:root {
  --ink:        #0b0d10;
  --paper:      #f4f2ed;
  /* --sky is the flag light blue, darkened for the default (light) scheme so
     text/UI set in it (the numeral, focus rings) clears 3:1 against --paper.
     The dark-mode override below restores the vibrant #75aadb, which already
     clears 3:1 (in fact ~7.9:1) against the dark --paper. See task-3-report.md
     for computed contrast ratios. */
  --sky:        #2a628f;   /* Argentina flag blue, darkened for light-mode contrast */
  --sky-deep:   #4a7fb0;
  /* --sky-invert is for use ONLY where --ink is pressed into service as a
     BACKGROUND (e.g. .entry--denied, which inverts ink/paper). --sky is
     tuned against --paper per scheme; --ink is a different value per scheme,
     so re-using --sky there is wrong (measured: light 3.00:1 vs required
     4.5:1 for text, dark 2.12:1 — both fail). --sky-invert is simply the
     OTHER scheme's --sky value, which is already tuned for a background
     that matches this scheme's --ink. Computed against --ink: light 7.90:1,
     dark 5.59:1 — clears 4.5:1 in both. See task-4-report.md (C2 fix). */
  --sky-invert: #75aadb;
  --gold:       #c9a227;   /* used ONLY on the 1978 and 1986 entries */
  --rule:       #d8d4cb;
  --muted:      #5a5e65;   /* darkened slightly from #6b6f76 for AA safety margin in light mode */

  --step--1: clamp(0.9rem, 0.85rem + 0.2vw, 1rem);
  --step-0:  clamp(1.05rem, 1rem + 0.3vw, 1.2rem);
  --step-1:  clamp(1.4rem, 1.2rem + 0.9vw, 2rem);
  --step-2:  clamp(2rem, 1.5rem + 2.4vw, 3.5rem);
  --step-3:  clamp(3.5rem, 2rem + 7vw, 9rem);
  --numeral: clamp(8rem, 4rem + 22vw, 22rem);

  --measure: 34rem;
  --gutter: clamp(1.25rem, 5vw, 4rem);
}
@media (prefers-color-scheme: dark) {
  :root {
    --ink: #f0eee9; --paper: #0b0d10; --rule: #262a30; --muted: #9aa0a8;
    --sky: #75aadb; /* restore the vibrant flag blue: ~7.9:1 against dark --paper, no fix needed here */
    --sky-invert: #2a628f; /* the other scheme's --sky; ~5.59:1 against dark-mode --ink used as bg */
  }
}