/* Design tokens — the one place colors, type, and motion are defined.
   Loaded by the Jekyll site AND by the standalone pages (letting-go.html, brainstorm_bci_blog.html,
   growlab/), so everything reads as one system. Plain CSS on purpose: GitHub Pages' Ruby Sass 3.7
   cannot compile clamp()/min() with mixed units.

   Theming: every color is a light-dark() pair. color-scheme decides which half applies, and
   [data-theme] (set by the inline script in _includes/head.html) overrides the OS preference. */

:root {
  color-scheme: light dark;

  /* surfaces */
  --bg:          light-dark(#f8f7f4, #0a0a0c);
  --bg-raised:   light-dark(#ffffff, #121216);
  --bg-sunken:   light-dark(#efede8, #060608);
  --bg-hover:    light-dark(#f2f0eb, #17171c);

  /* text */
  --fg:          light-dark(#16161a, #ececef);
  --fg-2:        light-dark(#45454e, #b0b0b9);
  --fg-3:        light-dark(#6b6b75, #85858f);

  /* lines */
  --line:        light-dark(rgba(22, 22, 26, 0.09), rgba(255, 255, 255, 0.075));
  --line-strong: light-dark(rgba(22, 22, 26, 0.17), rgba(255, 255, 255, 0.14));

  /* accent: gold, carried over from the old editorial theme */
  --accent:      light-dark(#8f5f00, #e3b55a);
  --accent-2:    light-dark(#b07a12, #f2cd80);
  --accent-ink:  light-dark(#ffffff, #1b1407);
  --accent-soft: light-dark(rgba(143, 95, 0, 0.08), rgba(227, 181, 90, 0.11));
  --glow:        light-dark(rgba(214, 160, 40, 0.20), rgba(227, 181, 90, 0.14));
  /* secondary signal color, used sparingly (connectome spikes, charts) */
  --signal:      light-dark(#1f7a72, #5fd3c6);
  --signal-soft: light-dark(rgba(31, 122, 114, 0.10), rgba(95, 211, 198, 0.12));

  --shadow-color: light-dark(rgba(24, 22, 18, 0.08), rgba(0, 0, 0, 0.55));
  --shadow-sm: 0 1px 2px var(--shadow-color);
  --shadow:    0 1px 2px var(--shadow-color), 0 12px 32px -12px var(--shadow-color);
  --shadow-lg: 0 2px 4px var(--shadow-color), 0 28px 64px -24px var(--shadow-color);

  /* type */
  --font-sans:  "Geist", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-serif: "Instrument Serif", ui-serif, Georgia, "Times New Roman", serif;
  --font-mono:  "Geist Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;

  --text-xs:   0.75rem;
  --text-sm:   0.875rem;
  --text-base: 1rem;
  --text-prose: 1.0625rem;
  --text-lg:   clamp(1.125rem, 1.05rem + 0.3vw, 1.25rem);
  --text-xl:   clamp(1.35rem, 1.2rem + 0.6vw, 1.65rem);
  --text-2xl:  clamp(1.75rem, 1.35rem + 1.5vw, 2.5rem);
  --text-3xl:  clamp(2.25rem, 1.55rem + 2.9vw, 3.75rem);
  --text-hero: clamp(2.9rem, 1.4rem + 6vw, 6.25rem);

  --leading-tight: 1.08;
  --leading-snug:  1.3;
  --leading:       1.65;
  --tracking-tight: -0.035em;
  --tracking-mono:  0.02em;

  /* layout */
  --max:     74rem;
  --prose:   42rem;
  --gutter:  clamp(1.25rem, 4vw, 2.5rem);
  --section: clamp(4.5rem, 3rem + 6vw, 9rem);
  --header-h: 4rem;

  --radius-sm:   8px;
  --radius:      14px;
  --radius-lg:   22px;
  --radius-pill: 999px;

  /* motion */
  --ease-out:    cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
  --dur-fast: 160ms;
  --dur:      320ms;
  --dur-slow: 700ms;
}

:root[data-theme="light"] { color-scheme: light; }
:root[data-theme="dark"]  { color-scheme: dark; }