/* Round 4 prep book — readable, tabular, print-friendly, no JS */
:root {
  --ink: #0f172a;
  --muted: #334155;
  --faint: #64748b;
  --line: #e2e8f0;
  --bg: #f4f6f8;
  --card: #ffffff;
  --say: #0f766e;
  --say-bg: #f0fdfa;
  --ask: #1d4ed8;
  --ask-bg: #eff6ff;
  --keep: #b45309;
  --keep-bg: #fffbeb;
  --tighten: #4338ca;
  --tighten-bg: #eef2ff;
  --plain: #f8fafc;
  --radius: 10px;
  --shadow: 0 1px 2px rgba(15, 23, 42, 0.06);
  --max: 74rem;
}

* { box-sizing: border-box; }

html { font-size: 17px; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: "IBM Plex Sans", "Source Sans 3", "Segoe UI", system-ui, sans-serif;
  line-height: 1.55;
}
/* Round 4 pages use .site + .wrap. Older notebook chapters have neither. */
body:not(:has(.site)) {
  max-width: var(--max);
  margin: 0 auto;
  padding: 1.25rem 1.25rem 4rem;
}

.site {
  background: #0f172a;
  color: #e2e8f0;
  position: sticky;
  top: 0;
  z-index: 20;
  box-shadow: 0 1px 0 rgba(0,0,0,0.2);
}
.site-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.7rem 1.25rem 0.85rem;
}
.brand {
  margin: 0 0 0.45rem;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: #94a3b8;
}
.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.45rem;
  font-size: 0.86rem;
  margin: 0;
  padding: 0;
  border: 0;
  font-family: inherit;
}
.nav a {
  color: #e2e8f0;
  text-decoration: none;
  border: 1px solid #334155;
  background: #1e293b;
  padding: 0.22rem 0.55rem;
  border-radius: 999px;
  white-space: nowrap;
}
.nav a:hover, .nav a[aria-current="page"], .nav strong {
  background: #f8fafc;
  color: #0f172a;
  border-color: #f8fafc;
}
.nav strong { font-weight: 650; padding: 0.22rem 0.55rem; border-radius: 999px; }

.wrap {
  max-width: var(--max);
  margin: 0 auto;
  padding: 1.25rem 1.25rem 4rem;
}

h1, h2, h3, h4 {
  font-weight: 650;
  line-height: 1.25;
  letter-spacing: -0.02em;
}
h1 { font-size: 1.85rem; margin: 0.4rem 0 0.7rem; }
h2 { font-size: 1.28rem; margin: 0 0 0.55rem; }
h3 { font-size: 1.02rem; margin: 1.15rem 0 0.4rem; color: var(--muted); }
h4 { font-size: 0.95rem; margin: 0.9rem 0 0.3rem; }

.lede {
  font-size: 1.02rem;
  color: var(--muted);
  max-width: 52rem;
}
.pager {
  font-size: 0.88rem;
  color: var(--faint);
  margin: 0.4rem 0 1rem;
}
.pager a { color: var(--ask); }

.toc {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0.85rem 1.1rem;
  margin: 1.1rem 0 1.6rem;
  box-shadow: var(--shadow);
  font-size: 0.95rem;
}
.toc p { margin: 0 0 0.4rem; }
.toc ol, .toc ul { margin: 0.2rem 0 0; padding-left: 1.2rem; }
.toc a { color: var(--ask); }

.prep, .unit, .why-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 1.15rem 1.25rem 1.3rem;
  margin: 1.35rem 0 1.6rem;
  box-shadow: var(--shadow);
}
.prep > h2, .unit > h2, .why-card > h3 {
  margin-top: 0;
  padding-bottom: 0.45rem;
  border-bottom: 1px solid var(--line);
  color: var(--ink);
}

.plain {
  background: var(--plain);
  border-radius: 8px;
  padding: 0.7rem 0.85rem;
  margin: 0.6rem 0 0.9rem;
}

ul.might { margin: 0.3rem 0 0.5rem; padding-left: 1.2rem; }
.src { font-size: 0.88rem; color: var(--faint); }

.say, .spoken {
  border-left: 4px solid var(--say);
  background: var(--say-bg);
  padding: 0.75rem 0.95rem;
  margin: 0.55rem 0 1rem;
  border-radius: 0 8px 8px 0;
}
.then {
  background: var(--ask-bg);
  border-left: 4px solid var(--ask);
  padding: 0.75rem 0.95rem;
  margin: 0.55rem 0 1rem;
  border-radius: 0 8px 8px 0;
}
.keep, .never, .dont {
  border-left: 4px solid var(--keep);
  background: var(--keep-bg);
  padding: 0.7rem 0.95rem;
  margin: 0.55rem 0 1rem;
  border-radius: 0 8px 8px 0;
}
ul.keep {
  list-style: disc;
  padding-left: 1.3rem;
}
.tighten {
  border-left: 4px solid var(--tighten);
  background: var(--tighten-bg);
  padding: 0.7rem 0.95rem;
  margin: 0.55rem 0 0.3rem;
  border-radius: 0 8px 8px 0;
}
.say p, .then p, .keep p, .never p, .dont p, .spoken p, .tighten p, ul.keep li {
  margin: 0.4rem 0;
}

