/* ==========================================================================
   ARMATECH — base.css
   Brand system derived from the Armatech identity:
   white field · ink black · signal red #b4050a · engineering hairlines.
   Saira Condensed display / Archivo body / IBM Plex Mono callouts.
   ========================================================================== */

:root {
  /* Palette */
  --white: #ffffff;
  --shade: #f5f6f7;        /* alternate section */
  --line: #e6e8eb;         /* hairlines */
  --line-dark: #cfd3d8;
  --ink: #14161a;          /* headings */
  --body: #4d545d;         /* body text */
  --red: #b4050a;          /* brand signal red */
  --red-dark: #8a0408;
  --red-soft: rgba(180, 5, 10, 0.08);

  /* Type */
  --font-display: "Saira Condensed", "Arial Narrow", sans-serif;
  --font-body: "Archivo", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, monospace;

  /* Scale */
  --step-0: 1rem;
  --step-1: 1.15rem;
  --step-2: 1.5rem;
  --step-3: clamp(1.9rem, 1.4rem + 2vw, 2.9rem);
  --step-4: clamp(2.5rem, 1.6rem + 3.8vw, 4.6rem);

  /* Layout */
  --container: 74rem;
  --gutter: clamp(1.25rem, 4vw, 2.5rem);
  --section-pad: clamp(4.5rem, 9vw, 7.5rem);
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: var(--step-0);
  line-height: 1.65;
  color: var(--body);
  background: var(--white);
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

button { font: inherit; cursor: pointer; }
input, textarea { font: inherit; }

::selection { background: var(--red); color: var(--white); }

/* ---------- Typography ---------- */
h1, h2, h3 {
  font-family: var(--font-display);
  color: var(--ink);
  text-transform: uppercase;
  line-height: 1.03;
  font-weight: 700;
  letter-spacing: 0.01em;
}

h1 { font-size: var(--step-4); }
h2 { font-size: var(--step-3); }
h3 { font-size: var(--step-2); font-weight: 600; }

h1 em, h2 em {
  font-style: normal;
  color: var(--red);
}

p { max-width: 64ch; }

a { color: inherit; }

.mono {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

/* ---------- Kicker + speed-lines (from the logo's diagonal strokes) ---------- */
.kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 700;
  font-size: 0.82rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--red);
  margin-bottom: 1rem;
}

.speedlines {
  display: inline-flex;
  gap: 4px;
}

.speedlines i {
  display: block;
  width: 4px;
  height: 1.1em;
  background: var(--ink);
  transform: skewX(-24deg);
}

.speedlines i:last-child { background: var(--red); }

.section-lede {
  margin-top: 1rem;
  font-size: var(--step-1);
}

/* ---------- Blueprint plus-mark background (echoes the brand deck grid) ---------- */
.grid-bg {
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 56px 56px;
  background-position: center;
}

.grid-bg > .container {
  position: relative;
}

/* ---------- Accessibility ---------- */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--red);
  color: var(--white);
  padding: 0.6rem 1rem;
  z-index: 200;
}

.skip-link:focus { left: 0; }

:focus-visible {
  outline: 2px solid var(--red);
  outline-offset: 3px;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}