/* Design tokens. Every colour, size and timing used on the site is declared
   here — nothing below this file should contain a raw hex value. */

:root {
  /* Colour. Two hues only: a light blue ground and white surfaces. */
  --paper:      #e3edf7;
  --paper-sink: #d7e6f3;
  --surface:    #ffffff;
  --line:       #c8dcec;
  --line-strong:#b0cee6;
  --line-soft:  #d9e8f3;
  --blue:       #2f83bf;
  --blue-deep:  #0d4b76;
  --ink:        #10222e;
  --ink-soft:   #4d6675;
  --ink-faint:  #7b94a5;

  /* Type. No web fonts — the display face is the monospace already on the
     machine, which suits the subject and costs nothing to load. */
  --font-body: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;

  --text-xs:   0.75rem;
  --text-sm:   0.875rem;
  --text-base: 1.0625rem;
  --text-md:   1.1875rem;
  --text-lg:   1.4rem;
  --text-xl:   clamp(1.6rem, 3.2vw, 2.1rem);
  --text-2xl:  clamp(2.1rem, 6.2vw, 3.6rem);

  --tracking-label: 0.16em;
  --tracking-tight: -0.02em;

  /* Space */
  --s-1: 0.35rem;
  --s-2: 0.6rem;
  --s-3: 1rem;
  --s-4: 1.5rem;
  --s-5: 2.25rem;
  --s-6: 3.25rem;
  --s-7: clamp(3.5rem, 8vw, 6rem);

  /* Shape. The lifts are barely-there — enough to separate a white surface
     from the light blue ground, not enough to read as a drop shadow. */
  --radius-sm: 5px;
  --radius:    9px;
  --radius-lg: 14px;
  --lift:      0 1px 2px color-mix(in srgb, var(--blue-deep) 8%, transparent);
  --lift-high: 0 10px 26px color-mix(in srgb, var(--blue-deep) 14%, transparent);

  /* Layout */
  --shell:   68rem;
  --measure: 40rem;
  --gutter:  clamp(1.25rem, 4vw, 2.5rem);
  --rail:    7.5rem;   /* width of the label rail beside each section */
  --header:  4.25rem;

  /* Motion */
  --ease:      cubic-bezier(0.2, 0.7, 0.2, 1);
  --ease-out:  cubic-bezier(0.16, 1, 0.3, 1);
  --t-fast:    130ms;
  --t-mid:     280ms;
  --t-slow:    620ms;
}

@media (max-width: 60rem) {
  :root {
    --rail: 0rem;
    --header: 3.75rem;
  }
}