/* Optia brand tokens (docs/brand/README.md). Four colours, used only at full
   strength and never as tints. Ultraviolet is RGB 72/40/229; the guidelines'
   printed HEX (#3E4899) does not match it or the swatch. */
:root {
  --optia-black: #000000;
  --optia-white: #ffffff;
  --optia-grey: #dadada;
  --optia-ultraviolet: #4828e5;

  /* Borna is the brand face; Trebuchet is the guidelines' system substitute. */
  --optia-font: "Borna", "Trebuchet MS", system-ui, sans-serif;

  --text: var(--optia-black);
  --bg: var(--optia-white);
  --rule: var(--optia-grey);
  --link: var(--optia-ultraviolet);
  --logo-light: block;
  --logo-dark: none;
}

/* Ultraviolet is too dark to read on black, so links turn white. */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --text: var(--optia-white);
    --bg: var(--optia-black);
    --link: var(--optia-white);
    --logo-light: none;
    --logo-dark: block;
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--optia-font);
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
}

a {
  color: var(--link);
  text-underline-offset: 0.15em;
}

/* The logo never goes below the guidelines' 75px minimum width. */
.logo {
  width: 110px;
  min-width: 75px;
  height: auto;
}
.logo-on-light {
  display: var(--logo-light);
}
.logo-on-dark {
  display: var(--logo-dark);
}

/* Large ultraviolet grounds carry the vignette: a 45% black multiply, which
   over a solid colour is the same as darkening it by up to 45%. */
.ultraviolet {
  color: var(--optia-white);
  background-color: var(--optia-ultraviolet);
  background-image: radial-gradient(circle at 25% 70%, rgb(0 0 0 / 0) 0%, rgb(0 0 0 / 0.45) 100%);
}
.ultraviolet a {
  color: var(--optia-white);
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  padding: 1.5rem 1rem;
  font-size: 0.9rem;
  border-top: 1px solid var(--rule);
}

/* Legal pages */
.legal header {
  padding: 1.5rem 1rem;
  border-bottom: 1px solid var(--rule);
}
.legal header,
.legal main,
.legal .site-footer {
  max-width: 46rem;
  margin: 0 auto;
}
.legal main {
  padding: 2rem 1rem 3rem;
}
.legal h1 {
  font-size: 2.25rem;
  line-height: 1.15;
  margin: 0 0 0.25rem;
}
.legal h2 {
  font-size: 1.2rem;
  margin: 2rem 0 0.5rem;
}
.legal .updated {
  margin-top: 0;
  font-weight: 600;
}
.draft {
  color: var(--optia-black);
  background: var(--optia-grey);
  padding: 0.75rem 1rem;
}