/* saikia.in -- shared styles for the course site.
   Same colour tokens as the course simulations (STA102/BiSem2026/assets/style.css),
   so every page on the site looks like one system in light and dark. */

:root {
  color-scheme: light;
  --page:      #f9f9f7;
  --surface:   #fcfcfb;
  --surface-2: #f3f2ee;
  --ink-1:     #0b0b0b;
  --ink-2:     #52514e;
  --ink-3:     #898781;
  --grid:      #e1e0d9;
  --axis:      #c3c2b7;
  --border:    rgba(11,11,11,0.10);
  --s1: #2a78d6;  --s2: #eb6834;  --s3: #1baf7a;  --s4: #eda100;
  --s1-wash: rgba(42,120,214,0.10);
  --accent: #2a78d6; --accent-ink: #ffffff;
  --radius: 10px;
  --shadow: 0 1px 2px rgba(0,0,0,0.04), 0 2px 10px rgba(0,0,0,0.04);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root:where(:not([data-theme="light"])) {
    color-scheme: dark;
    --page:#0d0d0d; --surface:#1a1a19; --surface-2:#232321;
    --ink-1:#ffffff; --ink-2:#c3c2b7; --ink-3:#898781;
    --grid:#2c2c2a; --axis:#383835; --border:rgba(255,255,255,0.10);
    --s1:#3987e5; --s2:#d95926; --s3:#199e70; --s4:#c98500;
    --s1-wash: rgba(57,135,229,0.14);
    --accent:#3987e5; --accent-ink:#ffffff;
    --shadow: none;
  }
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --page:#0d0d0d; --surface:#1a1a19; --surface-2:#232321;
  --ink-1:#ffffff; --ink-2:#c3c2b7; --ink-3:#898781;
  --grid:#2c2c2a; --axis:#383835; --border:rgba(255,255,255,0.10);
  --s1:#3987e5; --s2:#d95926; --s3:#199e70; --s4:#c98500;
  --s1-wash: rgba(57,135,229,0.14);
  --accent:#3987e5; --accent-ink:#ffffff;
  --shadow: none;
}

* { box-sizing: border-box; }
html, body { margin: 0; }
body { background: var(--page); color: var(--ink-1); line-height: 1.55; font-size: 16px;
       -webkit-font-smoothing: antialiased; }
a { color: var(--accent); }
a:hover { text-decoration-thickness: 2px; }
h1, h2, h3 { line-height: 1.25; margin: 0 0 0.4em; }
h1 { font-size: clamp(1.8rem, 4vw, 2.6rem); letter-spacing: -0.015em; }
h2 { font-size: 1.3rem; }
h3 { font-size: 1.1rem; }
p { margin: 0 0 0.8em; }

/* ---------- site chrome ---------- */
.site { position: sticky; top: 0; z-index: 20; display: flex; align-items: center; gap: 12px;
        justify-content: space-between; padding: 10px 20px; background: var(--page);
        border-bottom: 1px solid var(--border); }
.site .home { font-weight: 650; color: var(--ink-1); text-decoration: none; white-space: nowrap; }
.site .home span { color: var(--ink-3); font-weight: 500; }
.site nav { display: flex; gap: 14px; align-items: center; font-size: 0.92rem; }
.site nav a { color: var(--ink-2); text-decoration: none; white-space: nowrap; }
.site nav a:hover { color: var(--ink-1); }
.theme-btn { font: inherit; font-size: 0.85rem; color: var(--ink-2); background: transparent; white-space: nowrap;
             border: 1px solid var(--border); border-radius: 999px; padding: 4px 12px; cursor: pointer; }
.theme-btn:hover { color: var(--ink-1); border-color: var(--ink-3); }
.theme-btn:focus-visible, a:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

main.page { max-width: 1060px; margin: 0 auto; padding: 26px 20px 60px; }
.crumb { font-size: 0.9rem; margin-bottom: 14px; }
.crumb a { color: var(--ink-2); text-decoration: none; }
.crumb a:hover { color: var(--ink-1); }
.eyebrow { font-size: 0.82rem; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-3); margin-bottom: 6px; }
.lede { font-size: 1.1rem; color: var(--ink-2); max-width: 62ch; }
.muted { color: var(--ink-3); }
footer.site-foot { max-width: 1060px; margin: 0 auto; padding: 20px; color: var(--ink-3);
                   font-size: 0.85rem; border-top: 1px solid var(--border); display: flex;
                   flex-wrap: wrap; gap: 6px 18px; justify-content: space-between; }
footer.site-foot a { color: var(--ink-2); }

