:root {
  --navy: #152238;
  --gold: #d9a62e;
  --paper: #fbfaf6;
  --ink: #253044;
  --line: #d9dde5;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: #eef0f4;
  color: var(--ink);
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.65;
}

#navbar {
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  width: 275px;
  overflow-y: auto;
  background: var(--navy);
  color: white;
  padding: 32px 24px;
}
#navbar header {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 1.45rem;
  font-weight: 700;
}
.chess-mark {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: 50%;
  background: var(--gold);
  color: var(--navy);
  font-size: 1.5rem;
}
.nav-intro { margin: 12px 0 24px; color: #c5cfdd; font-size: 0.9rem; }
.nav-links { border-top: 1px solid #3b4b65; }
.nav-link {
  display: block;
  padding: 13px 6px;
  border-bottom: 1px solid #3b4b65;
  color: #f3f5f8;
  text-decoration: none;
}
.nav-link:hover, .nav-link:focus { color: #ffd875; }

#main-doc {
  width: min(900px, calc(100% - 335px));
  margin-left: 305px;
  padding: 48px 0 72px;
}
.page-heading, .main-section {
  padding: 34px 40px;
  border: 1px solid var(--line);
  background: var(--paper);
}
.page-heading { border-top: 6px solid var(--gold); }
.eyebrow {
  margin: 0 0 8px;
  color: #956b08;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}
h1 {
  margin: 0;
  color: var(--navy);
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(2.5rem, 7vw, 4.5rem);
  line-height: 1.08;
}
.lead { max-width: 650px; margin: 18px 0 0; font-size: 1.1rem; }
.main-section { margin-top: 22px; }
.main-section > header {
  margin-bottom: 16px;
  color: var(--navy);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 1.75rem;
  font-weight: 700;
}
.main-section p { margin: 0 0 14px; }
.main-section li { margin: 8px 0; }
.note-box {
  margin-top: 20px;
  padding: 16px 18px;
  border-left: 4px solid var(--gold);
  background: #fff4cf;
}
code {
  padding: 2px 6px;
  border: 1px solid #cfd5df;
  border-radius: 4px;
  background: #f1f3f7;
  color: #7b3f00;
  font-family: "Courier New", monospace;
  font-size: 0.92em;
}
.rule-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 20px 0;
}
.rule-grid article, .faq-list article {
  padding: 16px;
  border: 1px solid var(--line);
  background: white;
}
.rule-grid h2, .faq-list h2, .example-box h2 {
  margin: 0 0 8px;
  color: var(--navy);
  font-size: 1.05rem;
}
.rule-grid p, .faq-list p { margin: 0; }
.example-box {
  margin-top: 20px;
  padding: 20px;
  border: 1px solid #aebbd0;
  background: #edf3fc;
}
.tip-list { padding-left: 22px; }
.faq-list { display: grid; gap: 12px; }
.closing-note {
  margin-top: 22px !important;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-style: italic;
}

@media (max-width: 820px) {
  #navbar { position: static; width: 100%; max-height: none; }
  .nav-links { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); }
  #main-doc { width: min(100% - 28px, 900px); margin: 0 auto; padding: 24px 0 48px; }
  .page-heading, .main-section { padding: 26px 22px; }
  .rule-grid { grid-template-columns: 1fr; }
}

@media (max-width: 520px) {
  .nav-links { grid-template-columns: 1fr; }
}