/* ============================================================
   Neural Tech — base / reset / typography / layout primitives
   ============================================================ */

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

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text-300);
  font-family: var(--font-sans);
  font-size: var(--step-0);
  line-height: 1.65;
  font-feature-settings: "ss01", "cv05";
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

/* Ambient dark gradient — evidence/data depth without noise */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(1100px 700px at 78% -8%, rgba(95, 201, 172, 0.10), transparent 60%),
    radial-gradient(900px 620px at 8% 12%, rgba(74, 127, 165, 0.08), transparent 62%),
    radial-gradient(1200px 900px at 50% 108%, rgba(233, 184, 114, 0.06), transparent 60%);
  pointer-events: none;
}

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

h1, h2, h3, h4 {
  font-family: var(--font-serif);
  color: var(--text-100);
  line-height: 1.08;
  letter-spacing: -0.015em;
  font-weight: 500;
  margin: 0 0 0.5em;
  text-wrap: balance;
}
h1 { font-size: var(--step-5); }
h2 { font-size: var(--step-4); }
h3 { font-size: var(--step-2); }
h4 { font-size: var(--step-1); }

p { margin: 0 0 1em; max-width: 68ch; }
p:last-child { margin-bottom: 0; }

a { color: var(--link); text-decoration: none; transition: color var(--dur-fast) var(--ease-out); }
a:hover { color: var(--jade-300); }

strong { color: var(--text-100); font-weight: 600; }

ul, ol { margin: 0 0 1em; padding-left: 1.2em; }
li { margin-bottom: 0.35em; }

/* --- Layout --- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: clamp(1.15rem, 5vw, 2.5rem);
}
.container--narrow { max-width: var(--container-narrow); }

.section { padding-block: var(--section-pad); position: relative; }
.section--tight { padding-block: clamp(2.5rem, 5vw, 4rem); }

/* Connective seam between sections — kills the "disconnected blocks" jank */
.seam { position: relative; }
.seam::before {
  content: "";
  position: absolute;
  top: 0; left: 50%;
  width: 1px; height: var(--space-2xl);
  transform: translate(-50%, -50%);
  background: linear-gradient(to bottom, transparent, var(--jade-400), transparent);
  opacity: 0.5;
}

/* --- Utilities --- */
.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--jade-400);
  display: inline-flex;
  align-items: center;
  gap: 0.6em;
  margin-bottom: var(--space-md);
}
.eyebrow::before {
  content: "";
  width: 1.6rem; height: 1px;
  background: var(--jade-400);
  opacity: 0.6;
}

.lede {
  font-size: var(--step-1);
  color: var(--text-100);
  line-height: 1.55;
  font-weight: 400;
  max-width: 40ch;
}
.muted { color: var(--text-500); }
.text-center { text-align: center; }
.center-block { margin-inline: auto; }
.max-prose { max-width: 60ch; }
.max-prose.center-block { margin-inline: auto; }

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

/* --- Focus (AA) --- */
:where(a, button, input, textarea, select, [tabindex]):focus-visible {
  outline: 3px solid var(--focus-ring);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* Skip link */
.skip-link {
  position: absolute;
  left: var(--space-md); top: -60px;
  z-index: 200;
  background: var(--jade-400);
  color: var(--ink-900);
  padding: 0.7em 1.1em;
  border-radius: var(--radius-sm);
  font-weight: 600;
  transition: top var(--dur-fast) var(--ease-out);
}
.skip-link:focus { top: var(--space-md); color: var(--ink-900); }

/* ============================================================
   Reduced motion — full static fallback (non-negotiable)
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  [data-reveal] { opacity: 1 !important; transform: none !important; }
  .hero__canvas { display: none !important; }
  .hero__fallback { display: block !important; }
}