/* =====================================================================
   IPSB — base
   ===================================================================== */
*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: var(--lh);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg, video { max-width: 100%; display: block; }

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-700); }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  color: var(--ink-2);
  font-weight: 500;
  line-height: var(--lh-tight);
  letter-spacing: -.01em;
  margin: 0 0 .5em;
}
h1 { font-size: var(--fs-display); }
h2 { font-size: var(--fs-2xl); }
h3 { font-size: var(--fs-xl); }
h4 { font-size: var(--fs-lg); }

p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

strong, b { font-weight: 700; color: var(--ink-2); }

ul, ol { margin: 0 0 1em; padding-left: 1.25em; }
li + li { margin-top: .35em; }

hr { border: 0; border-top: 1px solid var(--line); margin: var(--sp-6) 0; }

::selection { background: var(--ink); color: #fff; }

:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
  border-radius: var(--r-xs);
}

/* ---- Layout primitives ---- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.container--narrow { max-width: var(--container-narrow); }

.section { padding-block: var(--sp-9); }
.section--tight { padding-block: var(--sp-7); }
.section--alt { background: var(--paper-2); }

/* ---- Text utilities ---- */
.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 500;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--brass);
}
.lede { font-size: var(--fs-md); color: var(--muted); line-height: 1.55; }
.mono { font-family: var(--font-mono); }
.muted { color: var(--muted); }
.center { text-align: center; }

.visually-hidden {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

/* ---- Dark sections ---- */
.surface-dark { background: var(--ink-2); color: var(--on-dark); }
.surface-dark h1, .surface-dark h2, .surface-dark h3, .surface-dark h4 { color: #fff; }
.surface-dark a { color: #fff; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
}