/* ==========================================================================
   Base — reset + typography + Bootstrap 5.3 grid integration.
   We use only Bootstrap's grid utilities (container/row/col) and reset chrome
   to match the deep-tech aesthetic.
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: "ss01", "cv11", "ss03"; /* Inter stylistic sets for refined glyphs */
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  -webkit-tap-highlight-color: transparent;
}

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

body {
  margin: 0;
  background-color: var(--surface-base);
  color: var(--ink-primary);
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  letter-spacing: var(--tracking-body);
  font-synthesis: none;
  overflow-x: hidden;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main { flex: 1 0 auto; }

::selection {
  background: var(--selection-bg);
  color: var(--selection-fg);
}

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

a {
  color: inherit;
  text-decoration: underline;
  text-decoration-color: var(--border-strong);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
  transition: text-decoration-color var(--t-fast) var(--ease-out),
              color var(--t-fast) var(--ease-out);
}
a:hover { text-decoration-color: var(--accent); }
a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: var(--radius-1);
}

/* ----- Headings ----- */
h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--s-4) 0;
  font-family: var(--font-sans);
  font-weight: var(--weight-semibold);
  line-height: var(--lh-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--ink-primary);
  text-wrap: balance;
}
h1 { font-size: var(--fs-h1); font-weight: var(--weight-bold); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); }
h4 { font-size: var(--fs-h4); }

p {
  margin: 0 0 var(--s-4) 0;
  text-wrap: pretty;
}

/* ----- Display utilities ----- */
.display-1 {
  font-size: var(--fs-display-1);
  line-height: var(--lh-display);
  letter-spacing: var(--tracking-display);
  font-weight: var(--weight-bold);
  margin: 0;
}
.display-2 {
  font-size: var(--fs-display-2);
  line-height: var(--lh-display);
  letter-spacing: var(--tracking-display);
  font-weight: var(--weight-bold);
  margin: 0;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  font-weight: var(--weight-medium);
  text-transform: uppercase;
  letter-spacing: var(--tracking-eyebrow);
  color: var(--ink-muted);
  display: inline-block;
}

.serif { font-family: var(--font-serif); letter-spacing: 0; }
.mono  { font-family: var(--font-mono);  letter-spacing: 0; }

.text-muted   { color: var(--ink-muted); }
.text-secondary { color: var(--ink-secondary); }
.text-balance { text-wrap: balance; }
.text-pretty  { text-wrap: pretty; }

/* ----- Long-form prose (research articles, trust-layer essay) ----- */
.prose {
  font-family: var(--font-serif);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  letter-spacing: 0;
  color: var(--ink-primary);
  max-width: var(--reading-max);
}
.prose h2, .prose h3, .prose h4 {
  font-family: var(--font-sans);
  letter-spacing: var(--tracking-heading);
  margin-top: var(--s-7);
  margin-bottom: var(--s-3);
}
.prose h2 { font-size: var(--fs-h2); }
.prose h3 { font-size: var(--fs-h3); }
.prose h4 { font-size: var(--fs-h4); }
.prose p  { margin: 0 0 var(--s-4) 0; }
.prose strong { font-weight: var(--weight-semibold); }
.prose blockquote {
  margin: var(--s-5) 0;
  padding-left: var(--s-4);
  border-left: 2px solid var(--accent);
  font-style: italic;
  color: var(--ink-secondary);
}
.prose ul, .prose ol { padding-left: var(--s-5); margin: 0 0 var(--s-4); }
.prose li { margin-bottom: var(--s-2); }
.prose hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: var(--s-7) 0;
}
.prose a {
  text-decoration-color: var(--accent);
  text-decoration-thickness: 1.5px;
}
.prose img, .prose figure {
  margin: var(--s-5) 0;
}
.prose figcaption {
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  color: var(--ink-muted);
  margin-top: var(--s-2);
}
.prose code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  background: var(--surface-elevated);
  padding: 0.12em 0.36em;
  border-radius: var(--radius-1);
  border: 1px solid var(--border);
}
.prose pre {
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  background: var(--surface-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-1);
  padding: var(--s-4);
  margin: var(--s-5) 0;
  overflow-x: auto;
  line-height: 1.55;
}
.prose pre code {
  background: transparent;
  border: 0;
  padding: 0;
}
.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--s-5) 0;
  font-family: var(--font-sans);
  font-size: var(--fs-small);
}
.prose th, .prose td {
  text-align: left;
  padding: var(--s-2) var(--s-3);
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
.prose th {
  font-weight: var(--weight-semibold);
  color: var(--ink-primary);
  border-bottom-color: var(--border-strong);
}

/* ----- Page layout primitives ----- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.container-narrow {
  width: 100%;
  max-width: var(--container-narrow);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.container-reading {
  width: 100%;
  max-width: var(--reading-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.full-bleed {
  width: 100vw;
  margin-inline: calc(50% - 50vw);
}

.section {
  padding-block: clamp(var(--s-7), 8vw, var(--s-10));
}
.section-tight {
  padding-block: clamp(var(--s-6), 6vw, var(--s-8));
}

.divider {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 0;
}
.divider-strong {
  border: 0;
  border-top: 1px solid var(--border-strong);
  margin: 0;
}

/* ----- Skip link for accessibility ----- */
.skip-link {
  position: absolute;
  left: var(--s-4);
  top: var(--s-4);
  z-index: var(--z-toast);
  padding: var(--s-2) var(--s-4);
  background: var(--ink-primary);
  color: var(--surface-base);
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  text-decoration: none;
  transform: translateY(-200%);
  transition: transform var(--t-fast) var(--ease-out);
}
.skip-link:focus {
  transform: translateY(0);
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

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

/* ----- Reveal on scroll: applied via IntersectionObserver in core.js ----- */
[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity var(--t-slow) var(--ease-out),
              transform var(--t-slow) var(--ease-out);
  will-change: opacity, transform;
}
[data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}
@media (prefers-reduced-motion: reduce) {
  [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* ----- Utility: stagger reveal child indices for cascading animations ----- */
[data-stagger] > * { transition-delay: calc(var(--stagger-index, 0) * 60ms); }

/* ----- Bootstrap grid integration ----- */
.row { --bs-gutter-x: var(--s-5); }