/* ============================================================
   AtlasML — Design tokens, type, base reset
   Bold editorial: black canvas, ivory ink, electric-lime accent.
   ============================================================ */

:root {
  /* Palette — dark default */
  --bg:        #0A0A0A;
  --bg-1:     #111111;
  --bg-2:     #161616;
  --ink:       #F4F1EA;   /* warm ivory */
  --ink-1:     #C9C4B9;
  --ink-2:     #8B8679;
  --ink-3:     #5A554A;
  --accent:    #4F7CFF;   /* trust blue — modern AI */
  --accent-ink:#FFFFFF;
  --line:      rgba(244, 241, 234, 0.10);
  --line-2:    rgba(244, 241, 234, 0.18);
  --danger:    #FF6A3D;

  /* Type */
  --f-serif: "Instrument Serif", "Newsreader", ui-serif, Georgia, serif;
  --f-sans:  "Geist", "DM Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --f-mono:  "JetBrains Mono", "Geist Mono", ui-monospace, "SF Mono", Menlo, monospace;

  /* Scale */
  --t-mono-xs: 11px;
  --t-mono-sm: 12px;
  --t-body-sm: 14px;
  --t-body:    16px;
  --t-body-lg: 18px;
  --t-lead:    22px;

  /* Editorial display steps */
  --t-d-xs: clamp(28px, 3vw, 40px);
  --t-d-sm: clamp(40px, 5vw, 64px);
  --t-d-md: clamp(56px, 7vw, 96px);
  --t-d-lg: clamp(72px, 11vw, 168px);

  /* Rhythm */
  --pad-x: clamp(20px, 5vw, 80px);
  --gap:   24px;
  --rad:   2px;     /* editorial: minimal radii */
  --rad-pill: 999px;

  /* Motion */
  --ease: cubic-bezier(.2,.7,.2,1);
}

html[data-theme="light"] {
  --bg:        #F4F1EA;
  --bg-1:     #ECE8DE;
  --bg-2:     #E2DDD0;
  --ink:       #0A0A0A;
  --ink-1:     #2A2A2A;
  --ink-2:     #6B6B6B;
  --ink-3:     #9A968B;
  --line:      rgba(10, 10, 10, 0.10);
  --line-2:    rgba(10, 10, 10, 0.18);
}

/* Reset-ish */
*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; overflow-x: hidden; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--f-sans);
  font-size: var(--t-body);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  transition: background-color .4s var(--ease), color .4s var(--ease);
  overflow-x: hidden;
}
img, svg { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
input, textarea, select { font: inherit; color: inherit; }

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

/* Headings — editorial serif, tight tracking, allow italics to breathe */
h1, h2, h3, h4 {
  font-family: var(--f-serif);
  font-weight: 400;
  line-height: 0.98;
  letter-spacing: -0.02em;
  margin: 0;
  text-wrap: balance;
}
h1 em, h2 em, h3 em, h4 em { font-style: italic; color: var(--ink-2); }

p { margin: 0; text-wrap: pretty; }

/* Utility */
.mono {
  font-family: var(--f-mono);
  font-size: var(--t-mono-sm);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-2);
}
.mono--accent { color: var(--accent); }
.mono--ink    { color: var(--ink); }

.eyebrow {
  font-family: var(--f-mono);
  font-size: var(--t-mono-sm);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-2);
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.eyebrow::before {
  content: "";
  width: 28px;
  height: 1px;
  background: var(--accent);
}

/* Layout containers */
.wrap {
  width: 100%;
  max-width: 1480px;
  margin: 0 inline-auto;
  margin-inline: auto;
  padding-inline: var(--pad-x);
}

section { padding-block: clamp(80px, 9vw, 160px); position: relative; }
section + section { border-top: 1px solid var(--line); }

.section-head {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-bottom: clamp(40px, 5vw, 72px);
}
@media (min-width: 900px) {
  .section-head { grid-template-columns: 0.45fr 0.55fr; align-items: end; gap: 48px; }
}
.section-head h2 { font-size: var(--t-d-md); }
.section-head .section-sub {
  color: var(--ink-1);
  font-size: var(--t-lead);
  max-width: 56ch;
  line-height: 1.4;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 22px;
  font-family: var(--f-mono);
  font-size: var(--t-mono-sm);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  border-radius: var(--rad-pill);
  transition: transform .3s var(--ease), background .3s var(--ease), color .3s var(--ease), border-color .3s var(--ease);
  white-space: nowrap;
  border: 1px solid var(--line-2);
}
.btn:hover { transform: translateY(-2px); }
.btn--accent { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.btn--accent:hover { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.btn--ghost  { background: transparent; color: var(--ink); }
.btn--ghost:hover { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.btn--ink { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.btn--ink:hover { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.btn .arrow { width: 14px; height: 14px; }

/* Reveal animation */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity .9s var(--ease), transform .9s var(--ease); }
.reveal.is-in { opacity: 1; transform: translateY(0); }
.reveal[data-delay="1"] { transition-delay: .08s; }
.reveal[data-delay="2"] { transition-delay: .16s; }
.reveal[data-delay="3"] { transition-delay: .24s; }
.reveal[data-delay="4"] { transition-delay: .32s; }
.reveal[data-delay="5"] { transition-delay: .40s; }
.reveal[data-delay="6"] { transition-delay: .48s; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  * { animation: none !important; transition-duration: .01ms !important; }
}

/* Skip link */
.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;
}
.skip-link {
  position: fixed; top: 8px; left: 8px; z-index: 1000;
  background: var(--accent); color: var(--accent-ink);
  padding: 10px 16px; transform: translateY(-200%);
  transition: transform .2s var(--ease);
  font-family: var(--f-mono); font-size: var(--t-mono-sm); text-transform: uppercase;
}
.skip-link:focus { transform: translateY(0); }