:root {
  --ink: #111c2d;
  --ink-2: #26364e;
  --paper: #f4f6f8;
  --card: #ffffff;
  --line: #d6dde6;
  --muted: #5a6a80;
  --accent: #c8400b;
  --accent-dark: #9c3008;
  --signal: #14808f;
  --tint: #e8f1f3;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, "Times New Roman", serif;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --radius: 10px;
  --wrap: 1120px;
  --measure: 46rem;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--sans);
  font-size: 1.0625rem;
  line-height: 1.68;
  color: var(--ink);
  background: var(--paper);
  overflow-wrap: break-word;
}
img, svg { max-width: 100%; height: auto; }
a { color: var(--signal); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--accent-dark); }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; border-radius: 3px; }

.skip { position: absolute; left: -999px; top: 0; background: var(--accent); color: #fff; padding: .6rem 1rem; z-index: 10; }
.skip:focus { left: 0; }

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 1.25rem; }

/* header */
.site-header { background: var(--ink); color: #e9eef5; border-bottom: 4px solid var(--accent); }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding-top: .9rem; padding-bottom: .9rem; position: relative; }
.brand { display: inline-flex; align-items: center; gap: .65rem; color: #fff; text-decoration: none; font-family: var(--serif); font-weight: 700; font-size: 1.45rem; letter-spacing: .01em; }
.brand:hover { color: #fff; }
.brand svg { flex: none; }
.brand small { display: block; font: 400 .72rem/1.2 var(--sans); letter-spacing: .06em; text-transform: uppercase; color: #9fb2c8; margin-top: .1rem; }
.site-header .wrap { flex-wrap: wrap; }
.site-nav { display: flex; flex-wrap: wrap; gap: .1rem .15rem; width: 100%; }
.site-nav a { display: block; padding: .4rem .65rem; color: #dbe5f1; text-decoration: none; border-radius: 6px; font-size: .93rem; }
.site-nav a:hover, .site-nav a[aria-current="page"] { background: #36506f; color: #fff; }

/* hero */
.hero { background: linear-gradient(180deg, var(--ink) 0%, #182843 100%); color: #eef3f9; position: relative; overflow: hidden; }
.hero::before { content: ""; position: absolute; inset: 0; background-image: linear-gradient(rgba(255,255,255,.045) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.045) 1px, transparent 1px); background-size: 36px 36px; mask-image: linear-gradient(90deg, transparent, #000 55%); -webkit-mask-image: linear-gradient(90deg, transparent, #000 55%); }
.hero .wrap { position: relative; display: grid; gap: 2rem; padding-top: 3rem; padding-bottom: 3.2rem; }
.hero h1 { font-family: var(--serif); font-size: clamp(2rem, 6vw, 3.4rem); line-height: 1.1; margin: 0 0 1rem; max-width: 18ch; }
.hero p { font-size: 1.15rem; max-width: 38rem; color: #cbd7e6; margin: 0 0 1.5rem; }
.hero .eyebrow { font: 600 .8rem/1 var(--sans); letter-spacing: .14em; text-transform: uppercase; color: #ff9f6e; margin-bottom: 1rem; display: block; }
.hero-art { max-width: 420px; justify-self: center; width: 100%; }
.btn { display: inline-block; padding: .75rem 1.25rem; border-radius: 8px; background: var(--accent); color: #fff; text-decoration: none; font-weight: 600; }
.btn:hover { background: var(--accent-dark); color: #fff; }
.btn.ghost { background: transparent; border: 1px solid #5d7592; margin-left: .5rem; }
.btn.ghost:hover { background: #26405f; }

/* sections */
.section { padding: 2.6rem 0; }
.section.alt { background: #fff; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section h2 { font-family: var(--serif); font-size: 1.75rem; line-height: 1.2; margin: 0 0 1.3rem; }
.section-head { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: baseline; gap: .5rem 1rem; margin-bottom: 1.3rem; }
.section-head h2 { margin: 0; }