/* ---------- hero with the Galton board ---------- */
.hero { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr); gap: 36px; align-items: center;
        padding: 18px 0 8px; }
.hero h1 { margin-bottom: 0.3em; }
.hero-art { background: var(--surface); border: 1px solid var(--border); border-radius: 14px; box-shadow: var(--shadow);
            padding: 12px 12px 10px; }
.hero-art canvas { display: block; width: 100%; }
.hero-art .art-foot { display: flex; align-items: center; justify-content: space-between; gap: 10px;
                      font-size: 0.82rem; color: var(--ink-3); margin-top: 6px; }
.hero-art .art-foot button { font: inherit; font-size: 0.82rem; color: var(--ink-2); background: transparent; white-space: nowrap;
                             border: 1px solid var(--border); border-radius: 999px; padding: 3px 11px; cursor: pointer; }
.hero-art .art-foot button:hover { color: var(--ink-1); border-color: var(--ink-3); }
@media (max-width: 820px) { .hero { grid-template-columns: minmax(0, 1fr); gap: 20px; } }

/* ---------- sections and cards ---------- */
.section { margin: 40px 0 10px; }
.section > h2 { margin-bottom: 4px; }
.section > .sub { color: var(--ink-3); font-size: 0.95rem; margin-bottom: 14px; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 14px; }

.course { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
          box-shadow: var(--shadow); padding: 18px 18px 16px; display: flex; flex-direction: column; }
.course .meta { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin-bottom: 8px; }
.code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 0.8rem; font-weight: 700;
        color: var(--accent); background: var(--s1-wash); border-radius: 6px; padding: 2px 8px; }
.term { font-size: 0.82rem; color: var(--ink-3); }
.course h3 { margin: 0 0 6px; }
.course h3 a { color: var(--ink-1); text-decoration: none; }
.course h3 a:hover { color: var(--accent); }
.course p { color: var(--ink-2); font-size: 0.95rem; }
.course .links { display: flex; flex-wrap: wrap; gap: 8px; margin-top: auto; padding-top: 6px; }

a.btn { display: inline-flex; align-items: center; gap: 6px; font-size: 0.92rem; font-weight: 550; text-decoration: none;
        border-radius: 8px; padding: 7px 14px; border: 1px solid var(--accent); background: var(--accent);
        color: var(--accent-ink); transition: filter .12s; }
a.btn:hover { filter: brightness(1.08); }
a.btn.ghost { background: transparent; color: var(--ink-1); border-color: var(--border); }
a.btn.ghost:hover { border-color: var(--ink-3); filter: none; }

.panel { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
         box-shadow: var(--shadow); padding: 20px; margin: 18px 0; }
.panel > h2:first-child { margin-top: 0; }

.facts { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 10px; margin: 18px 0 6px; }
.fact { border: 1px solid var(--border); border-radius: 9px; padding: 10px 12px; background: var(--surface); }
.fact .k { font-size: 0.8rem; color: var(--ink-2); }
.fact .v { font-size: 1.02rem; font-weight: 600; margin-top: 2px; }

.topics { list-style: none; padding: 0; margin: 8px 0 0; display: grid;
          grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 8px 18px; }
.topics li { display: flex; gap: 10px; align-items: baseline; color: var(--ink-1); }
.topics li b { flex: none; font-variant-numeric: tabular-nums; font-size: 0.8rem; color: var(--ink-3); width: 1.4em; }
.topics li span { color: var(--ink-2); font-size: 0.93rem; }

.decks { list-style: none; padding: 0; margin: 10px 0 14px; }
.decks li { display: flex; justify-content: space-between; gap: 12px; padding: 8px 2px; border-bottom: 1px solid var(--grid); }
.decks li:last-child { border-bottom: 0; }
.decks a { color: var(--ink-1); text-decoration: none; }
.decks a:hover { color: var(--accent); }
.decks .n { color: var(--ink-3); font-size: 0.88rem; white-space: nowrap; font-variant-numeric: tabular-nums; }

.note { font-size: 0.88rem; color: var(--ink-3); }

@media (max-width: 560px) {
  .site { padding: 10px 16px; }
  .site .home span { display: none; }
  main.page { padding: 20px 16px 48px; }
  .grid { grid-template-columns: minmax(0, 1fr); }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }