/* Prototype B · Briefing: strong headings, boxes, numbered sections, print-first. */
@import url("https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:ital,wght@0,400;0,500;0,700;1,400&family=IBM+Plex+Serif:ital@1&display=swap");

:root {
  --bg: #ffffff;
  --ink: #14202b;
  --muted: #55626f;
  --navy: #12304a;
  --amber: #f2a900;
  --amber-tint: #fff6dc;
  --panel: #eef2f6;
  --rule: #d5dde5;
  --sans: "IBM Plex Sans", system-ui, sans-serif;
  --serif: "IBM Plex Serif", Georgia, serif;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 400 1.0625rem/1.6 var(--sans); }
a { color: var(--navy); text-underline-offset: 2px; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }

.proto-banner { font-size: .8rem; font-weight: 500; background: var(--amber); color: #1b1300; padding: .45rem 1rem; text-align: center; }
.proto-banner a { color: #1b1300; }

.site-header { background: var(--navy); color: #fff; padding: 1rem max(1rem, calc((100% - 70rem) / 2)); display: flex; flex-wrap: wrap; gap: .5rem 2rem; align-items: center; justify-content: space-between; }
.site-name { color: #fff; font-weight: 700; font-size: 1.15rem; text-decoration: none; letter-spacing: .02em; }
.site-name span { color: var(--amber); }
.site-nav { display: flex; flex-wrap: wrap; gap: .25rem 1.25rem; font-size: .92rem; font-weight: 500; }
.site-nav a { color: #fff; text-decoration: none; }
.site-nav a[aria-current] { box-shadow: inset 0 -2px var(--amber); }
.nav-off { color: #9fb2c4; }
.page-article .nav-off, .related .nav-off { color: var(--muted); }
.site-nav .nav-off { color: #9fb2c4; }

main { max-width: 70rem; margin: 0 auto; padding: 0 1rem 3rem; }

/* Home */
.hero { padding: 2.5rem 0 1rem; display: grid; gap: 0 2.5rem; }
.kicker { font-size: .8rem; font-weight: 700; letter-spacing: .14em; text-transform: uppercase; color: var(--muted); margin: 0 0 .75rem; }
.hero h1 { font-size: clamp(1.9rem, 4.6vw, 3rem); line-height: 1.12; font-weight: 700; color: var(--navy); margin: 0 0 1rem; }
.lede { font-size: 1.2rem; margin: 0 0 1.5rem; max-width: 36rem; }
.hero-figure, .diagram { margin: 1rem 0 1.5rem; background: var(--panel); padding: 1rem; border-radius: 4px; }
figcaption { font-size: .82rem; color: var(--muted); margin-top: .5rem; }
svg { width: 100%; height: auto; display: block; }
svg .ground { fill: #c9d4de; }
svg .zone { fill: var(--amber); opacity: .45; }
svg .track { fill: none; stroke: var(--navy); stroke-width: 2.5; }
svg .touch { fill: var(--navy); }
svg .label { font: 500 13px var(--sans); fill: var(--navy); }

.question, .framework, .calculator { max-width: 44rem; }
section h2 { font-size: 1.4rem; color: var(--navy); margin: 2.25rem 0 .75rem; }
.calculator { background: var(--amber-tint); border-left: 6px solid var(--amber); padding: .25rem 1.5rem 1rem; margin: 2rem 0; }
.calc-sentence { font-size: 1.25rem; line-height: 2; font-weight: 500; }
.calc-sentence input { font: inherit; width: 4.6ch; border: 2px solid var(--navy); border-radius: 3px; text-align: center; background: #fff; color: var(--navy); -moz-appearance: textfield; }
.calc-sentence input::-webkit-inner-spin-button { -webkit-appearance: none; }
#calc-n { width: 3.8ch; }
.calc-sentence output { font-weight: 700; background: var(--navy); color: #fff; padding: .05rem .4rem; border-radius: 3px; }
.calc-note { font-size: .92rem; color: var(--muted); }

.fw-list { list-style: none; padding: 0; counter-reset: fw; display: grid; gap: .75rem; }
.fw-list li { counter-increment: fw; border: 1px solid var(--rule); border-radius: 4px; padding: .9rem 1rem .9rem 3.4rem; position: relative; }
.fw-list li::before { content: counter(fw); position: absolute; left: 1rem; top: .85rem; width: 1.6rem; height: 1.6rem; border-radius: 50%; background: var(--navy); color: #fff; font-weight: 700; font-size: .9rem; display: grid; place-items: center; }
.fw-list strong { display: block; color: var(--navy); }
.fw-list a { text-decoration: none; }
.fw-list a strong::after { content: " →"; color: var(--amber); }
.fw-more { color: var(--muted); font-size: .92rem; }
.cta { display: flex; flex-wrap: wrap; gap: .75rem; margin: 2rem 0; }
.cta a { display: inline-block; padding: .7rem 1.1rem; border-radius: 4px; font-weight: 500; text-decoration: none; }
.cta-primary { background: var(--navy); color: #fff; }
.cta-secondary { border: 2px solid var(--navy); }