.grid { display: grid; gap: 1.1rem; }
.cards { grid-template-columns: 1fr; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.25rem 1.3rem 1.3rem; display: flex; flex-direction: column; }
.card h3 { font-family: var(--serif); font-size: 1.28rem; line-height: 1.25; margin: 0 0 .5rem; }
.card h3 a { color: var(--ink); text-decoration: none; }
.card h3 a:hover { color: var(--accent-dark); text-decoration: underline; }
.card p { margin: 0 0 .8rem; color: #33445c; font-size: .98rem; line-height: 1.55; }
.card .meta { margin-top: auto; }
.card.feature { border-top: 4px solid var(--accent); }
.card.topic { border-left: 4px solid var(--signal); }
.meta, .kicker { font-size: .82rem; color: var(--muted); letter-spacing: .02em; }
.kicker { text-transform: uppercase; letter-spacing: .1em; font-weight: 600; color: var(--signal); margin-bottom: .45rem; display: block; }
.tag { display: inline-block; font-size: .78rem; padding: .12rem .55rem; border-radius: 99px; background: var(--tint); color: #0e5e6a; font-weight: 600; margin-right: .35rem; }

.chrono { list-style: none; margin: 0; padding: 0; border-left: 2px solid var(--line); }
.chrono li { position: relative; padding: .1rem 0 1.15rem 1.4rem; }
.chrono li::before { content: ""; position: absolute; left: -7px; top: .55rem; width: 12px; height: 12px; border-radius: 50%; background: var(--accent); border: 2px solid var(--paper); }
.chrono time { display: block; font: 600 .82rem/1.4 var(--mono); color: var(--muted); }
.chrono a { font-weight: 600; color: var(--ink); text-decoration: none; }
.chrono a:hover { color: var(--accent-dark); text-decoration: underline; }
.chrono p { margin: .15rem 0 0; font-size: .95rem; color: #3b4c63; line-height: 1.5; }

/* article */
.crumbs { font-size: .86rem; color: var(--muted); padding: 1.1rem 0 0; }
.crumbs ol { list-style: none; display: flex; flex-wrap: wrap; gap: .3rem .5rem; margin: 0; padding: 0; }
.crumbs li + li::before { content: "/"; margin-right: .5rem; color: #9aa8bb; }
.crumbs a { color: var(--muted); }
.page-head { padding: 1.4rem 0 1.2rem; }
.page-head h1 { font-family: var(--serif); font-size: clamp(1.85rem, 5vw, 2.8rem); line-height: 1.14; margin: .2rem 0 .8rem; max-width: 26ch; }
.page-head.wide h1 { max-width: none; }
.lede { font-size: 1.2rem; line-height: 1.55; color: #2a3b54; max-width: var(--measure); margin: 0; }
.byline { margin-top: 1rem; font-size: .9rem; color: var(--muted); display: flex; flex-wrap: wrap; gap: .3rem 1.1rem; }

.layout { display: grid; gap: 2rem; padding-bottom: 3rem; }
.prose { max-width: var(--measure); min-width: 0; }
.prose > * + * { margin-top: 1.1rem; }
.prose h2 { font-family: var(--serif); font-size: 1.65rem; line-height: 1.22; margin-top: 2.4rem; padding-top: .3rem; scroll-margin-top: 1rem; }
.prose h3 { font-family: var(--serif); font-size: 1.28rem; line-height: 1.3; margin-top: 1.8rem; }
.prose p { margin-bottom: 0; }
.prose ul, .prose ol { padding-left: 1.4rem; }
.prose li + li { margin-top: .4rem; }
.prose blockquote { margin-left: 0; padding: .3rem 0 .3rem 1.2rem; border-left: 4px solid var(--accent); color: #2c3d56; font-family: var(--serif); font-size: 1.12rem; }
.prose table { width: 100%; border-collapse: collapse; font-size: .96rem; display: block; overflow-x: auto; }
.prose th, .prose td { text-align: left; border-bottom: 1px solid var(--line); padding: .55rem .7rem; vertical-align: top; }
.prose th { background: var(--tint); font-size: .85rem; letter-spacing: .03em; }
.callout { background: var(--tint); border: 1px solid #bcd7dc; border-left: 5px solid var(--signal); border-radius: 8px; padding: 1rem 1.2rem; }
.callout strong:first-child { display: block; margin-bottom: .25rem; }
.fact-list { list-style: none; padding: 0 !important; display: grid; gap: .7rem; }
.fact-list li { background: #fff; border: 1px solid var(--line); border-radius: 8px; padding: .75rem 1rem; margin: 0 !important; }
figure { margin: 1.6rem 0; }
figure svg { width: 100%; height: auto; background: #fff; border: 1px solid var(--line); border-radius: var(--radius); display: block; }
figcaption { font-size: .88rem; color: var(--muted); margin-top: .55rem; line-height: 1.45; }
code, .formula { font-family: var(--mono); background: #e7edf3; padding: .1rem .35rem; border-radius: 4px; font-size: .92em; }
.formula { display: block; text-align: center; padding: .8rem; font-size: 1.1rem; background: #fff; border: 1px solid var(--line); }

