/* intell-write — marketing site. Minimal, airy, focused. */
:root {
  --ink: #242833;
  --muted: #6b7286;
  --accent: #3730a3; /* dark indigo — primary */
  --accent-hover: #312e81;
  --paper: #f8f9fb;
  --edge: #e4e6ec;
  --expand: #3730a3; /* additions */
  --condense: #e11d48; /* cuts */
  --simplify: #059669; /* reworded */
  --maxw: 1080px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

a { color: inherit; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 1.5rem; }

/* ---------- header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: saturate(1.1) blur(8px);
  background: color-mix(in srgb, var(--paper) 82%, transparent);
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}
.site-header.scrolled { border-bottom-color: var(--edge); }
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.brand {
  font-weight: 650;
  letter-spacing: -0.02em;
  text-decoration: none;
  font-size: 1.05rem;
}
.brand .dot { color: var(--accent); }
.nav { display: flex; align-items: center; gap: 1.25rem; }
/* Exclude .btn so the header's "Open the app" button keeps its own colours
   (otherwise .nav a would out-specify .btn-primary and grey out its text). */
.nav a:not(.btn) { color: var(--muted); text-decoration: none; font-size: 0.9rem; }
.nav a:not(.btn):hover { color: var(--ink); }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  border-radius: 10px;
  padding: 0.7rem 1.15rem;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, transform 0.1s;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-hover); }
.btn-ghost { border-color: var(--edge); color: var(--ink); background: #fff; }
.btn-ghost:hover { border-color: var(--muted); }
.btn-sm { padding: 0.5rem 0.9rem; font-size: 0.875rem; }

/* ---------- hero ---------- */
.hero {
  position: relative;
  min-height: min(90vh, 780px);
  display: flex;
  align-items: center;
  overflow: hidden;
  background: #e9ebef; /* light grey */
  border-bottom: 1px solid var(--edge);
}
#hero-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
}
.hero-inner {
  position: relative;
  z-index: 2;
  padding: 5rem 0;
  max-width: 40rem;
}
/* Soft light scrim so the flowing text never fights the copy. It spans the whole
   hero and fades to fully transparent well inside it, so there is no opaque edge
   for `overflow: hidden` to clip into a hard line. Sits above the canvas
   (z-index 1) but below the copy (hero-inner z-index 2). */
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background: radial-gradient(
    115% 95% at 18% 50%,
    rgba(233, 235, 239, 0.92) 0%,
    rgba(233, 235, 239, 0.78) 24%,
    rgba(233, 235, 239, 0) 58%
  );
}
.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--accent);
  margin: 0 0 1rem;
}
.hero h1 {
  font-size: clamp(2.2rem, 5.2vw, 3.6rem);
  line-height: 1.05;
  letter-spacing: -0.03em;
  font-weight: 700;
  color: var(--ink);
  margin: 0 0 1.1rem;
}
.hero p.lead {
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--muted);
  margin: 0 0 2rem;
  max-width: 34rem;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 0.75rem; }

/* ---------- sections ---------- */
section { padding: 5.5rem 0; }
.section-head { max-width: 42rem; margin: 0 auto 3rem; text-align: center; }
.section-head .kicker {
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--accent);
  margin: 0 0 0.75rem;
}
.section-head h2 {
  font-size: clamp(1.6rem, 3.4vw, 2.3rem);
  letter-spacing: -0.02em;
  margin: 0 0 0.75rem;
}
.section-head p { color: var(--muted); margin: 0; font-size: 1.05rem; }

/* selling points — horizontal */
.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}
.feature {
  background: #fff;
  border: 1px solid var(--edge);
  border-radius: 16px;
  padding: 1.75rem;
}
.feature .num {
  font-variant-numeric: tabular-nums;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.1em;
}
.feature h3 { margin: 0.75rem 0 0.5rem; font-size: 1.15rem; letter-spacing: -0.01em; }
.feature p { margin: 0; color: var(--muted); font-size: 0.95rem; }

/* descriptive / science section */
.prose-section { background: #fff; border-top: 1px solid var(--edge); border-bottom: 1px solid var(--edge); }
.prose-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: start;
}
.prose-grid h2 { font-size: clamp(1.5rem, 3vw, 2rem); letter-spacing: -0.02em; margin: 0 0 1rem; }
.prose-grid h3 { font-size: 1.1rem; margin: 0 0 0.6rem; }
.prose-grid p { color: var(--muted); margin: 0 0 1rem; }
.prose-grid .card {
  background: var(--paper);
  border: 1px solid var(--edge);
  border-radius: 16px;
  padding: 1.75rem;
}
.cite {
  font-size: 0.85rem;
  color: var(--muted);
  font-style: italic;
  border-top: 1px solid var(--edge);
  padding: 0.9rem 0 0;
  margin-top: 1.25rem;
}
.cite a { color: var(--accent); }

/* CTA band */
.cta {
  text-align: center;
}
.cta h2 { font-size: clamp(1.6rem, 3.4vw, 2.2rem); letter-spacing: -0.02em; margin: 0 0 1.5rem; }

/* ---------- footer ---------- */
.site-footer {
  border-top: 1px solid var(--edge);
  background: #fff;
  padding: 3rem 0;
}
.site-footer .wrap {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  align-items: center;
  justify-content: space-between;
}
.footer-links { display: flex; flex-wrap: wrap; gap: 1.25rem; }
.footer-links a { color: var(--muted); text-decoration: none; font-size: 0.9rem; }
.footer-links a:hover { color: var(--ink); }
.footer-meta { color: var(--muted); font-size: 0.85rem; }

/* ---------- legal / content pages ---------- */
.page { padding: 4rem 0 5rem; }
.page .wrap { max-width: 760px; }
.page h1 { font-size: 2rem; letter-spacing: -0.02em; margin: 0 0 0.5rem; }
.page h2 { font-size: 1.3rem; margin: 2.5rem 0 0.75rem; letter-spacing: -0.01em; }
.page h3 { font-size: 1.05rem; margin: 1.5rem 0 0.5rem; }
.page p, .page li { color: #3a3f4d; }
.page a { color: var(--accent); }
.page .updated { color: var(--muted); font-size: 0.9rem; }
.page .placeholder {
  background: #fff7ed;
  border: 1px dashed #fdba74;
  color: #9a3412;
  border-radius: 4px;
  padding: 0.05rem 0.35rem;
  font-size: 0.9em;
}
.lang-sep { border: 0; border-top: 1px solid var(--edge); margin: 3.5rem 0; }
.back-link { display: inline-block; margin-bottom: 1.5rem; color: var(--muted); text-decoration: none; font-size: 0.9rem; }
.back-link:hover { color: var(--ink); }

/* ---------- responsive ---------- */
@media (max-width: 860px) {
  .features { grid-template-columns: 1fr; }
  .prose-grid { grid-template-columns: 1fr; gap: 2rem; }
  .nav a:not(.btn) { display: none; }
}