/* ── Design Tokens ─────────────────────────────────────────── */
:root {
  --bg: #FFFFFF;
  --fg: #000000;
  --muted: #F5F5F5;
  --muted-fg: #525252;
  --border: #000000;
  --border-light: #E5E5E5;
  --font-display: "Playfair Display", Georgia, serif;
  --font-body: "Source Serif 4", Georgia, serif;
  --font-mono: "JetBrains Mono", monospace;
}

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

html {
  font-size: 16px;
}

body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-body);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
  text-decoration: none;
}

/* ── Global noise texture (paper quality) ───────────────────── */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
  opacity: 0.02;
  pointer-events: none;
  z-index: 9999;
}

/* ── Skip link (accessibility) ──────────────────────────────── */
.skip-link {
  position: absolute;
  left: 0;
  top: -60px;
  background: var(--fg);
  color: var(--bg);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  padding: 0.75rem 1.5rem;
  z-index: 10000;
  transition: top 100ms;
}
.skip-link:focus {
  top: 0;
}

/* ── Navigation ─────────────────────────────────────────────── */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem 3rem;
  border-bottom: 1px solid var(--border);
}

.nav-logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.025em;
}

.nav-links {
  display: flex;
  gap: 2.5rem;
  list-style: none;
}

.nav-links a {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  transition: border-color 100ms;
}

.nav-links a:hover,
.nav-links a:focus-visible {
  border-bottom-color: var(--border);
  outline: none;
}

.nav-links a[aria-current="page"] {
  border-bottom-color: var(--border);
}

/* ── Section divider ────────────────────────────────────────── */
hr {
  border: none;
  border-top: 4px solid var(--fg);
}

hr.light {
  border-top: 1px solid var(--border-light);
}

/* ── Buttons ────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--fg);
  color: var(--bg);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 1rem 2rem;
  border: 2px solid var(--fg);
  white-space: nowrap;
  transition: background 100ms, color 100ms;
  cursor: pointer;
}

.btn:hover {
  background: var(--bg);
  color: var(--fg);
}

.btn:focus-visible {
  outline: 3px solid var(--fg);
  outline-offset: 3px;
}

/* ── Footer ─────────────────────────────────────────────────── */
footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 2rem 3rem;
  border-top: 1px solid var(--border-light);
}

.footer-copy {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--muted-fg);
  letter-spacing: 0.05em;
}

.footer-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.footer-links a {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted-fg);
  border-bottom: 1px solid transparent;
  transition: color 100ms, border-color 100ms;
}

.footer-links a:hover {
  color: var(--fg);
  border-bottom-color: var(--fg);
}

/* ── Responsive base ────────────────────────────────────────── */
@media (max-width: 768px) {
  nav {
    padding: 1.25rem 1.5rem;
  }

  .nav-links {
    gap: 1.5rem;
  }

  footer {
    flex-direction: column;
    gap: 1rem;
    align-items: flex-start;
    padding: 1.5rem;
  }
}