/* Answer block: ```chart - measured data, drawn with a fit the app computes.
   Tokens come from blocks.css. The four series colours are chart-local tokens
   a palette may restate as --ab-series-1..4; set 1 is the calc colour, so a
   single set reads like the lab guide's blue "you calculate it" line.
   The order (blue, orange, green, violet) passes the data-viz palette check
   on adjacent pairs in both themes; sets 2-4 also get their own marker shape
   (square, triangle, diamond), so no set is told apart by colour alone. */

.ab-chart {
  --abc-s1: var(--ab-series-1, var(--ab-calc));
  --abc-s2: var(--ab-series-2, #e88a52);
  --abc-s3: var(--ab-series-3, #3fb98c);
  --abc-s4: var(--ab-series-4, #d27fd0);
  --abc-c: var(--abc-s1);
  position: relative;
  min-width: 0;
  margin: 18px 0;
  padding: 16px 18px 14px;
  border: 1px solid var(--ab-hair);
  border-radius: var(--ab-radius);
  background: var(--ab-card);
  color: var(--ab-ink);
  font: 400 14px/1.45 var(--ab-font-ui);
}
/* A printed page (page.js .ab-page-print) is light whatever theme the app is
   in, so it takes the light steps too, and Aluma's own: the holder restates
   Aluma's light role tokens, so a palette's series stop at it as well. */
.ab-page-print .ab-chart,
body[data-theme="light"] .ab-chart {
  --abc-s2: var(--ab-series-2, #c4521c);
  --abc-s3: var(--ab-series-3, #158a63);
  --abc-s4: var(--ab-series-4, #7a5bd6);
}
.ab-page-print .ab-chart {
  --ab-series-1: initial;
  --ab-series-2: initial;
  --ab-series-3: initial;
  --ab-series-4: initial;
}
.ab-chart .abc-s1 { --abc-c: var(--abc-s1); }
.ab-chart .abc-s2 { --abc-c: var(--abc-s2); }
.ab-chart .abc-s3 { --abc-c: var(--abc-s3); }
.ab-chart .abc-s4 { --abc-c: var(--abc-s4); }

.ab-chart .abc-sr {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0 0 0 0); clip-path: inset(50%); white-space: nowrap;
}

/* ── Title, equation and key ─────────────────────────────────────────── */
.ab-chart .abc-head { display: block; margin: 0; padding: 0; }
.ab-chart .abc-title {
  display: block;
  font: 600 15px/1.35 var(--ab-font-ui);
  letter-spacing: -0.005em;
  color: var(--ab-ink);
  text-wrap: balance;
}
.ab-chart .abc-cap {
  display: flex; flex-wrap: wrap; align-items: baseline;
  gap: 4px 16px;
  margin: 6px 0 2px;
}
.ab-chart .abc-cap[hidden] { display: none; }
.ab-chart .abc-eq {
  font-family: var(--ab-font-math);
  font-size: 17px;
  line-height: 1.3;
  color: var(--ab-calc);
  white-space: nowrap;
}
.ab-chart .abc-eq sup { font-size: 0.68em; line-height: 0; }
.ab-chart .abc-var { font-style: italic; padding-right: 0.04em; }
.ab-chart .abc-r2 {
  font: 500 13px/1.3 var(--ab-font-ui);
  color: var(--ab-muted);
}
.ab-chart .abc-r2 { font-variant-numeric: tabular-nums; }
.ab-chart .abc-keys {
  display: inline-flex; flex-wrap: wrap; align-items: center;
  gap: 4px 14px;
  font-size: 12.5px;
  color: var(--ab-muted);
}
.ab-chart .abc-key { display: inline-flex; align-items: center; gap: 6px; }
.ab-chart .abc-key-ico { flex: none; overflow: visible; }
.ab-chart .abc-key-ink .abc-fit { stroke: var(--ab-ink); }

