/* Query Engine — data-model workzone diagram (dm-*).
   Same trimmed subset as email/_workzone/data-model.css: the shared stk-*
   layered-stack bands carry one DB-table sub-block per table (field · type ·
   constraint chips · note) plus .stk-dec design notes, and a producer/consumer
   boundary block (dm-border) at the foot. Query Engine owns dialogue + the
   access signal — it stores no knowledge, only references KS entity ids — so the
   tables are conversations · messages · retrieval_trace · access_counter, and
   the boundary leans toward Knowledge Store rather than away from a producer.
   Static — no hover affordance (README §Hover).
   Loaded by _workzone/data-model.html on top of ../../module.css
   + ../../layered-stack.css.
   Placement convention: docs/architecture/README.md §Styling. */

/* ── Layer accent presets ── */
.stk-layer--qe {
  --stk-lc: var(--accent);
  --stk-lc-pale: var(--tint-8);
}
.stk-layer--signal {
  --stk-lc: var(--s3-glow);
  --stk-lc-pale: var(--s3-pale);
}

/* ── Constraint chips ── */
.dm-c {
  display: inline-flex;
  align-items: center;
  font-family: var(--mono);
  font-size: 0.6rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  padding: 0.12rem 0.4rem;
  border-radius: var(--pill-radius);
  line-height: 1.4;
  white-space: nowrap;
}
.dm-c--pk {
  background: var(--s1);
  color: #fff;
}
.dm-c--fk {
  background: var(--s2);
  color: #fff;
}
.dm-c--nn {
  background: var(--s3);
  color: #fff;
}
.dm-c--idx {
  background: var(--s4);
  color: #fff;
}
.dm-c--null {
  background: var(--paper);
  color: var(--text-muted);
  border: 1px solid var(--accent-muted);
}
.dm-c--chk {
  background: var(--tint-15);
  color: var(--accent);
  border: 1px solid var(--tint-25);
}
.dm-c--def {
  background: var(--s2-pale);
  color: var(--s2);
  border: 1px solid var(--tint-15);
}
.dm-c--ref {
  background: var(--tint-15);
  color: var(--accent);
  border: 1px solid var(--tint-25);
}

/* ── DB-table sub-block (lives inside a .stk-layer__body) ── */
.dm-tbl {
  flex: 1 1 100%;
  min-width: 280px;
  align-self: stretch;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  overflow: hidden;
}
.dm-tbl__head {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  padding: 0.5rem 0.75rem;
  background: var(--tint-6);
  border-bottom: 1px solid var(--border);
}
.dm-tbl__name {
  font-family: var(--mono);
  font-size: 0.86rem;
  font-weight: 700;
  color: var(--text);
}
.dm-tbl__sub {
  font-size: 0.66rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.dm-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin-left: auto;
}
.dm-badge {
  font-family: var(--mono);
  font-size: 0.58rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  padding: 0.16rem 0.4rem;
  border-radius: var(--tag-radius);
  border: 1px solid var(--tint-25);
  color: var(--text-dim);
  background: var(--tint-6);
  white-space: nowrap;
}
.dm-badge--fk {
  color: var(--s2);
  border-color: rgba(136, 96, 64, 0.4);
  background: rgba(136, 96, 64, 0.08);
}
.dm-badge--fk::before {
  content: "⛓ ";
}
.dm-badge--uniq {
  color: var(--s3);
  border-color: rgba(106, 128, 72, 0.4);
  background: var(--s3-pale);
}
.dm-badge--flag {
  color: var(--s4);
  border-color: rgba(160, 88, 56, 0.35);
  background: var(--s4-pale);
}

/* ── Matrix-style field rows: field · type · constraint chips · note ── */
.dm-fields {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
}
.dm-fields td {
  padding: 0.32rem 0.75rem;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--border);
}
.dm-fields tr:last-child td {
  border-bottom: none;
}
.dm-fields .dm-f {
  font-family: var(--mono);
  font-size: 0.76rem;
  font-weight: 700;
  color: var(--text);
  white-space: nowrap;
}
.dm-fields .dm-t {
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--text-dim);
  white-space: nowrap;
}
.dm-fields .dm-cons {
  white-space: nowrap;
}
.dm-fields .dm-cons .dm-c {
  margin: 1px 2px 1px 0;
}
.dm-fields .dm-note {
  font-size: 0.74rem;
  color: var(--text-dim);
  line-height: 1.4;
}
.dm-fields tr.is-pk td:first-child {
  box-shadow: inset 3px 0 0 var(--s1);
}
.dm-fields tr.is-fk td:first-child {
  box-shadow: inset 3px 0 0 var(--s2);
}

/* ════════════════ REFERENCES-NOT-COPIES BOUNDARY ════════════════ Query
   Engine stores dialogue + the access signal; the entity ids it holds in
   retrieval_trace / access_counter are references into Knowledge Store, not
   copies of knowledge. Two-column block: what QE keeps · what stays in KS. */
.dm-border {
  display: flex;
  gap: 0.75rem;
  margin: 0.9rem 0 0.3rem;
}
.dm-border__col {
  flex: 1;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 0.85rem 1rem;
}
.dm-border__col--here {
  border-left: 4px solid var(--accent);
  background: var(--tint-6);
}
.dm-border__col--there {
  border-left: 4px solid var(--s2);
}
.dm-border__head {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  margin-bottom: 0.45rem;
}
.dm-border__who {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text);
}
.dm-border__act {
  font-family: var(--mono);
  font-size: 0.6rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}
.dm-border__col--here .dm-border__act {
  color: var(--accent);
}
.dm-border__d {
  font-size: 0.78rem;
  color: var(--text-dim);
  line-height: 1.55;
}
.dm-border__seam {
  align-self: center;
  font-size: 1rem;
  color: var(--accent);
}

@media (max-width: 640px) {
  .dm-border {
    flex-direction: column;
  }
}