/* lecture-theme.css: the lectures' colours as tokens, so the pages follow
   the reader's system: night by default, day when the system is light.
   Colours are RGB triplets, used as rgba(var(--c-ink), 0.72), so every
   alpha the pages already use keeps its meaning in both themes.
   The drawn figures (the live canvases, Aristotle's square, the solids)
   are made of light on dark; in daylight they keep the night tokens and
   sit on a dark plate, like a photograph on a page. */
:root,
canvas.fig, #fig-square, #fig-solids {
  --c-ink: 240, 234, 220;     /* body text and hairlines */
  --c-text: 240, 234, 220;    /* body's base colour */
  --c-head: 242, 234, 216;    /* headings */
  --c-gold: 224, 185, 106;    /* links and accents */
  --c-gold2: 232, 192, 110;
  --c-warm: 240, 220, 160;
  --c-cool: 200, 205, 240;    /* cool lines and labels */
  --c-ground: 6, 8, 15;       /* panels and bars over the page */
  --c-btn: 224, 185, 106;     /* gold buttons with dark text */
  --c-page: linear-gradient(180deg, #06080f, #0b0e1c 55%, #0d1020);
  --c-logo: invert(1) brightness(1.7);
}
:root { color-scheme: dark; }

@media (prefers-color-scheme: light) {
  :root {
    color-scheme: light;
    --c-ink: 44, 36, 32;
    --c-text: 44, 36, 32;
    --c-head: 34, 28, 24;
    --c-gold: 138, 98, 28;
    --c-gold2: 150, 110, 40;
    --c-warm: 150, 115, 50;
    --c-cool: 70, 78, 120;
    --c-ground: 240, 234, 222;
    --c-btn: 196, 162, 78;
    --c-page: linear-gradient(180deg, #fdfbf7, #f8f4ec 55%, #f4efe5);
    --c-logo: none;
  }
  canvas.fig { background: #0b0e1c; }
  #fig-square, #fig-solids { background: #0d1020; border-color: transparent; color: rgb(var(--c-text)); }
}