/* Articles */
.article { display: grid; grid-template-columns: minmax(0, 1fr); gap: 0 3rem; }
.position { display: flex; flex-wrap: wrap; gap: .5rem 1.5rem; font-size: .85rem; color: var(--muted); padding-top: 1.5rem; }
.pos-here { background: var(--navy); color: #fff; font-weight: 700; padding: .1rem .55rem; border-radius: 3px; letter-spacing: .04em; }
.article h1 { font-size: clamp(1.8rem, 4.2vw, 2.5rem); line-height: 1.15; color: var(--navy); margin: 1rem 0 1.25rem; }
.subtitle { display: block; font-weight: 400; font-size: .7em; color: var(--ink); }
.key-idea { background: var(--amber-tint); border-left: 6px solid var(--amber); padding: 1rem 1.25rem; margin: 0 0 1rem; font-size: 1.12rem; font-weight: 500; }
.key-label { font-size: .75rem; font-weight: 700; letter-spacing: .14em; text-transform: uppercase; margin: 0 0 .35rem; color: #6b4b00; }
.key-idea p:last-child { margin: 0; }
.byline { font-size: .88rem; color: var(--muted); }
.author { font-weight: 700; color: var(--ink); }
.toc { background: var(--panel); border-radius: 4px; padding: .9rem 1.1rem; font-size: .92rem; margin: 1rem 0 1.5rem; }
.toc-title { font-weight: 700; text-transform: uppercase; letter-spacing: .1em; font-size: .75rem; margin: 0 0 .4rem; color: var(--navy); }
.toc ol { margin: 0; padding-left: 1.2rem; }

.body { counter-reset: sec; max-width: 44rem; }
.body h2 { counter-increment: sec; font-size: 1.3rem; color: var(--navy); margin: 2.25rem 0 .6rem; padding-top: .9rem; border-top: 2px solid var(--navy); }
.body h2::before { content: counter(sec) ". "; color: var(--amber); }
.anchor { color: var(--rule); text-decoration: none; font-weight: 400; margin-left: .3rem; }
h2:hover .anchor { color: var(--navy); }
blockquote.statement { margin: 1.25rem 0; padding: 1rem 1.25rem; background: var(--navy); color: #fff; font-size: 1.35rem; font-weight: 700; border-radius: 4px; }
blockquote.pull { margin: 1.25rem 0; padding: .25rem 0 .25rem 1rem; border-left: 4px solid var(--amber); font-family: var(--serif); font-style: italic; font-size: 1.1rem; }
.narrative { font-family: var(--serif); font-style: italic; font-size: 1.1rem; max-width: 44rem; }
.note { display: block; font-size: .84rem; color: var(--muted); background: var(--panel); border-radius: 3px; padding: .5rem .75rem; margin: -.25rem 0 1rem; }
.note-num { font-weight: 700; color: var(--navy); margin-right: .35rem; }

.glance { border: 2px solid var(--navy); border-radius: 4px; margin: 1rem 0 1.5rem; max-width: 44rem; }
.glance h2 { margin: 0; background: var(--navy); color: #fff; font-size: .8rem; letter-spacing: .14em; text-transform: uppercase; padding: .45rem 1rem; }
.glance dl { display: grid; grid-template-columns: 10rem 1fr; margin: 0; }
.glance dt, .glance dd { padding: .5rem 1rem; border-top: 1px solid var(--rule); margin: 0; font-size: .95rem; }
.glance dt { font-weight: 700; background: var(--panel); }
.factor-list dt { font-weight: 700; margin-top: .8rem; color: var(--navy); }
.factor-list dd { margin: .2rem 0 0; }
.draft-flag { font-size: .8rem; font-weight: 700; color: #6b4b00; background: var(--amber-tint); border: 1px dashed var(--amber); display: inline-block; padding: .2rem .5rem; }
.questions { counter-reset: q; list-style: none; padding: 0; }
.questions li { counter-increment: q; padding: .6rem .75rem .6rem 2.6rem; position: relative; border-bottom: 1px solid var(--rule); }
.questions li::before { content: "Q" counter(q); position: absolute; left: .5rem; font-weight: 700; color: var(--amber); }

.related, .cite { max-width: 44rem; margin-top: 2rem; border-top: 1px solid var(--rule); }
.related h2, .cite h2 { font-size: 1.05rem; }
.cite-apa { font-size: .92rem; background: var(--panel); padding: .75rem 1rem; border-radius: 4px; }
.cite summary { cursor: pointer; font-weight: 500; }
.cite pre { font-size: .8rem; background: var(--panel); padding: .75rem; overflow-x: auto; }
.license-line { font-size: .88rem; color: var(--muted); }
.site-footer { background: var(--panel); padding: 1.5rem max(1rem, calc((100% - 70rem) / 2)); font-size: .85rem; color: var(--muted); }

@media (min-width: 60rem) {
  .hero { grid-template-columns: 1.1fr 1fr; align-items: center; }
  .hero-figure { grid-column: 2; grid-row: 1 / span 3; }
  .article { grid-template-columns: 15rem minmax(0, 44rem); }
  .article > * { grid-column: 2; }
  .article > .toc { grid-column: 1; grid-row: 1 / span 20; align-self: start; position: sticky; top: 1rem; margin-top: 4.5rem; }
}

@media print {
  .proto-banner, .site-nav, .position, .toc, .anchor, .cta { display: none; }
  .site-header { background: none; color: var(--ink); padding: 0 0 .5rem; border-bottom: 2px solid var(--ink); }
  .site-name { color: var(--ink); }
  body { font-size: 10.5pt; }
  .article { display: block; }
  a[href^="http"]::after { content: " (" attr(href) ")"; font-size: .8em; }
  .body h2, .glance, .key-idea, blockquote { break-inside: avoid; }
  blockquote.statement { background: none; color: var(--ink); border: 2px solid var(--ink); }
}