/* ── The plot ─────────────────────────────────────────────────────────── */
/* The SVG is laid out at the box's real width (chart.js measures it), so its
   text is true size. Below 220px it keeps 220 and the box scrolls sideways. */
.ab-chart .abc-plot {
  position: relative;
  margin-top: 8px;
  overflow-x: auto;
  overflow-y: hidden;
  border-radius: var(--ab-radius-sm);
  outline: none;
  -webkit-tap-highlight-color: transparent;
}
.ab-chart .abc-plot:focus-visible { box-shadow: 0 0 0 2px var(--ab-card), 0 0 0 4px var(--ab-calc); }
.ab-chart .abc-svg {
  display: block;
  width: 100%;
  min-width: 220px;
  height: auto;
  overflow: visible;
  user-select: none;
  -webkit-user-select: none;
}
.ab-chart .abc-gl { stroke: var(--ab-hair); stroke-width: 1; }
.ab-chart .abc-zero { stroke: var(--ab-rule); stroke-width: 1; }
.ab-chart .abc-ax { stroke: var(--ab-rule); stroke-width: 1.25; }
.ab-chart .abc-tk { stroke: var(--ab-rule); stroke-width: 1; }
.ab-chart .abc-tick {
  fill: var(--ab-muted);
  font: 11px var(--ab-font-mono);
}
.ab-chart .abc-tick { font-variant-numeric: tabular-nums; }
.ab-chart .abc-tick-cat { font-family: var(--ab-font-ui); font-size: 11.5px; }
.ab-chart .abc-atitle { fill: var(--ab-ink); font: 600 12px var(--ab-font-ui); }
.ab-chart .abc-fit {
  fill: none;
  stroke: var(--abc-c);
  stroke-width: 2.25;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.ab-chart .abc-bound {
  fill: none;
  stroke: var(--ab-muted);
  stroke-width: 1.4;
  stroke-dasharray: 6 5;
  stroke-linecap: round;
}
.ab-chart .abc-path {
  fill: none;
  stroke: var(--abc-c);
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.ab-chart .abc-path-faint { stroke-opacity: 0.32; stroke-width: 1.5; }
.ab-chart .abc-eb { stroke: var(--ab-ink); stroke-opacity: 0.5; stroke-width: 1.2; stroke-linecap: round; }
.ab-chart .abc-pt { fill: var(--abc-c); stroke: var(--ab-card); stroke-width: 2; }
.ab-chart .abc-bar { fill: var(--abc-c); }
.ab-chart .abc-vlabel {
  fill: var(--ab-ink);
  font: 500 11px var(--ab-font-mono);
}
.ab-chart .abc-vlabel { font-variant-numeric: tabular-nums; }
.ab-chart .abc-plabel { fill: var(--ab-muted); font: 11px var(--ab-font-mono); }
.ab-chart .abc-far { fill: none; stroke: var(--ab-warn); stroke-width: 1.75; }
.ab-chart .abc-ring { fill: none; stroke: var(--abc-c); stroke-width: 2; }
.ab-chart .abc-key-ico .abc-pt { stroke-width: 1.5; }

/* The best-fit line draws itself in once, on the reply that just arrived. */
.ab-chart .abc-anim {
  stroke-dasharray: 1;
  stroke-dashoffset: 1;
  animation: abc-draw 0.9s cubic-bezier(0.4, 0, 0.2, 1) 0.15s forwards;
}
@keyframes abc-draw { to { stroke-dashoffset: 0; } }

.ab-chart .abc-plot-empty {
  margin: 0;
  padding: 36px 12px;
  text-align: center;
  color: var(--ab-muted);
  font-size: 13.5px;
  border: 1px dashed var(--ab-rule);
  border-radius: var(--ab-radius-sm);
}

/* Hover / keyboard readout: the value first, then what it belongs to. */
.ab-chart .abc-tip {
  position: absolute;
  z-index: 2;
  display: flex; flex-direction: column; gap: 1px;
  padding: 6px 10px;
  border: 1px solid var(--ab-rule);
  border-radius: var(--ab-radius-sm);
  background: var(--ab-card);
  box-shadow: 0 6px 18px -6px rgb(0 0 0 / 0.22);
  color: var(--ab-ink);
  font: 12px/1.35 var(--ab-font-ui);
  white-space: nowrap;
  pointer-events: none;
}
.ab-chart .abc-tip[hidden] { display: none; }
.ab-chart .abc-tip-v { font: 600 12.5px/1.35 var(--ab-font-mono); }
.ab-chart .abc-tip-v { font-variant-numeric: tabular-nums; }
.ab-chart .abc-tip-u,
.ab-chart .abc-tip-s { color: var(--ab-muted); font-size: 11.5px; }
.ab-chart .abc-tip-u { font-family: var(--ab-font-mono); }

