/* ============================================================
   /css/core.css — Phase 2B-1 PLACEHOLDER stylesheet.

   This is infrastructure, not design: it exists so the head's
   filemtime() cache-busting can be exercised, and so structural
   accessibility (skip link, focus visibility) works during
   foundation testing. The real design system, tokens, and
   typography arrive in Phase 3 and will replace this file's
   contents entirely (architecture §12).
   ============================================================ */

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, sans-serif;
  line-height: 1.6;
  color: #1a1a1a;
  background: #ffffff;
}

/* Skip link: visually hidden until keyboard focus (structural a11y). */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: #0e1c36;
  color: #ffffff;
  padding: 8px 14px;
  text-decoration: none;
}
.skip-link:focus { left: 0; }

:focus-visible { outline: 3px solid #0e1c36; outline-offset: 2px; }

.site-header, .site-footer {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid #d0d0d0;
}
.site-footer { border-bottom: 0; border-top: 1px solid #d0d0d0; margin-top: 2rem; }

.site-header nav ul, .site-footer nav ul {
  list-style: none;
  margin: 0.25rem 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

main { max-width: 46rem; margin: 0 auto; padding: 1.5rem 1rem 3rem; }