:root {
  --ink: #12213a;
  --muted: #536278;
  --paper: #ffffff;
  --canvas: #f5f7fb;
  --line: #dce3ee;
  --blue: #315fce;
  --blue-dark: #21459f;
  --blue-soft: #edf3ff;
  --gold: #f4b740;
  --green: #13795b;
  --green-soft: #eaf8f3;
  --orange: #a34d12;
  --orange-soft: #fff4e9;
  --shadow: 0 18px 50px rgba(22, 39, 72, .10);
  --radius: 18px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--canvas);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 18px;
  line-height: 1.68;
  text-rendering: optimizeLegibility;
}
a { color: var(--blue-dark); text-decoration-thickness: .09em; text-underline-offset: .16em; }
a:hover { color: var(--blue); }
img { max-width: 100%; height: auto; }
.skip-link { position: absolute; left: -9999px; top: 8px; z-index: 100; background: var(--ink); color: #fff; padding: .65rem 1rem; border-radius: 8px; }
.skip-link:focus { left: 8px; }
.site-header { background: rgba(255,255,255,.96); border-bottom: 1px solid var(--line); position: relative; z-index: 5; }
.header-inner { width: min(1120px, calc(100% - 36px)); margin: 0 auto; min-height: 76px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: flex; align-items: center; gap: 12px; color: var(--ink); font-weight: 800; letter-spacing: -.02em; }
.brand-mark { display: inline-grid; place-items: center; width: 38px; height: 38px; border-radius: 11px; background: var(--ink); color: #fff; font-size: 14px; letter-spacing: .04em; }
.brand-sub { color: var(--muted); font-size: 14px; font-weight: 650; display: block; letter-spacing: .01em; }
.study-nav { display: flex; align-items: center; gap: 16px; font-size: 15px; font-weight: 750; }
.study-nav a { text-decoration: none; padding: .45rem .72rem; border-radius: 9px; }
.study-nav a:hover { background: var(--blue-soft); }
.hero { background: linear-gradient(145deg, #f9fbff 0%, #edf3ff 60%, #fff7e7 100%); border-bottom: 1px solid var(--line); }
.hero-inner { width: min(960px, calc(100% - 36px)); margin: 0 auto; padding: 78px 0 66px; }
.eyebrow { margin: 0 0 12px; color: var(--blue-dark); font-size: 14px; font-weight: 850; letter-spacing: .11em; text-transform: uppercase; }
h1, h2, h3 { line-height: 1.15; letter-spacing: -.035em; }
h1 { font-size: clamp(2.45rem, 7vw, 4.7rem); margin: 0 0 22px; max-width: 13ch; }
.hero-deck { font-size: clamp(1.13rem, 2.4vw, 1.4rem); line-height: 1.55; color: #31415b; max-width: 760px; margin: 0 0 24px; }
.meta-row { display: flex; flex-wrap: wrap; gap: 10px 18px; color: var(--muted); font-size: 14px; }
.status-pill { display: inline-flex; align-items: center; gap: 8px; padding: .3rem .7rem; border-radius: 999px; background: var(--green-soft); color: var(--green); font-weight: 800; }
.status-dot { width: 8px; height: 8px; border-radius: 50%; background: currentColor; }
.page-shell { width: min(1120px, calc(100% - 36px)); margin: 0 auto; padding: 54px 0 76px; display: grid; grid-template-columns: minmax(0, 760px) minmax(220px, 280px); gap: 70px; align-items: start; }
.article { background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius); padding: clamp(28px, 5vw, 58px); box-shadow: var(--shadow); }
.article > :first-child { margin-top: 0; }
.article h2 { font-size: clamp(1.65rem, 3vw, 2.2rem); margin: 2.25em 0 .65em; }
.article h3 { font-size: 1.25rem; margin: 1.8em 0 .5em; }
.article p { margin: 0 0 1.2em; }
.article ul, .article ol { padding-left: 1.35em; }
.article li { margin-bottom: .5em; }
.article blockquote { margin: 1.6em 0; padding: .2em 0 .2em 1.25em; border-left: 4px solid var(--gold); color: #34435c; font-size: 1.06em; }
.lede { font-size: 1.18em; line-height: 1.6; color: #2b3b55; }
.callout { margin: 1.7em 0; padding: 20px 22px; border-radius: 14px; border: 1px solid var(--line); background: #f8faff; }
.callout strong { color: var(--ink); }
.callout.warning { background: var(--orange-soft); border-color: #f2c69d; color: #67310d; }
.callout.success { background: var(--green-soft); border-color: #b9e4d5; }
