/*
 * "Deep Field" - the INDIkit documentation palette.
 *
 * Anchored on two points of the viridis colormap, #463480 (0.15) and #3b528b
 * (0.25), because those are the violets an astronomer has already looked at ten
 * thousand times in a science plot. Kept muted and low-chroma on purpose: it
 * should read as deep sky, not as a neon gradient.
 *
 * WHY THIS FILE EXISTS AT ALL, and why `primary: custom` in mkdocs.yml is not
 * enough on its own. Material ships a `[data-md-color-primary=<name>]` rule per
 * built-in colour; there is no `custom` rule in palette.css, so the attribute
 * mkdocs.yml emits matches nothing shipped and every variable below is ours to
 * set. `extra_css` loads after the theme's own stylesheets, so these win.
 *
 * The trap is `--md-typeset-a-color`. Material sets it to
 * `var(--md-primary-fg-color)` for both schemes, then ships 13 light-mode and 9
 * slate-mode per-colour overrides precisely because a primary dark enough for
 * the header is the wrong lightness for body links in one scheme or the other.
 * `custom` inherits NONE of those overrides, so a link would come out #3a2a70
 * in slate: dark violet on a near-black page. It has to be set per scheme, and
 * that is what the last two rules do. `--md-primary-bg-color` has the same
 * shape of problem, defaulting to #fff from `:root` no matter how light the
 * primary is, so it is set explicitly rather than left to luck.
 *
 * Measured contrast ratios (WCAG 2.x, sRGB). Do not "tidy" a value without
 * re-measuring - the palette this replaced looked fine and failed AA outright
 * (its light link was 2.78:1, below even the 3:1 large-text floor).
 *
 *   header text  #ffffff on #3a2a70   12.03:1   AAA
 *   light link   #4b3a91 on #ffffff    9.08:1   AAA  (8.33:1 on #f5f5f5 code)
 *   light accent #0f7f96 on #ffffff    4.67:1   AA
 *   slate link   #a99ae4 on #221e29    6.56:1   AAA  (5.82:1 on #2c2735 code)
 *   slate accent #38bcd6 on #221e29    7.26:1   AAA
 */

[data-md-color-primary="custom"] {
  --md-primary-fg-color: #3a2a70;
  --md-primary-fg-color--light: #584499;
  --md-primary-fg-color--dark: #241a48;
  --md-primary-bg-color: #ffffff;
  --md-primary-bg-color--light: #ffffffb3;
}

[data-md-color-accent="custom"] {
  --md-accent-fg-color: #0f7f96;
  --md-accent-fg-color--transparent: #0f7f961a;
}

/*
 * Per-scheme link and accent colours. These have the same specificity as the
 * `custom` rules above and must stay after them, or the slate overrides lose.
 */
[data-md-color-scheme="default"] {
  --md-typeset-a-color: #4b3a91;
}

[data-md-color-scheme="slate"] {
  /*
   * Tint the whole slate surface ramp toward the palette. Material derives every
   * slate surface from `hsla(var(--md-hue), ...)`, so this one line moves the page
   * background from #1e2129 to #221e29 and carries the rest with it. Body-text
   * contrast is unchanged (8.94:1 -> 8.97:1) and the link and accent ratios above
   * are quoted against the tinted background.
   */
  --md-hue: 262deg;

  --md-typeset-a-color: #a99ae4;
  --md-accent-fg-color: #38bcd6;
}