.aside { align-self: start; min-width: 0; }
.panel { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 1rem 1.15rem; font-size: .95rem; line-height: 1.5; }
.panel + .panel { margin-top: 1rem; }
.panel h2 { font: 700 .78rem/1.2 var(--sans); letter-spacing: .12em; text-transform: uppercase; color: var(--muted); margin: 0 0 .7rem; }
.panel ul { list-style: none; margin: 0; padding: 0; }
.panel li + li { margin-top: .5rem; }
.panel a { text-decoration: none; }
.panel a:hover { text-decoration: underline; }
.toc a { color: var(--ink-2); }
.sources ol { padding-left: 1.2rem; margin: 0; }
.sources li { margin: 0 0 .5rem; }

.list-plain { list-style: none; margin: 0; padding: 0; display: grid; gap: 1rem; }
.entry { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.1rem 1.25rem; }
.entry h3 { margin: .1rem 0 .35rem; font-family: var(--serif); font-size: 1.25rem; line-height: 1.28; }
.entry h3 a { color: var(--ink); text-decoration: none; }
.entry h3 a:hover { color: var(--accent-dark); text-decoration: underline; }
.entry p { margin: 0; font-size: .98rem; color: #33445c; line-height: 1.55; }

/* error pages */
.error-page { padding: 4rem 0 5rem; max-width: 40rem; }
.error-page .code { font: 700 4.5rem/1 var(--mono); color: var(--accent); }
.error-page h1 { font-family: var(--serif); font-size: 2rem; margin: .4rem 0 1rem; }

/* footer */
.site-footer { background: var(--ink); color: #b7c4d6; padding: 2.4rem 0 2rem; margin-top: 2rem; font-size: .93rem; line-height: 1.6; }
.site-footer .wrap { display: grid; gap: 1.6rem; }
.site-footer a { color: #e3ebf5; }
.site-footer h2 { font: 700 .78rem/1.2 var(--sans); letter-spacing: .12em; text-transform: uppercase; color: #8fa3bb; margin: 0 0 .7rem; }
.site-footer ul { list-style: none; margin: 0; padding: 0; }
.site-footer li + li { margin-top: .35rem; }
.legal { border-top: 1px solid #2f4260; padding-top: 1.1rem; color: #8fa3bb; font-size: .85rem; }

@media (min-width: 720px) {
  .cards.two, .cards.three { grid-template-columns: repeat(2, 1fr); }
  .site-footer .wrap { grid-template-columns: 1.4fr 1fr 1fr; }
  .hero .wrap { grid-template-columns: 1.25fr 1fr; align-items: center; }
  .site-nav { width: auto; justify-content: flex-end; }
}
@media (min-width: 1040px) {
  .cards.three { grid-template-columns: repeat(3, 1fr); }
  .layout.with-aside { grid-template-columns: minmax(0, 1fr) 300px; gap: 3rem; }
  .aside.sticky { position: sticky; top: 1rem; }
}
@media (max-width: 480px) {
  body { font-size: 1rem; }
  .btn.ghost { margin: .6rem 0 0; }
  .prose h2 { font-size: 1.45rem; }
}
@media print {
  .site-header, .site-footer, .aside { display: none; }
  body { background: #fff; }
}

/* glossary */
.glossary dt { font-weight: 700; margin-top: 1.1rem; font-family: var(--serif); font-size: 1.15rem; }
.glossary dd { margin: .2rem 0 0; }
.glossary { margin: 0; }