.sequence { margin: 1.8em 0; display: grid; gap: 10px; }
.sequence-row { display: grid; grid-template-columns: 36px 1fr; gap: 12px; align-items: start; padding: 13px 15px; background: #f7f9fc; border: 1px solid var(--line); border-radius: 12px; }
.sequence-num { display: grid; place-items: center; width: 30px; height: 30px; border-radius: 50%; background: var(--ink); color: #fff; font-size: 14px; font-weight: 800; }
.figure-link { display: block; margin: 1.8em 0; border-radius: 16px; overflow: hidden; border: 1px solid var(--line); box-shadow: 0 12px 30px rgba(25, 48, 92, .10); background: #fff; }
.figure-link img { display: block; width: 100%; }
.figure-link:focus-visible { outline: 4px solid var(--gold); outline-offset: 4px; }
.figure { margin: 1.8em 0; }
.figure img { display: block; width: 100%; border-radius: 16px; border: 1px solid var(--line); background: #fff; }
.figure figcaption { color: var(--muted); font-size: 14px; margin-top: 9px; }
.code { background: #101a2c; color: #f4f7ff; border-radius: 14px; padding: 18px 20px; overflow-x: auto; font: 14px/1.55 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }
.table-wrap { overflow-x: auto; margin: 1.6em 0; }
table { width: 100%; border-collapse: collapse; font-size: 16px; }
th, td { padding: 12px 13px; border: 1px solid var(--line); text-align: left; vertical-align: top; }
th { background: #f2f5fa; }
.side { position: sticky; top: 24px; }
.side-card { padding: 22px; border-radius: 16px; border: 1px solid var(--line); background: rgba(255,255,255,.9); }
.side-card h2 { margin: 0 0 10px; font-size: 19px; letter-spacing: -.02em; }
.side-card p, .side-card li { font-size: 14px; line-height: 1.55; color: var(--muted); }
.side-card ul { padding-left: 1.2em; margin-bottom: 0; }
.kicker { display: inline-block; font-size: 13px; font-weight: 850; color: var(--blue-dark); background: var(--blue-soft); border-radius: 999px; padding: .25rem .65rem; }
.source-note { margin-top: 2.4em; padding-top: 1.4em; border-top: 1px solid var(--line); font-size: 14px; color: var(--muted); }
.site-footer { border-top: 1px solid var(--line); background: #fff; }
.footer-inner { width: min(1120px, calc(100% - 36px)); margin: 0 auto; padding: 30px 0 42px; display: flex; justify-content: space-between; gap: 20px; color: var(--muted); font-size: 14px; }
.footer-inner a { color: inherit; }
@media (max-width: 860px) {
  .page-shell { grid-template-columns: 1fr; gap: 28px; }
  .side { position: static; }
}
@media (max-width: 620px) {
  body { font-size: 17px; }
  .header-inner { min-height: 68px; }
  .brand-sub { display: none; }
  .study-nav { font-size: 14px; }
  .hero-inner { padding: 54px 0 46px; }
  .article { border-radius: 14px; padding: 26px 22px; }
  .footer-inner { flex-direction: column; }
}
@media print {
  body { background: #fff; }
  .site-header, .side, .site-footer { display: none; }
  .hero { background: #fff; }
  .hero-inner { padding: 20px 0; }
  .page-shell { display: block; padding: 0; }
  .article { box-shadow: none; border: 0; padding: 0; }
}
/* Prevent wide code/table content from expanding grid tracks on small screens. */
.article, .side { min-width: 0; }
.article pre, .table-wrap { max-width: 100%; }
.article a { overflow-wrap: anywhere; }

/* Intentional experiment: DOM order and visible order conflict inside this block. */
.visual-order-test { display: flex; flex-direction: column; gap: 14px; margin: 1.8em 0; }
.order-card { padding: 18px 20px; border: 1px solid var(--line); border-radius: 14px; background: #f8faff; }
.order-card p { margin: .5rem 0 0; }
.order-label { display: inline-block; font-size: 13px; font-weight: 850; letter-spacing: .035em; text-transform: uppercase; color: var(--muted); }
.visual-order-test .visual-first { order: -1; background: var(--orange-soft); border-color: #f2c69d; }
.visual-order-test .dom-first { background: var(--blue-soft); border-color: #c9d8fb; }