.ab-chart .abc-note { margin: 8px 0 0; font-size: 12.5px; color: var(--ab-muted); }
.ab-chart .abc-note-tag {
  display: inline-block;
  padding: 5px 10px;
  border-radius: 999px;
  background: var(--ab-warn-soft);
  color: var(--ab-warn);
  font: 600 10.5px/1 var(--ab-font-mono);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.ab-chart .abc-note-tag.abc-note-yours { background: var(--ab-good-soft); color: var(--ab-good); }

/* ── The numbers ──────────────────────────────────────────────────────── */
.ab-chart .abc-stats:empty { display: none; }
.ab-chart .abc-tiles {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 8px;
  margin-top: 12px;
}
.ab-chart .abc-tile {
  display: flex; flex-direction: column; gap: 2px;
  min-width: 0;
  padding: 10px 12px 11px;
  border-radius: var(--ab-radius-sm);
  background: var(--ab-paper);
}
.ab-chart .abc-tile-calc { background: var(--ab-calc-soft); }
.ab-chart .abc-k { font: 500 12px/1.3 var(--ab-font-ui); color: var(--ab-muted); }
.ab-chart .abc-v {
  font: 600 17px/1.3 var(--ab-font-ui);
  color: var(--ab-ink);
  overflow-wrap: anywhere;
}
.ab-chart .abc-tile-calc .abc-num { color: var(--ab-calc); }
.ab-chart .abc-unit { font-size: 13px; font-weight: 500; color: var(--ab-muted); }
.ab-chart .abc-sub { font-size: 12px; line-height: 1.35; color: var(--ab-muted); }
.ab-chart .abc-chip {
  align-self: flex-start;
  margin-top: 5px;
  padding: 4px 9px;
  border-radius: 999px;
  font: 600 11px/1.1 var(--ab-font-ui);
  white-space: nowrap;
}
.ab-chart .abc-ok { background: var(--ab-good-soft); color: var(--ab-good); }
.ab-chart .abc-bad { background: var(--ab-warn-soft); color: var(--ab-warn); }

/* ── Flags: what to check, in plain words ─────────────────────────────── */
/* body:not(#_): the chat's list rules (indent, markers, item gaps) outrank a class. */
body:not(#_) .ab-chart .abc-flags {
  display: flex; flex-direction: column; gap: 6px;
  margin: 12px 0 0;
  padding: 0;
  list-style: none;
}
body:not(#_) .ab-chart .abc-flags[hidden] { display: none; }
body:not(#_) .ab-chart .abc-flag::marker { content: none; }
body:not(#_) .ab-chart .abc-flag {
  display: flex; align-items: flex-start; gap: 8px;
  margin: 0;
  padding: 8px 11px;
  border-radius: var(--ab-radius-sm);
  font-size: 13.5px;
  line-height: 1.45;
}
.ab-chart .abc-flag p { margin: 0; min-width: 0; }
.ab-chart .abc-flag b { font-weight: 600; }
.ab-chart .abc-flag-warn { background: var(--ab-warn-soft); color: var(--ab-ink); }
.ab-chart .abc-flag-warn b { color: var(--ab-warn); }
.ab-chart .abc-flag-info { background: var(--ab-paper); color: var(--ab-muted); }
.ab-chart .abc-flag-info b { color: var(--ab-ink); }
.ab-chart .abc-flag-ico {
  flex: none;
  margin-top: 2px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.5;
  stroke-linecap: round;
  color: var(--ab-muted);
}
.ab-chart .abc-flag-warn .abc-flag-ico { color: var(--ab-warn); }
.ab-chart .abc-flag-ico .abc-dot { fill: currentColor; stroke: none; }

