/* Polymath Industrial — Base styles
 * Reset, typography, layout primitives, header & footer chrome.
 */

/* ── Reset ────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html, body { height: 100%; }
body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: var(--leading-body);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

img, svg, video { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
input, textarea, select { font: inherit; color: inherit; }
a { color: var(--fg); text-decoration: none; }

/* Tasteful focus ring */
:focus-visible {
  outline: 2px solid var(--rust);
  outline-offset: 3px;
  border-radius: 2px;
}

/* ── Background atmosphere ────────────────────────────────────────── */
body {
  background:
    radial-gradient(ellipse 80% 50% at 50% -10%,
      rgba(184, 84, 42, 0.08), transparent 70%),
    radial-gradient(ellipse 60% 40% at 0% 100%,
      rgba(74, 107, 74, 0.06), transparent 70%),
    var(--ground-0);
  background-attachment: fixed;
  position: relative;
}

/* Subtle film grain */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  opacity: 0.035;
  mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='200' height='200'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/></filter><rect width='100%25' height='100%25' filter='url(%23n)' opacity='1'/></svg>");
}

/* ── Layout primitives ────────────────────────────────────────────── */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding-left:  var(--container-pad);
  padding-right: var(--container-pad);
}

/* Section structure with eyebrow numbering */
.section { padding: var(--s-9) 0; position: relative; }
.section + .section { border-top: 1px solid var(--border); }

.section-eyebrow {
  display: flex;
  align-items: center;
  gap: var(--s-3);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  color: var(--bone-2);
  margin-bottom: var(--s-5);
}
.section-eyebrow::before {
  content: "";
  display: block;
  width: 32px;
  height: 1px;
  background: var(--rust);
}

.section-title {
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: clamp(var(--fs-2xl), 4vw, var(--fs-3xl));
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
  margin-bottom: var(--s-5);
  max-width: 24ch;
}

.section-lede {
  font-size: var(--fs-md);
  color: var(--fg-dim);
  line-height: var(--leading-body);
  max-width: 60ch;
  margin-bottom: var(--s-7);
}

/* ── Header ───────────────────────────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(14, 16, 18, 0.85);
  backdrop-filter: blur(12px) saturate(140%);
  -webkit-backdrop-filter: blur(12px) saturate(140%);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--s-4);
  padding-bottom: var(--s-4);
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--s-3);
  color: var(--bone-0);
  transition: color var(--dur-fast) var(--ease-out);
}
.brand:hover { color: var(--rust-bright); }
.brand-mark { color: var(--rust); flex-shrink: 0; }
.brand-text { display: flex; flex-direction: column; line-height: 1; }
.brand-name {
  font-weight: 700;
  font-size: var(--fs-md);
  letter-spacing: var(--tracking-tight);
}
.brand-sub {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--bone-2);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  margin-top: 2px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--s-6);
}
.site-nav a {
  font-size: var(--fs-sm);
  color: var(--fg-dim);
  position: relative;
  padding: var(--s-2) 0;
  transition: color var(--dur-fast) var(--ease-out);
}
.site-nav a:hover { color: var(--bone-0); }
.site-nav a::after {
  content: "";
  position: absolute;
  bottom: 0; left: 0;
  width: 0; height: 1px;
  background: var(--rust);
  transition: width var(--dur-base) var(--ease-out);
}
.site-nav a:hover::after { width: 100%; }

.nav-cta {
  padding: var(--s-2) var(--s-4) !important;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-md);
  color: var(--bone-0) !important;
}
.nav-cta:hover {
  border-color: var(--rust);
  background: rgba(184, 84, 42, 0.08);
}
.nav-cta::after { display: none; }

.nav-toggle {
  display: none;
  width: 40px; height: 40px;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--bone-0);
  transition: transform var(--dur-fast) var(--ease-out),
              opacity var(--dur-fast) var(--ease-out);
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

@media (max-width: 820px) {
  .site-nav {
    position: fixed;
    top: 65px; left: 0; right: 0;
    background: var(--ground-1);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    align-items: stretch;
    padding: var(--s-5) var(--container-pad);
    gap: var(--s-4);
    transform: translateY(-110%);
    transition: transform var(--dur-base) var(--ease-out);
  }
  .site-nav.open { transform: translateY(0); }
  .nav-toggle { display: flex; }
}

/* ── Footer ───────────────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--ground-1);
  padding: var(--s-7) 0;
  margin-top: var(--s-9);
  position: relative;
  z-index: 2;
}
.footer-inner {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: var(--s-6);
  align-items: center;
}
.footer-brand { display: flex; flex-direction: column; gap: var(--s-1); }
.footer-name { font-weight: 600; color: var(--bone-0); }
.footer-loc { font-family: var(--font-mono); font-size: var(--fs-xs); color: var(--bone-2); }
.footer-contact { text-align: center; }
.footer-contact a {
  color: var(--rust-bright);
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  transition: color var(--dur-fast) var(--ease-out);
}
.footer-contact a:hover { color: var(--bone-warm); }
.footer-meta {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: var(--s-1);
  font-size: var(--fs-xs);
  color: var(--bone-2);
}
.footer-meta .mono { font-family: var(--font-mono); color: var(--bone-3); }

@media (max-width: 720px) {
  .footer-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .footer-meta { align-items: center; }
}

/* ── Buttons ──────────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--s-3);
  padding: var(--s-4) var(--s-6);
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: var(--fs-sm);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  transition: all var(--dur-base) var(--ease-out);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}
.btn-primary {
  background: var(--rust);
  color: var(--bone-0);
  border-color: var(--rust);
}
.btn-primary:hover {
  background: var(--rust-bright);
  border-color: var(--rust-bright);
  transform: translateY(-1px);
  box-shadow: 0 8px 24px rgba(184, 84, 42, 0.3);
}
.btn-secondary {
  background: transparent;
  color: var(--bone-0);
  border-color: var(--border-soft);
}
.btn-secondary:hover {
  border-color: var(--bone-0);
  background: rgba(244, 237, 224, 0.04);
}
.btn .arr {
  display: inline-block;
  transition: transform var(--dur-base) var(--ease-out);
}
.btn:hover .arr { transform: translateX(4px); }

/* ── Mono code/data tags ──────────────────────────────────────────── */
.mono { font-family: var(--font-mono); }
.kicker {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  color: var(--rust);
  padding: var(--s-1) var(--s-3);
  border: 1px solid var(--rust-deep);
  border-radius: 2px;
}