/* ==========================================================================
   catalog.css — the searchable/filterable tree catalogue at /trees/.

   Design system: aiskilltrees-style v1.0. Loads after tokens.css, base.css
   and components.css. No hardcoded hex values, no font stacks.

   The layout is a two-column faceted search: a sticky filter rail on the
   left, results on the right. Below 900px the rail becomes a disclosure
   panel above the results — see the note at the bottom of this file.
   ========================================================================== */

/* Two tighter band rhythms, for the control strip and the results band. The
   default --space-band is tuned for a marketing page; a tool page with a
   search field and a result grid reads as one unit and needs less air between
   its parts. Kept here rather than in base.css because nothing else on the
   site needs them yet. */
.band--snug  { padding-block: var(--space-5); }

/* --------------------------------------------------------------------------
   Search bar. Sits in its own --paper-2 band directly under the page header,
   so it reads as one control strip across the full width.
   -------------------------------------------------------------------------- */

.searchbar { display: flex; flex-wrap: wrap; gap: var(--space-2); align-items: flex-end; }

.searchbar__field { flex: 1 1 22rem; min-width: 0; }
.searchbar__field--narrow { flex: 0 1 14rem; }

.field-label {
  display: block;
  font-size: var(--step-xs);
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin-bottom: var(--space-1);
}

.input, .select {
  width: 100%;
  font-family: var(--font-sans);
  font-size: var(--step-s);
  line-height: 1.4;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--rule-strong);
  border-radius: 0;                      /* square — the system has no rounded containers */
  padding: 0.7rem 0.9rem;
  min-height: 44px;                      /* tap target */
  transition: border-color 150ms ease;
}
.input:hover, .select:hover { border-color: var(--ink-2); }
.input::placeholder { color: var(--ink-3); }

/* The native select arrow is drawn with a rotated square border rather than
   an inline SVG, so the chevron stays a token color instead of a hardcoded
   fill baked into a data: URI. */
.select { appearance: none; padding-right: 2.2rem; }
.select-wrap { position: relative; }
.select-wrap::after {
  content: "";
  position: absolute;
  right: 1rem;
  top: 50%;
  width: 0.45rem;
  height: 0.45rem;
  border-right: 2px solid var(--ink-2);
  border-bottom: 2px solid var(--ink-2);
  transform: translateY(-70%) rotate(45deg);
  pointer-events: none;
}

/* --------------------------------------------------------------------------
   The two-column shell.
   -------------------------------------------------------------------------- */

.catalog {
  display: grid;
  grid-template-columns: minmax(0, 16rem) minmax(0, 1fr);
  gap: var(--space-5);
  align-items: start;
}

/* --------------------------------------------------------------------------
   Filter rail.
   -------------------------------------------------------------------------- */

.filters { position: sticky; top: var(--space-2); }

.filters__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2);
  padding-bottom: var(--space-2);
  border-bottom: 1px solid var(--rule);
  margin-bottom: var(--space-3);
}
.filters__head h2 { font-size: var(--step-l); margin: 0; }

.facet { border: 0; padding: 0; margin: 0 0 var(--space-4); }

.facet__legend {
  font-size: var(--step-s);
  font-weight: 600;
  color: var(--ink);
  padding: 0;
  margin-bottom: var(--space-1);
}

.facet__list { list-style: none; margin: 0; padding: 0; }

.facet__row {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.35rem 0;
  min-height: 34px;
  cursor: pointer;
  font-size: var(--step-s);
  color: var(--ink-2);
}
.facet__row:hover { color: var(--ink); }

.facet__row input {
  appearance: none;
  flex: none;
  width: 18px;
  height: 18px;
  border: 1px solid var(--rule-strong);
  background: var(--surface);
  border-radius: 0;
  display: grid;
  place-content: center;
  cursor: pointer;
  transition: background 150ms ease, border-color 150ms ease;
}
.facet__row input::after {
  content: "";
  width: 10px;
  height: 6px;
  border-left: 2px solid var(--ink-inverse);
  border-bottom: 2px solid var(--ink-inverse);
  transform: rotate(-45deg) translate(1px, -1px);
  opacity: 0;
}
.facet__row input:checked { background: var(--primary); border-color: var(--primary); }
.facet__row input:checked::after { opacity: 1; }
.facet__row input:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; }

.facet__name { flex: 1 1 auto; }

.facet__count {
  flex: none;
  font-size: var(--step-xs);
  color: var(--ink-3);
  font-variant-numeric: tabular-nums;
}

