/* ────────────────────────────────────────────────────────────────────────
   problem-nav.css — chrome for the DSA problem editorials.

   The eight write-ups under DSA/problems/ are self-contained "island" pages:
   each carries its own palette and layout inline, and none of them is on
   assets/notes.css. What they all *do* share is the token vocabulary
   (--paper, --ink, --ink-soft, --line, --mono, --serif, --accent), so this
   file styles the two pieces of chrome the catalogue needs — a way back up,
   and a way sideways to the next editorial — without touching their design.

   Loaded by DSA/problems/<slug>.html. Print hides both: on paper the page is
   the artefact, and navigation is noise.
   ──────────────────────────────────────────────────────────────────────── */

.fieldnav {
  max-width: 920px;
  margin: 0 auto;
  padding: 20px 24px 0;
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .06em;
}

.fieldnav a {
  color: var(--ink-soft);
  opacity: .78;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: opacity .18s cubic-bezier(.22, .61, .36, 1), color .18s cubic-bezier(.22, .61, .36, 1);
}

.fieldnav a:hover { opacity: 1; color: var(--accent); }
.fieldnav .sep { color: var(--line); }

/* ── the strip that closes every editorial ─────────────────────────────── */

.editorial-foot {
  max-width: 920px;
  margin: 56px auto 0;
  padding: 0 24px;
}

.editorial-foot .ef-rule {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 0 0 20px;
}

.editorial-foot .ef-row {
  display: flex;
  align-items: stretch;
  gap: 12px;
  flex-wrap: wrap;
}

.editorial-foot a {
  flex: 1 1 220px;
  min-width: 0;
  text-decoration: none;
  color: inherit;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 14px 16px;
  background: rgba(255, 255, 255, .45);
  transition: border-color .18s cubic-bezier(.22, .61, .36, 1), transform .18s cubic-bezier(.22, .61, .36, 1);
}

.editorial-foot a:hover { border-color: var(--accent); transform: translateY(-1px); }

.editorial-foot .ef-dir {
  display: block;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--ink-soft);
  opacity: .7;
  margin-bottom: 6px;
}

.editorial-foot .ef-name {
  display: block;
  font-family: var(--serif);
  font-size: 17px;
  line-height: 1.25;
}

.editorial-foot a.ef-next { text-align: right; }
.editorial-foot a.ef-all { flex: 0 1 auto; text-align: center; }

@media (max-width: 640px) {
  .editorial-foot a.ef-next { text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
  .fieldnav a, .editorial-foot a { transition-duration: .01ms; }
}

@media print {
  .fieldnav, .editorial-foot { display: none !important; }
}