:root {
  /* Surfaces. Light report paper, tinted toward the instrument-blue axis. */
  --bg: oklch(98.5% 0.006 255);
  --bg-elevated: oklch(96.3% 0.009 255);
  --bg-elevated-2: oklch(93.8% 0.012 255);

  /* Text. Ink ladder for long reading and technical scanning. */
  --fg: oklch(18% 0.018 255);
  --fg-secondary: oklch(39% 0.018 255);
  --fg-tertiary: oklch(55% 0.016 255);
  --fg-quaternary: oklch(72% 0.012 255);

  /* Hairlines. Two tiers for report grids and instrument rows. */
  --border: oklch(87.5% 0.012 255);
  --border-bright: oklch(76% 0.02 255);

  /* Single accent. Cobalt remains the only saturated color. */
  --accent: oklch(55% 0.19 256);
  --accent-strong: oklch(49% 0.22 256);
  --accent-deep: oklch(39% 0.19 256);
  --accent-glow: rgba(106, 163, 255, 0.16);
  --accent-glow-soft: rgba(106, 163, 255, 0.06);

  /* Layout */
  --max-w: 1080px;
  --max-w-narrow: 760px;

  /* Motion — one curve, used everywhere. */
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
}