/* A value that nothing in the current result set has. Kept visible rather
   than removed, so the rail does not jump around as filters change — but
   disabled, and told apart by more than color: the label dims AND the count
   reads 0. */
.facet__row.is-empty { color: var(--ink-3); cursor: not-allowed; opacity: 0.55; }
.facet__row.is-empty input { cursor: not-allowed; }

/* --------------------------------------------------------------------------
   Results.
   -------------------------------------------------------------------------- */

.results__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2);
  padding-bottom: var(--space-2);
  border-bottom: 1px solid var(--rule);
  margin-bottom: var(--space-3);
}

.results__count { font-size: var(--step-s); color: var(--ink-2); margin: 0; }
.results__count strong { color: var(--ink); font-variant-numeric: tabular-nums; }

/* Active-filter chips: a removable summary of what is currently applied, so
   the state is legible without scanning the rail. */
.chips { display: flex; flex-wrap: wrap; gap: var(--space-1); margin-bottom: var(--space-3); }
.chips:empty { display: none; }

.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-sans);
  font-size: var(--step-xs);
  color: var(--ink);
  background: var(--primary-tint);
  border: 1px solid color-mix(in srgb, var(--primary) 35%, transparent);
  border-radius: 0;
  padding: 0.35rem 0.6rem;
  min-height: 32px;
  cursor: pointer;
  transition: background 150ms ease;
}
.chip:hover { background: color-mix(in srgb, var(--primary) 18%, var(--paper)); }
.chip__x { font-size: var(--step-s); line-height: 1; color: var(--ink-2); }

.linkbtn {
  font-family: var(--font-sans);
  font-size: var(--step-xs);
  color: var(--primary);
  background: none;
  border: 0;
  padding: 0.35rem 0;
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 0.15em;
}
.linkbtn:hover { color: var(--primary-strong); }
.linkbtn[hidden] { display: none; }

.treegrid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 20rem), 1fr));
  gap: var(--space-2);
  list-style: none;
  margin: 0;
  padding: 0;
}

/* The card. --surface fill, square, 1px rule, no shadow — the system's card. */
.treecard {
  display: flex;
  flex-direction: column;
  height: 100%;
  background: var(--surface);
  border: 1px solid var(--rule);
  padding: var(--space-3);
  color: var(--ink);
  text-decoration: none;
  transition: border-color 150ms ease, background 150ms ease;
}
.treecard:hover { border-color: var(--primary); background: var(--primary-tint); color: var(--ink); }

.treecard__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 0.75rem;
  font-size: var(--step-xs);
  color: var(--ink-3);
  margin-bottom: var(--space-1);
}

.treecard__title { font-size: var(--step-l); margin: 0 0 0.25rem; }
.treecard__subtitle { font-size: var(--step-xs); color: var(--ink-2); margin: 0 0 var(--space-2); }

.treecard__summary {
  font-family: var(--font-serif);
  font-size: var(--step-s);
  line-height: 1.55;
  color: var(--ink-2);
  margin: 0 0 var(--space-3);
}

.treecard__foot {
  margin-top: auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-1);
  padding-top: var(--space-2);
  border-top: 1px solid var(--rule);
  font-size: var(--step-xs);
  color: var(--ink-3);
}
.treecard__go { color: var(--primary); font-weight: 500; }
.treecard:hover .treecard__go { color: var(--primary-strong); }

.empty {
  border: 1px dashed var(--rule-strong);
  padding: var(--space-5) var(--space-3);
  text-align: center;
  color: var(--ink-2);
}
.empty h3 { margin-bottom: var(--space-1); }

.loading { color: var(--ink-3); font-size: var(--step-s); }

/* --------------------------------------------------------------------------
   Responsive. The system's breakpoints are 768 and 1024; this file adds 900,
   where the 16rem rail genuinely stops fitting beside a 20rem card grid.
   Below it the rail becomes a disclosure panel: catalog.js flips
   .filters[data-collapsed], and the toggle button only exists here.
   -------------------------------------------------------------------------- */

.filters__toggle { display: none; }

@media (max-width: 900px) {
  .catalog { grid-template-columns: 1fr; gap: var(--space-3); }
  .filters { position: static; }

  .filters__toggle {
    display: inline-flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-2);
    width: 100%;
    min-height: 44px;
    font-family: var(--font-sans);
    font-size: var(--step-s);
    font-weight: 500;
    color: var(--ink);
    background: var(--surface);
    border: 1px solid var(--rule-strong);
    border-radius: 0;
    padding: 0.7rem 0.9rem;
    cursor: pointer;
  }

  .filters__head { display: none; }
  .filters[data-collapsed="true"] .filters__body { display: none; }
  .filters__body { padding-top: var(--space-3); }
}