.table-wrap {
  overflow-x: auto;
  margin: 0.5rem 0 1rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--card);
}
table {
  border-collapse: collapse;
  width: 100%;
  min-width: 36rem;
  font-size: 0.92rem;
  margin: 0;
}
th, td {
  border-bottom: 1px solid var(--line);
  padding: 0.5rem 0.65rem;
  text-align: left;
  vertical-align: top;
}
th {
  background: #f1f5f9;
  font-weight: 650;
  white-space: nowrap;
}
tr:last-child td { border-bottom: 0; }
td:first-child { font-weight: 550; width: 38%; }

.tag {
  display: inline-block;
  font-size: 0.7rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  border: 1px solid #94a3b8;
  padding: 0 0.38rem;
  margin-left: 0.25rem;
  border-radius: 4px;
  vertical-align: middle;
  white-space: nowrap;
}
.tag.ie { background: #dbeafe; border-color: #93c5fd; color: #1e3a8a; }
.tag.resume { background: #dcfce7; border-color: #86efac; color: #14532d; }
.tag.std { background: #f1f5f9; border-color: #cbd5e1; color: #334155; }

pre, code { font-family: "IBM Plex Mono", Consolas, "Courier New", monospace; font-size: 0.84rem; }
pre {
  background: #0f172a;
  color: #e2e8f0;
  border-radius: 8px;
  padding: 0.9rem 1rem;
  overflow-x: auto;
  line-height: 1.45;
  white-space: pre-wrap;
}
p code, li code, td code {
  background: #f1f5f9;
  padding: 0.05rem 0.28rem;
  border-radius: 4px;
}

.note {
  border-left: 4px solid #64748b;
  padding: 0.55rem 0.8rem;
  background: #fff;
  border-radius: 0 8px 8px 0;
}
.probe {
  font-style: normal;
  background: var(--ask-bg);
  padding: 0.65rem 0.85rem;
  border-radius: 8px;
}
.answer { margin: 0.5rem 0 1rem; }
.eg { color: var(--muted); }

.facts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr));
  gap: 0.75rem;
  margin: 0.8rem 0 1.2rem;
}
.fact {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.8rem 0.9rem;
  box-shadow: var(--shadow);
}
.fact h3 { margin: 0 0 0.3rem; color: var(--ink); font-size: 1rem; }
.fact p { margin: 0.25rem 0; font-size: 0.92rem; color: var(--muted); }

footer.site-foot {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 1.25rem 2.5rem;
  font-size: 0.88rem;
  color: var(--faint);
}
footer.site-foot a { color: var(--ask); }

/* Clickable LP / behavioral question bank */
.lp-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin: 0.6rem 0 1rem;
  padding: 0;
  list-style: none;
}
.lp-jump a {
  color: var(--ask);
  text-decoration: none;
  border: 1px solid #bfdbfe;
  background: var(--ask-bg);
  padding: 0.28rem 0.6rem;
  border-radius: 999px;
  font-size: 0.84rem;
  white-space: nowrap;
}
.lp-jump a:hover { background: #dbeafe; }
.qbank {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0.7rem 1rem 0.9rem;
  margin: 0.8rem 0 1.4rem;
  box-shadow: var(--shadow);
}
.qbank h3 { margin-top: 0.85rem; }
.qbank h3:first-child { margin-top: 0.2rem; }
.qbank ol, .qbank ul { margin: 0.25rem 0 0.6rem; padding-left: 1.2rem; }
.qbank li { margin: 0.35rem 0; }
.qbank a { color: var(--ask); font-weight: 550; }
.alias, .lp-name {
  display: inline;
  font-size: 0.82rem;
  color: var(--faint);
  font-weight: 400;
}
.lp-name { color: var(--muted); }
.back { font-size: 0.88rem; margin: 0.4rem 0 0; }
.back a { color: var(--ask); }
.prep, .qbank, article[id], section[id], h2[id] {
  scroll-margin-top: 5.75rem;
}
.prep:target, .qbank:target, article:target, section:target, h2:target {
  outline: 2px solid #93c5fd;
  outline-offset: 3px;
  box-shadow: 0 0 0 6px #eff6ff, var(--shadow);
}
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.85rem;
  margin: 0.8rem 0 1.2rem;
}
.split .fact { margin: 0; }
@media (max-width: 720px) {
  .split { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
  html { font-size: 16px; }
  .wrap { padding: 1rem 0.85rem 3rem; }
  .site-inner { padding: 0.65rem 0.85rem 0.75rem; }
  h1 { font-size: 1.45rem; }
  table { min-width: 28rem; }
  .prep, .unit, .why-card { padding: 0.95rem 0.85rem 1.05rem; }
}

@media print {
  :root { --bg: #fff; }
  body { background: #fff; }
  .site, .nav, .pager { display: none; }
  .prep, .unit, .why-card, .toc, .fact { box-shadow: none; break-inside: avoid; }
  a { color: #000; text-decoration: none; }
  .say, .keep, .then, .tighten { background: #fff; }
}