/* Purified HVAC · reset, typography, layout primitives (v2) */

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

html {
  -webkit-text-size-adjust: 100%;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: var(--step-0);
  line-height: 1.55;
  font-feature-settings: "ss01", "cv11";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img, svg, video, canvas, picture {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: var(--ink-900);
  text-decoration: underline;
  text-decoration-color: var(--ink-300);
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
  transition: text-decoration-color var(--dur-1) var(--ease-out), color var(--dur-1) var(--ease-out);
}
a:hover { text-decoration-color: var(--brick-600); }

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

/* Display headings: weight + tight tracking. Not oversized. */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--ink-900);
  margin: 0;
  text-wrap: balance;
}

h1 {
  font-size: var(--step-5);
  line-height: 1.04;
  letter-spacing: -0.025em;
  font-weight: 600;
}
h2 {
  font-size: var(--step-4);
  line-height: 1.08;
  letter-spacing: -0.022em;
}
h3 {
  font-size: var(--step-3);
  line-height: 1.18;
  letter-spacing: -0.018em;
}
h4 {
  font-size: var(--step-1);
  line-height: 1.3;
  letter-spacing: -0.008em;
  font-weight: 600;
}

p { margin: 0; max-width: var(--measure); color: var(--ink-800); }
p + p { margin-top: var(--space-4); }

ul, ol { padding-left: 1.1em; margin: 0; }
li + li { margin-top: var(--space-2); }
li::marker { color: var(--ink-400); }

small, .micro {
  font-size: var(--step--1);
  color: var(--ink-500);
  letter-spacing: 0.01em;
}

::selection { background: var(--ink-900); color: var(--paper); }

/* Layout primitives */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: clamp(20px, 4vw, 40px);
}

.section {
  padding-block: clamp(56px, 9vw, var(--space-9));
}
.section--tight { padding-block: clamp(40px, 6vw, 72px); }
.section--lg    { padding-block: clamp(80px, 12vw, var(--space-10)); }

.section--warm   { background: var(--surface-tinted); }
.section--ink    { background: var(--ink-900); color: var(--paper); }
.section--ink h1, .section--ink h2, .section--ink h3 { color: var(--paper); }

.stack > * + * { margin-top: var(--space-5); }
.stack-sm > * + * { margin-top: var(--space-3); }
.stack-lg > * + * { margin-top: var(--space-6); }

/* Eyebrow: small uppercase label, ink (not colored), restrained */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono), var(--font-sans);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-500);
}
.eyebrow::before {
  content: "";
  width: 14px; height: 1px;
  background: var(--ink-300);
}

.lead {
  font-size: var(--step-1);
  line-height: 1.45;
  color: var(--ink-700);
  max-width: 60ch;
}

.muted { color: var(--ink-700); }

.divider {
  height: 1px;
  background: var(--hairline);
  border: 0;
}

/* Skip link */
.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--ink-900);
  color: var(--paper);
  padding: 10px 14px;
  border-radius: 0 0 6px 0;
  z-index: 100;
}
.skip:focus { left: 0; }

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