/* ============================================================
   INTERTrack — Base styles
   Reset, typography, layout primitives
   ============================================================ */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scrollbar-color: var(--border-strong) transparent;
  scrollbar-width: thin;
}

body {
  margin: 0;
  background: var(--bg-base);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: var(--fs-15);
  line-height: 1.6;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background var(--dur-med) var(--ease), color var(--dur-med) var(--ease);
}

/* ── Headings ── */
h1, h2, h3, h4, h5, h6 { margin: 0; color: var(--text-primary); }

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 500;
  letter-spacing: -0.03em;
  line-height: 1.04;
}

h4, h5, h6 {
  font-family: var(--font-sans);
  font-weight: 500;
  line-height: 1.3;
}

h1 { font-size: clamp(44px, 7vw, 88px); }
h2 { font-size: clamp(32px, 5vw, 56px); }
h3 { font-size: clamp(24px, 3vw, 36px); }
h4 { font-size: var(--fs-24); }
h5 { font-size: var(--fs-20); }
h6 { font-size: var(--fs-18); }

p { margin: 0; }
a { color: inherit; text-decoration: none; transition: color var(--dur-fast) var(--ease); }
button { font-family: inherit; background: none; border: 0; padding: 0; cursor: pointer; color: inherit; }
img, svg { display: block; max-width: 100%; }
ul, ol { list-style: none; margin: 0; padding: 0; }
input, textarea, select { font-family: inherit; }

/* ── Layout primitives ── */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--pad-x);
}

.container-md {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 var(--pad-x);
}

.section {
  padding: var(--sp-11) 0;
}

.section-sm {
  padding: var(--sp-9) 0;
}

/* ── Utilities ── */
.mono {
  font-family: var(--font-mono);
  letter-spacing: -0.01em;
}

.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;
}

.text-amber    { color: var(--amber); }
.text-secondary { color: var(--text-secondary); }
.text-success  { color: var(--success); }
.text-danger   { color: var(--danger); }

/* ── Selection ── */
::selection { background: var(--amber); color: var(--amber-on); }

/* ── Focus ── */
:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 2px;
  border-radius: var(--r-xs);
}

/* ── Scroll reveal (set by JS) ── */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--dur-slow) var(--ease-out),
              transform var(--dur-slow) var(--ease-out);
}

.reveal.visible {
  opacity: 1;
  transform: none;
}

.reveal-delay-1 { transition-delay: 80ms; }
.reveal-delay-2 { transition-delay: 160ms; }
.reveal-delay-3 { transition-delay: 240ms; }
.reveal-delay-4 { transition-delay: 320ms; }

/* ── Mobile breakpoints ── */
@media (max-width: 1024px) {
  :root { --pad-x: 24px; }
}

@media (max-width: 768px) {
  :root { --pad-x: 20px; --sp-11: 80px; --sp-9: 64px; }
  h1 { letter-spacing: -0.02em; }
}

@media (max-width: 480px) {
  :root { --pad-x: 16px; }
}