/* ── Show data ────────────────────────────────────────────────────────── */
.ab-chart .abc-data { margin-top: 10px; }
.ab-chart .abc-data[hidden] { display: none; }
.ab-chart .abc-data > summary {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 5px 12px 5px 10px;
  margin-left: -10px;
  border-radius: 999px;
  color: var(--ab-muted);
  font: 500 13px/1.3 var(--ab-font-ui);
  list-style: none;
  cursor: pointer;
}
.ab-chart .abc-data > summary::-webkit-details-marker { display: none; }
.ab-chart .abc-data > summary::before {
  content: '';
  width: 6px; height: 6px;
  margin: 0 1px 0 2px;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  border-radius: 0 0 1.5px 0;
  transform: rotate(-45deg);
  transition: transform 0.15s ease;
}
.ab-chart .abc-data[open] > summary::before { transform: rotate(45deg) translate(-1px, -1px); }
.ab-chart .abc-data > summary:hover { color: var(--ab-ink); background: var(--ab-paper); }
.ab-chart .abc-data > summary:focus-visible { outline: 2px solid var(--ab-calc); outline-offset: 1px; }
.ab-chart .abc-data-bar {
  display: flex; flex-wrap: wrap; align-items: center;
  gap: 6px 12px;
  margin: 8px 0;
}
.ab-chart .abc-data-hint { font-size: 12px; color: var(--ab-muted); }
.ab-chart .abc-btn {
  padding: 7px 13px;
  border: 1px solid var(--ab-rule);
  border-radius: 999px;
  background: transparent;
  color: var(--ab-ink);
  font: 500 12.5px/1 var(--ab-font-ui);
  cursor: pointer;
}
.ab-chart .abc-btn:hover { background: var(--ab-paper); border-color: var(--ab-muted); }
.ab-chart .abc-btn:focus-visible { outline: 2px solid var(--ab-calc); outline-offset: 2px; }

/* Tables (the data, and one row per set). The chat's own table rules are
   stronger than a class (styles.css: zebra rows, a tinted header, display:
   block), so these carry body:not(#_) the way chatclean.css does. */
body:not(#_) .ab-chart .abc-table-wrap {
  overflow-x: auto;
  border: 1px solid var(--ab-hair);
  border-radius: var(--ab-radius-sm);
  background: var(--ab-card);
}
body:not(#_) .ab-chart .abc-stats-table { margin-top: 12px; }
body:not(#_) .ab-chart .abc-table {
  display: table;
  width: 100%;
  margin: 0;
  border: 0;
  border-radius: 0;
  border-collapse: collapse;
  overflow: visible;
  font: 12.5px/1.4 var(--ab-font-mono);
}
body:not(#_) .ab-chart .abc-table { font-variant-numeric: tabular-nums; }
body:not(#_) .ab-chart .abc-table th,
body:not(#_) .ab-chart .abc-table td {
  padding: 6px 12px;
  border: 0;
  border-bottom: 1px solid var(--ab-hair);
  background: transparent;
  color: var(--ab-ink);
  font-weight: 400;
  text-align: right;
  vertical-align: middle;
  white-space: nowrap;
}
body:not(#_) .ab-chart .abc-table thead { position: static; }
body:not(#_) .ab-chart .abc-table thead th {
  background: var(--ab-paper);
  color: var(--ab-muted);
  font: 600 11.5px/1.3 var(--ab-font-ui);
  border-bottom: 1px solid var(--ab-rule);
}
body:not(#_) .ab-chart .abc-table tbody tr { background: transparent; }
body:not(#_) .ab-chart .abc-table tbody tr:hover > * { background: var(--ab-paper); }
body:not(#_) .ab-chart .abc-table tbody th { color: var(--ab-muted); text-align: center; }
body:not(#_) .ab-chart .abc-table tr:last-child > * { border-bottom: 0; }
body:not(#_) .ab-chart .abc-table .abc-txt { text-align: left; font-family: var(--ab-font-ui); }
body:not(#_) .ab-chart .abc-table .abc-calc { color: var(--ab-calc); }
body:not(#_) .ab-chart .abc-table .abc-muted { color: var(--ab-muted); text-align: left; }
body:not(#_) .ab-chart .abc-table .abc-row-far > * { background: var(--ab-warn-soft); }
body:not(#_) .ab-chart .abc-table .abc-chip { margin: 0 0 0 6px; padding: 2px 7px; font-size: 10.5px; vertical-align: 1px; }
body:not(#_) .ab-chart .abc-table .abc-set-cell { text-align: left; font-family: var(--ab-font-ui); color: var(--ab-ink); }
body:not(#_) .ab-chart .abc-stats-table thead th:first-child { text-align: left; }
body:not(#_) .ab-chart .abc-table .abc-eq { font-size: 15px; white-space: nowrap; }

