gap: 0 12px; padding-block: 15px; }
  .brand { font-size: 1rem; }
  .brand img { width: 30px; height: 30px; }
  .site-nav { width: 100%; gap: 0; padding-top: 12px; }
  .site-nav a { width: 100%; min-height: 48px; border-top: 1px solid var(--line); }
  /* Match the deferred menu's closed state before the header is first painted. */
  .nav-ready .site-nav { display: none; }
  .nav-ready .menu-toggle[aria-expanded="true"] + .site-nav { display: flex; }
  .nav-ready .menu-toggle { display: block; }
  .home-hero { grid-template-columns: 1fr; gap: 40px; padding-block: 44px 52px; }
  h1 { max-width: 15ch; }
  .home-intro > p { margin-top: 20px; }
  .payment-figure { padding: 26px; }
  .path-layout, .learn-layout { grid-template-columns: 1fr; gap: 35px; }
  .learning-section, .learn-section { padding-block: 46px; }
  .home-reminder { padding-block: 48px; }
  .learning-path li { gap: 10px; grid-template-columns: 28px 1fr 14px; }
  .learning-path h3 { font-size: 1rem; }
  .path-layout .text-link { margin-top: 16px; }
  .page-intro { padding-block: 15px 36px; }
  .page-intro .lede { margin-top: 23px; }
  .breadcrumbs { padding-block: 16px; }
  .home-breadcrumb { padding-block: 0; }
  .article-layout { grid-template-columns: 1fr; gap: 35px; padding-block: 28px 55px; }
  .article-nav { display: none; }
  .mobile-contents { display: block; padding-bottom: 16px; border-bottom: 1px solid var(--line); font-size: .9rem; }
  .mobile-contents summary { min-height: 44px; padding-block: 8px; cursor: pointer; font-weight: 600; }
  .mobile-contents ol { list-style: none; padding: 0; margin-block: 10px 0; }
  .mobile-contents li + li { margin: 0; }
  .mobile-contents a { display: flex; align-items: center; min-height: 44px; padding-block: 5px; }
  .prose section + section { margin-top: 38px; }
  .prose h2 { margin-bottom: 18px; }
  .family-table { font-size: .85rem; }
  .family-table th, .family-table td { padding-block: 15px; padding-right: 7px; }
  .table-subtitle { font-size: .85rem; }
  .term-group { grid-template-columns: 35px minmax(0,1fr); gap: 16px; }
  .term-group h2 { font-size: 1.9rem; }
  .term-group dt { overflow-wrap: anywhere; }
  .footer-inner { grid-template-columns: 1fr; }
}
@media (max-width: 440px) {
  .consensus-pair { grid-template-columns: 1fr; }
  .consensus-pair > div { padding: 24px; }
  .consensus-pair > div + div { border-left: 0; border-top: 1px solid var(--line); }
  .block-chain { flex-direction: column; gap: 14px; }
  .block-chain li + li::before { width: 0; height: 14px; left: 50%; top: -15px; border-top: 0; border-left: 1px solid var(--accent); }
  .button { width: 100%; gap: 12px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}
@media print {
  .site-header, .site-footer, .article-nav, .letter-nav, .learn-section { display: none; }
  .wrap { width: 100%; }
  .article-layout, .home-hero, .path-layout { display: block; }
  body { background: white; color: black; }
  a { color: inherit; }
}