/* AI Foundation — cost-accounting workzone visuals.
   The business logic of how AI spend is counted, top-down:
   · ca-hero — the mental model: AI calls → accounting (aggregate + journals)
     → the AI spend screen. Nodes/edges mirror tc-hero so the two read alike.
   · ca-map — the connective table: each screen view × its source × unit × scope.
   · ca-vs — two-up cards for the one decision: why two sources (model_usage
     aggregate vs per-person journals), mirroring tc-vs.
   · ca-scope — the v1/v2 boundary as two stacked rails.
   Reuses module.css + layered-stack.css primitives (the stk-dec__list
   decision-list in #periods); adds only the page-bespoke pieces above.
   Loaded by _workzone/cost-accounting.html on top of those two sheets.
   Placement convention: docs/architecture/README.md §Styling. */

/* ════════ MENTAL MODEL ════════ */

/* Concept poster: where counting sits — every AI call is metered into the
   registry (full platform spend) and, for chat/agents, into the journals
   (per-person attribution); the screen reads both. Same visual language as
   tool-catalog's tc-hero. */
.ca-hero {
  background: var(--tint-6);
  border: 1.5px solid var(--accent-muted);
  border-radius: var(--radius-md);
  padding: 1rem 1rem 0.85rem;
  margin: 0 0 2rem;
}

.ca-flow {
  display: flex;
  align-items: stretch;
  justify-content: center;
  gap: 0.4rem;
  flex-wrap: wrap;
}

.ca-node {
  flex: 0 1 14rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  text-align: center;
  padding: 0.7rem 0.75rem;
  border-radius: var(--radius-md);
  background: var(--surface);
  border: 1.5px solid var(--border);
}
.ca-node--calls {
  border-color: var(--accent);
}
.ca-node--store {
  border-color: var(--s2);
}
.ca-node--screen {
  border-color: var(--s3);
}
.ca-node__g {
  font-size: 1.15rem;
  line-height: 1;
}
.ca-node__t {
  font-weight: 700;
  font-size: 0.84rem;
  color: var(--text);
}
.ca-node__s {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--text-dim);
  line-height: 1.45;
}

.ca-edge {
  flex: 0 1 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-width: 5.5rem;
  gap: 0.1rem;
}
.ca-edge__arr {
  color: var(--accent);
  font-weight: 700;
  font-family: var(--mono);
}
.ca-edge__lbl {
  font-size: 0.66rem;
  color: var(--text-dim);
  text-align: center;
  line-height: 1.25;
}

/* Footer line: the two roles of the two write-paths. */
.ca-hero__foot {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.4rem 1.1rem;
  margin-top: 0.85rem;
  padding-top: 0.7rem;
  border-top: 1px dashed var(--border);
  font-size: 0.78rem;
  color: var(--text-dim);
}
.ca-hero__foot b {
  color: var(--text);
  font-weight: 700;
}

/* ════════ CONNECTIVE MAP ════════ */

/* The four screen views as a table: where each reads from, in what unit, over
   what scope. This is the page's spine — the screen renders it, here it's the
   data lineage. */
.ca-map {
  width: 100%;
  border-collapse: collapse;
  margin: 0.3rem 0 0;
  font-size: 0.82rem;
}
.ca-map th,
.ca-map td {
  text-align: left;
  padding: 0.5rem 0.7rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
.ca-map thead th {
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
  font-weight: 700;
  border-bottom: 1.5px solid var(--border);
}
.ca-map tbody td:first-child {
  font-weight: 700;
  color: var(--text);
  white-space: nowrap;
}
.ca-map td code {
  font-size: 0.92em;
}
.ca-map__src {
  color: var(--text-dim);
}

/* ════════ TWO SOURCES ════════ */

/* Side-by-side cards for the one fork the feature turns on: a full-spend
   aggregate vs per-person journals. Coloured top edge per column, same idiom
   as tc-vs. */
.ca-vs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.7rem;
  margin: 0.3rem 0 0;
}
.ca-vs__col {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  background: var(--paper);
  border: 1px solid var(--border);
  border-top: 3px solid var(--text-muted);
  border-radius: var(--radius-md);
  padding: 0.75rem 0.85rem;
}
.ca-vs__col--agg {
  border-top-color: var(--s2);
}
.ca-vs__col--journal {
  border-top-color: var(--accent);
}
.ca-vs__head {
  display: flex;
  align-items: baseline;
  gap: 0.45rem;
}
.ca-vs__name {
  font-weight: 700;
  font-size: 0.92rem;
  color: var(--text);
  font-family: var(--mono);
}
.ca-vs__kind {
  font-size: 0.62rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
}
.ca-vs__lines {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  margin: 0;
  padding: 0;
}
.ca-vs__line {
  font-size: 0.82rem;
  color: var(--text-dim);
  line-height: 1.4;
  padding-left: 0.85rem;
  position: relative;
}
.ca-vs__line::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.5em;
  width: 0.32rem;
  height: 0.32rem;
  border-radius: 50%;
  background: var(--accent-muted);
}
.ca-vs__take {
  margin-top: 0.7rem;
  font-size: 0.82rem;
  color: var(--text-dim);
  line-height: 1.5;
}
.ca-vs__take b {
  color: var(--text);
  font-weight: 700;
}

/* ════════ V1 / V2 SCOPE ════════ */

/* Two stacked rails — what counts in v1, what defers to v2. Green rail in,
   muted dashed rail later; same palette idiom as the iter labels. */
.ca-scope {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin: 0.3rem 0 0;
}
.ca-rail {
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  padding: 0.6rem 0.8rem;
  border-radius: var(--radius-md);
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--s3);
}
.ca-rail--v2 {
  border-left-color: var(--text-muted);
  border-style: dashed;
}
.ca-rail__tag {
  flex: none;
  font-family: var(--mono);
  font-size: 0.7rem;
  font-weight: 700;
}
.ca-rail__tag--v1 {
  color: var(--s3);
}
.ca-rail__tag--v2 {
  color: var(--text-muted);
}
.ca-rail__body {
  font-size: 0.82rem;
  color: var(--text-dim);
  line-height: 1.5;
}
.ca-rail__body b {
  color: var(--text);
  font-weight: 700;
}

/* ════════ RESPONSIVE ════════ */

@media (max-width: 640px) {
  .ca-vs {
    grid-template-columns: 1fr;
  }
}