/* ── Check your data ─────────────────────────────────────────────────── */
.ab-chart .abc-edit {
  display: flex; flex-direction: column; gap: 8px;
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid var(--ab-hair);
}
.ab-chart .abc-edit-head {
  display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between;
  gap: 2px 12px;
}
.ab-chart .abc-edit-title { font: 600 14px/1.35 var(--ab-font-ui); color: var(--ab-ink); }
.ab-chart .abc-edit-status { font-size: 12.5px; color: var(--ab-muted); font-variant-numeric: tabular-nums; }
.ab-chart .abc-edit-hint { margin: 0; max-width: 64ch; font-size: 13px; line-height: 1.45; color: var(--ab-muted); }
.ab-chart .abc-ta {
  box-sizing: border-box;
  width: 100%;
  min-height: 112px;
  margin: 0;
  padding: 10px 12px;
  resize: vertical;
  border: 1px solid var(--ab-rule);
  border-radius: var(--ab-radius-sm);
  background: var(--ab-paper);
  color: var(--ab-ink);
  font: 12.5px/1.6 var(--ab-font-mono);
  white-space: pre;
  overflow-x: auto;
  tab-size: 14;
  box-shadow: none;
}
.ab-chart .abc-ta { font-variant-numeric: tabular-nums; }
.ab-chart .abc-ta:focus { outline: none; }
.ab-chart .abc-ta:focus-visible { border-color: var(--ab-calc); box-shadow: 0 0 0 3px var(--ab-calc-soft); }
.ab-chart .abc-edit-bar { display: flex; flex-wrap: wrap; gap: 8px; }

/* ── Nothing to draw ─────────────────────────────────────────────────── */
.ab-chart .abc-empty-msg { margin: 6px 0 0; color: var(--ab-muted); font-size: 13.5px; }
.ab-chart .abc-src summary { margin-top: 6px; color: var(--ab-muted); font-size: 12.5px; cursor: pointer; }
.ab-chart .abc-src pre {
  margin: 8px 0 0;
  padding: 10px;
  overflow-x: auto;
  white-space: pre-wrap;
  border-radius: var(--ab-radius-sm);
  background: var(--ab-paper);
  font: 12px/1.45 var(--ab-font-mono);
}

/* ── Phones ──────────────────────────────────────────────────────────── */
@media (max-width: 560px) {
  .ab-chart { margin: 14px 0; padding: 12px 10px 10px; }
  .ab-chart .abc-tiles { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 6px; }
  .ab-chart .abc-tile { padding: 9px 10px 10px; }
  .ab-chart .abc-v { font-size: 15.5px; }
  .ab-chart .abc-eq { font-size: 16px; white-space: normal; }
  .ab-chart .abc-data-hint { display: none; }
  .ab-chart .abc-ta { font-size: 16px; }   /* under 16px, iOS zooms the page on focus */
}

@media (prefers-reduced-motion: reduce) {
  .ab-chart .abc-anim { animation: none; stroke-dasharray: none; stroke-dashoffset: 0; }
  .ab-chart .abc-data > summary::before { transition: none; }
}

@media (forced-colors: active) {
  .ab-chart .abc-pt, .ab-chart .abc-bar { fill: CanvasText; stroke: Canvas; }
  .ab-chart .abc-fit, .ab-chart .abc-path { stroke: Highlight; }
  .ab-chart .abc-bound, .ab-chart .abc-eb, .ab-chart .abc-ax { stroke: CanvasText; }
  .ab-chart .abc-tick, .ab-chart .abc-atitle { fill: CanvasText; }
}