/* Shared course stylesheet: Tufte-inspired, print-friendly.
   Every lesson and reference doc links this file. */
@import url("https://fonts.googleapis.com/css2?family=Source+Serif+4:ital,opsz,wght@0,8..60,400;0,8..60,600;1,8..60,400&family=Inter:wght@500;600&display=swap");

:root {
  --ink: #1d1b18;
  --muted: #6b655c;
  --paper: #fffdf8;
  --rule: #e4ddd0;
  --accent: #9c2b1e;      /* card-shop red */
  --accent-soft: #f6e7e3;
  --good: #2f6b3a;
  --good-soft: #e5f1e6;
  --bad: #9c2b1e;
  --bad-soft: #f8e4e1;
  --serif: "Source Serif 4", Georgia, "Times New Roman", serif;
  --sans: "Inter", -apple-system, "Helvetica Neue", sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #ece6dc; --muted: #a69e92; --paper: #1a1916; --rule: #3a3731;
    --accent: #e0745f; --accent-soft: #3a241f;
    --good: #7fc28a; --good-soft: #1f3123; --bad: #e0745f; --bad-soft: #3a221e;
  }
}

* { box-sizing: border-box; }
html { font-size: 18px; }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font-family: var(--serif); line-height: 1.6;
}
main { max-width: 42rem; margin: 0 auto; padding: 3rem 1rem 5rem; }

/* Typography */
h1 { font-weight: 400; font-size: 2.2rem; line-height: 1.15; margin: 0 0 .3rem; }
h2 { font-weight: 400; font-style: italic; font-size: 1.45rem; margin: 2.6rem 0 .6rem; }
h3 { font-weight: 600; font-size: 1.05rem; margin: 1.6rem 0 .3rem; }
p, li { font-size: 1rem; }
a { color: var(--accent); text-underline-offset: 2px; }
.kicker {
  font-family: var(--sans); font-size: .72rem; letter-spacing: .12em;
  text-transform: uppercase; color: var(--accent); margin-bottom: .6rem;
}
.subtitle { font-style: italic; color: var(--muted); font-size: 1.15rem; margin: 0 0 2rem; }
.cite { font-size: .78rem; vertical-align: super; line-height: 0; }
.cite a { text-decoration: none; }
hr { border: 0; border-top: 1px solid var(--rule); margin: 2.5rem 0; }

/* Callouts */
.callout {
  border-left: 3px solid var(--accent); background: var(--accent-soft);
  padding: .9rem 1.1rem; margin: 1.4rem 0; border-radius: 0 4px 4px 0;
}
.callout p:first-child { margin-top: 0; } .callout p:last-child { margin-bottom: 0; }
.callout .label {
  font-family: var(--sans); font-size: .7rem; letter-spacing: .1em;
  text-transform: uppercase; color: var(--accent); display: block; margin-bottom: .25rem;
}

/* Tables */
table { border-collapse: collapse; width: 100%; margin: 1.2rem 0; font-size: .92rem; }
th, td { text-align: left; padding: .45rem .6rem; border-bottom: 1px solid var(--rule); vertical-align: top; }
th { font-family: var(--sans); font-size: .72rem; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); font-weight: 600; }

/* Lever grid (value levers) */
.levers { display: grid; grid-template-columns: 1fr 1fr; gap: .8rem; margin: 1.4rem 0; }
.lever { border: 1px solid var(--rule); border-radius: 6px; padding: .8rem 1rem; }
.lever b { font-family: var(--sans); font-size: .85rem; letter-spacing: .04em; color: var(--accent); }
.lever p { margin: .3rem 0 0; font-size: .92rem; }
@media (max-width: 560px) {
  .levers { grid-template-columns: 1fr; }
  /* Wide tables scroll inside themselves instead of widening the page */
  table { display: block; overflow-x: auto; }
  code { overflow-wrap: anywhere; }
}

/* Nav + footer */
.nav { font-family: var(--sans); font-size: .78rem; display: flex; justify-content: space-between; gap: 1rem; margin-bottom: 2.5rem; color: var(--muted); }
.nav a { text-decoration: none; }
.source-box { border: 1px solid var(--rule); border-radius: 6px; padding: 1rem 1.2rem; margin: 2rem 0; }
.ask-teacher { font-style: italic; color: var(--muted); }

/* Reference docs: denser layout */
body.reference main { max-width: 48rem; }
body.reference h2 { margin-top: 1.8rem; }

@media print {
  html { font-size: 11pt; }
  body { background: #fff; color: #000; }
  main { padding: 0; max-width: none; }
  .nav, .quiz button.reveal, .no-print { display: none; }
  a { color: #000; }
  .lever, .callout, table { break-inside: avoid; }
}