/* ============================================================
   Polytech Instruments — Design tokens, reset, typography
   ============================================================ */

:root {
  /* ---- Color ----
     Navy and accent are derived from the real Polytech logo (sampled from
     images/site/logo.png: brand blue ~#1a5ea3) — not an invented palette. */
  --color-ink: #141a22;
  --color-navy: #0d2540;
  --color-navy-mid: #163a63;
  --color-paper: #faf9f6;
  --color-surface: #ffffff;
  --color-accent: #1a5ea3;
  --color-accent-dark: #134876;

  --color-gray-100: #f4f4f2;
  --color-gray-200: #e6e5e1;
  --color-gray-300: #cfcdc6;
  --color-gray-500: #8a8d93;
  --color-gray-700: #565a62;
  --color-gray-900: #3a3d44;

  --color-text: var(--color-ink);
  --color-text-muted: var(--color-gray-700);
  --color-text-inverse: #f4f4f2;
  --color-border: var(--color-gray-200);

  /* ---- Type ----
     Public Sans carries body copy and UI chrome; Space Grotesk is reserved
     for headings and the wordmark — that pairing (not a monospace font
     scattered through labels) is what gives this its designed feel. */
  --font-sans: 'Public Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Arial, sans-serif;
  --font-display: 'Space Grotesk', var(--font-sans);

  --fs-h1: clamp(2rem, 1.5rem + 2.2vw, 3rem);
  --fs-h2: clamp(1.5rem, 1.25rem + 1.2vw, 2.125rem);
  --fs-h3: clamp(1.25rem, 1.1rem + 0.6vw, 1.5rem);
  --fs-body: 1rem;
  --fs-small: 0.875rem;
  --fs-micro: 0.75rem;

  /* ---- Space (4px base) ---- */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;
  --space-8: 64px;
  --space-9: 96px;
  --space-10: 128px;

  /* ---- Layout ---- */
  --content-max: 1280px;
  --radius: 10px;
  --radius-lg: 16px;
  --header-height: 84px;
  --header-height-shrunk: 60px;

  /* ---- Motion ---- */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --dur-fast: 150ms;
  --dur-mid: 250ms;
  --dur-slow: 400ms;

  /* ---- Shadow ---- */
  --shadow-sm: 0 1px 2px rgba(16, 26, 46, 0.06), 0 1px 1px rgba(16, 26, 46, 0.04);
  --shadow-md: 0 12px 28px rgba(16, 26, 46, 0.12);

  /* ---- Tinted section backgrounds (alternated for visual rhythm) ---- */
  --color-tint: #eef4fa;
  --color-tint-border: #dde8f2;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-paper);
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; margin: 0; padding: 0; }
button { font: inherit; cursor: pointer; }
input, select, textarea { font: inherit; }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.15;
  margin: 0;
  color: var(--color-navy);
  letter-spacing: -0.01em;
}
h1 { font-size: var(--fs-h1); font-weight: 700; letter-spacing: -0.02em; }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); }
p { margin: 0; color: var(--color-text-muted); }

.container {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 0 var(--space-5);
}
@media (min-width: 1024px) {
  .container { padding: 0 var(--space-6); }
}

.eyebrow {
  display: block;
  font-size: var(--fs-micro);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-2);
}

.label-sm {
  font-family: var(--font-sans);
  font-size: var(--fs-micro);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.07em;
}

.section {
  padding-block: var(--space-9);
}
.section-tint {
  background: var(--color-tint);
  border-top: 1px solid var(--color-tint-border);
  border-bottom: 1px solid var(--color-tint-border);
}
@media (max-width: 640px) {
  .section { padding-block: var(--space-8); }
}

.section-head {
  max-width: 640px;
  margin-bottom: var(--space-6);
}
.section-head p { margin-top: var(--space-3); font-size: 1.0625rem; }

.visually-hidden {
  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: absolute;
  left: -9999px;
  top: 0;
  background: var(--color-navy);
  color: #fff;
  padding: var(--space-3) var(--space-4);
  z-index: 1000;
}
.skip-link:focus { left: var(--space-4); top: var(--space-4); }