/* BVS — corporate site.
   Colour: three palette inputs (--light, --dark, --accent). Everything else is derived from them,
   so a palette swap is three values. Palette "Ultramarine" (approved 2026-11-13): porcelain, carbon,
   ultramarine. Reference with CMYK pairs: branding-area/palette.html.
   html[data-band="accent"] (set in index.html) paints the contact band in the accent;
   html[data-mode="dark"] flips the page to the dark neutral (not used). */

:root {
  /* palette inputs */
  --light: #e8ebed;
  --dark: #17191d;
  --accent: #244cff;
  --accent-ink: var(--accent);   /* accent safe for text on --bg: 4.9:1 */
  --on-accent: #ffffff;         /* text on an accent fill: 5.9:1 */
  --code-key: color-mix(in srgb, var(--accent) 45%, #fff);  /* accent readable on dark panels */

  /* page */
  --bg: var(--light);
  --text: var(--dark);
  --paper: #ffffff;
  --shade: var(--dark);

  /* derived neutrals */
  --surface: color-mix(in srgb, var(--text) 4%, var(--bg));
  --sub: var(--surface);
  --sub-2: color-mix(in srgb, var(--text) 8%, var(--bg));
  --base: color-mix(in srgb, var(--paper) 55%, var(--bg));
  --line: color-mix(in srgb, var(--text) 11%, var(--bg));
  --mid: color-mix(in srgb, var(--text) 18%, var(--bg));
  --faint: color-mix(in srgb, var(--text) 42%, var(--bg));
  --muted: color-mix(in srgb, var(--text) 68%, var(--bg));
  --ink-2: color-mix(in srgb, var(--text) 80%, var(--bg));
  --accent-hover: color-mix(in srgb, var(--accent) 82%, var(--dark));

  /* dark panels: code views, footer */
  --code-bg: var(--dark);
  --code-fg: color-mix(in srgb, var(--light) 86%, var(--code-bg));
  --code-val: var(--light);
  --code-dim: color-mix(in srgb, var(--light) 60%, var(--code-bg));
  --foot-bg: var(--dark);

  /* contact band */
  --band: var(--dark);
  --band-fg: var(--light);
  --band-soft: color-mix(in srgb, var(--band-fg) 74%, var(--band));
  --band-muted: color-mix(in srgb, var(--band-fg) 54%, var(--band));
  --band-line: color-mix(in srgb, var(--band-fg) 13%, var(--band));

  --wrap: 1200px;
  --gutter: clamp(16px, 4vw, 48px);
  --section: clamp(88px, 11vw, 150px);

  /* one grotesque for everything (decided 2026-11-14): Inter, no serif pairing */
  --sans: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, "Cascadia Mono", Consolas, monospace;
}

html[data-mode="dark"] {
  --bg: var(--dark);
  --text: var(--light);
  --paper: color-mix(in srgb, var(--light) 9%, var(--dark));
  --shade: #000;
  --base: color-mix(in srgb, var(--light) 3%, var(--dark));
  --surface: color-mix(in srgb, var(--light) 5%, var(--dark));
  --code-bg: color-mix(in srgb, #000 38%, var(--dark));
  --foot-bg: color-mix(in srgb, #000 38%, var(--dark));
  --band: color-mix(in srgb, #000 38%, var(--dark));
  color-scheme: dark;
}
html[data-band="accent"] {
  --band: var(--accent);
  --band-fg: var(--on-accent);
  --band-soft: color-mix(in srgb, var(--band-fg) 90%, var(--band));
  --band-muted: color-mix(in srgb, var(--band-fg) 78%, var(--band));
  --band-line: color-mix(in srgb, var(--band-fg) 24%, var(--band));
}

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

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3 { margin: 0; font-weight: 400; }
h1, h2 { font-weight: 600; letter-spacing: -0.025em; line-height: 1.06; }
h2 { font-size: clamp(34px, 4.4vw, 60px); max-width: 18ch; }
h3 { font-family: var(--sans); font-size: 20px; font-weight: 500; letter-spacing: -0.01em; line-height: 1.3; }
p { margin: 0; }
a { color: inherit; text-decoration: none; }
em { font-style: italic; color: var(--accent-ink); }

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 var(--gutter); }
.eyebrow {
  font-size: 13px; font-weight: 500; letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--muted); margin-bottom: 24px;
}
.lead { font-size: clamp(18px, 1.5vw, 21px); color: var(--muted); max-width: 44ch; }
.num { font-weight: 500; font-size: 15px; color: var(--accent-ink); font-variant-numeric: lining-nums tabular-nums; }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  height: 48px; padding: 0 24px; border-radius: 999px;
  background: var(--text); color: var(--bg);
  font-weight: 500; font-size: 15px;
  transition: background-color .15s ease, color .15s ease;
  white-space: nowrap;
}
.btn:hover { background: var(--accent); color: var(--on-accent); }
.btn--sm { height: 38px; padding: 0 18px; font-size: 14px; }
.btn--lg { height: 56px; padding: 0 32px; font-size: 16px; }
a:focus-visible { outline: 2px solid var(--accent-ink); outline-offset: 3px; }

