/* ============================================================
   BASE — light element resets bound to the token layer.
   Not a CSS reset library; just enough to make the tokens
   render correctly anywhere the stylesheet is linked.
   ============================================================ */

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

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: var(--lh-normal);
  color: var(--text-primary);
  background: var(--surface-page);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* Display / heading defaults — sentence case, tight tracking */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: var(--fw-bold);
  letter-spacing: var(--ls-heading);
  line-height: var(--lh-snug);
  margin: 0;
}

/* Emphasis convention: italic marks the key phrase in a headline */
h1 em, h2 em, h3 em {
  font-style: italic;
  font-weight: inherit;
}

a {
  color: var(--text-accent);
  text-decoration: none;
}

/* Section marker / eyebrow — wide-tracked uppercase (the "§ 01 —" device) */
.ff-overline {
  font-size: var(--fs-overline);
  letter-spacing: var(--ls-overline);
  text-transform: uppercase;
  font-weight: var(--fw-medium);
  color: var(--text-secondary);
}

/* Part numbers / standards — the only sanctioned all-caps, set in mono */
.ff-partno {
  font-family: var(--font-mono);
  letter-spacing: var(--ls-mono);
  text-transform: uppercase;
}

/* Watermark helper (brand book §04 — always 30%) */
.ff-watermark {
  opacity: var(--watermark-opacity);
  pointer-events: none;
  user-select: none;
}

::selection {
  background: var(--accent);
  color: var(--accent-contrast);
}