/* Nav */
.nav {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.nav__inner { display: flex; align-items: center; gap: 36px; height: 72px; }
.nav__links { display: flex; gap: 32px; margin-left: auto; font-size: 15px; color: var(--muted); }
.nav__links a:hover { color: var(--accent-ink); }
.brand { display: inline-flex; align-items: center; color: var(--text); --logo-sign: var(--accent); }
.brand svg { display: block; height: 26px; width: auto; }
.brand--sm svg { height: 20px; }

/* Hero */
.hero { padding-top: clamp(80px, 12vw, 160px); }
.hero__title { font-size: clamp(48px, 8.4vw, 124px); letter-spacing: -0.035em; line-height: 0.98; max-width: 12ch; }
.hero__foot {
  display: flex; justify-content: space-between; align-items: end; gap: 32px 48px; flex-wrap: wrap;
  margin-top: clamp(40px, 5vw, 64px);
}

/* Sections */
.section { padding-top: var(--section); }
.section--band { margin-top: var(--section); padding-bottom: var(--section); }

/* Dark band: a scoped set of neutrals. Derived tokens are restated here so they resolve
   against this band's background, not the page's. */
.on-dark {
  --bg: var(--code-bg);
  --text: var(--light);
  --paper: color-mix(in srgb, var(--light) 9%, var(--bg));
  --shade: #000;
  --surface: color-mix(in srgb, var(--text) 6%, var(--bg));
  --sub: var(--surface);
  --sub-2: color-mix(in srgb, var(--text) 10%, var(--bg));
  --base: color-mix(in srgb, var(--text) 4%, var(--bg));
  --line: color-mix(in srgb, var(--text) 14%, var(--bg));
  --mid: color-mix(in srgb, var(--text) 24%, var(--bg));
  --faint: color-mix(in srgb, var(--text) 48%, var(--bg));
  --muted: color-mix(in srgb, var(--text) 70%, var(--bg));
  --ink-2: color-mix(in srgb, var(--text) 82%, var(--bg));
  --accent-ink: var(--code-key);
  background: var(--bg); color: var(--text);
}
.head { display: grid; grid-template-columns: 1fr 2fr; gap: 24px 48px; align-items: baseline; margin-bottom: clamp(48px, 6vw, 80px); }
.head .eyebrow { margin: 0; }

/* Services */
.services {
  list-style: none; margin: 0; padding: 0;
  display: grid; grid-template-columns: 1fr 1fr;
  border-top: 1px solid var(--line);
}
.services li {
  display: grid; grid-template-columns: 48px 1fr; column-gap: 16px; row-gap: 10px;
  padding: 36px 40px 40px 0; border-bottom: 1px solid var(--line);
}
.services li:nth-child(odd) { border-right: 1px solid var(--line); }
.services li:nth-child(even) { padding-left: 40px; padding-right: 0; }
.services .num { grid-row: span 2; padding-top: 3px; }
.services p { color: var(--muted); font-size: 16px; max-width: 44ch; }

/* Steps */
.steps { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.steps li { padding: 32px 28px 36px; background: var(--surface); border-radius: 6px; display: grid; gap: 12px; align-content: start; }
.steps h3 { display: flex; align-items: baseline; gap: 12px; font-size: 26px; font-weight: 600; letter-spacing: -0.03em; }
.steps h3 .num { font-size: 16px; }
.steps p { color: var(--muted); font-size: 16px; }

/* Statement */
.statement {
  font-size: clamp(28px, 3.6vw, 46px); font-weight: 500; line-height: 1.2; letter-spacing: -0.03em;
  max-width: 26ch;
}

/* Contact */
.contact { margin-top: var(--section); padding: var(--section) 0; background: var(--band); color: var(--band-fg); }
.contact__inner { display: flex; justify-content: space-between; align-items: end; gap: 32px; flex-wrap: wrap; }
.contact h2 { font-size: clamp(40px, 6vw, 84px); max-width: 14ch; }
.contact em { color: inherit; }
.contact .btn { background: var(--band-fg); color: var(--band); }
.contact .btn:hover { background: var(--accent); color: var(--on-accent); }
html[data-band="accent"] .contact .btn:hover { background: color-mix(in srgb, var(--band-fg) 80%, var(--band)); color: var(--band); }

/* Footer */
.footer { background: var(--foot-bg); color: color-mix(in srgb, var(--light) 55%, var(--foot-bg)); border-top: 1px solid color-mix(in srgb, var(--light) 12%, var(--foot-bg)); padding: 28px 0; font-size: 13px; }
.footer__link { color: inherit; text-decoration: underline; text-underline-offset: 3px; }
.footer__link:hover { color: var(--light, var(--text)); }
.footer__inner { display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; }
.footer .brand { color: var(--light); --logo-sign: color-mix(in srgb, var(--accent) 45%, #fff); }

/* Responsive */
@media (max-width: 900px) {
  .head { grid-template-columns: 1fr; }
  .services { grid-template-columns: 1fr; }
  .services li, .services li:nth-child(odd), .services li:nth-child(even) { padding: 32px 0; border-right: 0; }
  .steps { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  body { font-size: 16px; }
  .nav__links { display: none; }
  .nav__inner { justify-content: space-between; }
  .services li { grid-template-columns: 36px 1fr; }
}