/* Figure 3. Twice is none: k crossings in one window; the window posts exactly when k is odd.
   Every class is prefixed cat3- and every token is scoped to the figure. */
.cat3 {
  --k-paper: var(--cat-paper, #faf8f3); --k-ink: var(--cat-ink, #1d1d1b); --k-body: var(--cat-body, #2a2926); --k-soft: var(--cat-soft, #3c3a36);
  --k-hair: var(--cat-hair, #8a8a8a); --k-zero: var(--cat-zero, #6f6d68); --k-rule: var(--cat-rule, color-mix(in srgb, var(--k-ink) 16%, var(--k-paper)));
  --k-c: #009fe3; --k-m: #e6007e; --k-c-text: #0072b5; --k-m-text: #c4006b;
  --k-text: var(--cat-text, "InterVariable", "Inter", -apple-system, "Helvetica Neue", Arial, sans-serif);
  --k-display: var(--cat-display, "Inter Display", "InterVariable", "Inter", -apple-system, "Helvetica Neue", Arial, sans-serif);
  --k-mono: var(--cat-mono, "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace);
  margin: 0; padding: clamp(.85rem, 2vw, 1.5rem); background: var(--k-paper); color: var(--k-body);
  border: 1px solid var(--k-ink); font-family: var(--k-text); font-weight: 420; line-height: 1.42;
  font-optical-sizing: auto; box-sizing: border-box; position: relative;
}
@media screen and (prefers-color-scheme: dark) {
  .cat3 { --k-paper: var(--cat-paper, #141413); --k-ink: var(--cat-ink, #faf8f3); --k-body: var(--cat-body, #e9e6df); --k-soft: var(--cat-soft, #c9c5bc);
    --k-c: #2bb3f0; --k-m: #ff3d9e; --k-c-text: #2bb3f0; --k-m-text: #ff6fb6; --k-zero: var(--cat-zero, #8a8a8a); }
}
.cat3 *, .cat3 *::before, .cat3 *::after { box-sizing: border-box; }
.cat3-label { margin: 0; font: 700 .72rem/1.3 var(--k-mono); letter-spacing: .14em; text-transform: uppercase; color: var(--k-soft); }
.cat3-head { display: flex; flex-wrap: wrap; justify-content: space-between; gap: .5rem 1rem; align-items: center;
  padding-bottom: .75rem; border-bottom: 1px solid var(--k-rule); }
.cat3-head .cat3-live { color: var(--k-ink); }
.cat3-live::before { content: ""; display: inline-block; width: .5rem; height: .5rem; margin-right: .45rem; background: var(--k-m); vertical-align: .05rem; }
.cat3[data-paused="true"] .cat3-live::before { background: transparent; border: 1px solid var(--k-ink); }
.cat3-btns { display: flex; flex-wrap: wrap; gap: .4rem; }
.cat3 button { appearance: none; border: 1px solid var(--k-ink); border-radius: 0; background: transparent; color: var(--k-ink); cursor: pointer;
  display: inline-flex; align-items: center; justify-content: center; min-height: 36px; padding: 0 .7rem;
  font: 700 .64rem/1 var(--k-mono); letter-spacing: .1em; text-transform: uppercase; }
.cat3 button:hover { background: color-mix(in srgb, var(--k-ink) 8%, transparent); }
.cat3 button:focus-visible { outline: 2px solid var(--k-ink); outline-offset: 2px; }
.cat3 button[aria-disabled="true"] { opacity: .4; cursor: default; }
.cat3-grid { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr); gap: clamp(1rem, 2.6vw, 2.25rem); padding-top: 1rem; align-items: start; }
.cat3-stage { min-width: 0; }
.cat3-svg { display: block; width: 100%; max-width: 600px; height: auto; overflow: visible; }
.cat3-svg text { font-family: var(--k-mono); font-weight: 700; font-size: 8px; letter-spacing: .1em; fill: var(--k-soft); }
.cat3-svg .t-c { fill: var(--k-c-text); } .cat3-svg .t-m { fill: var(--k-m-text); } .cat3-svg .t-ink { fill: var(--k-ink); }
.cat3-svg .brk { fill: none; stroke: var(--k-ink); stroke-width: .9; }
.cat3-svg .track-c { stroke: var(--k-c); stroke-width: 1; stroke-dasharray: 3 2; } .cat3-svg .track-m { stroke: var(--k-m); stroke-width: 1; stroke-dasharray: 3 2; }
.cat3-svg .cross { stroke: var(--k-hair); stroke-width: .8; }
.cat3-svg .path { fill: none; stroke: var(--k-ink); stroke-width: 2.2; stroke-linejoin: round; }
.cat3-svg .start { fill: var(--k-ink); }
.cat3-svg .end { stroke: var(--k-ink); stroke-width: 1.2; } .cat3-svg .end.c { fill: var(--k-c); } .cat3-svg .end.m { fill: var(--k-m); }
.cat3-ctl { display: flex; align-items: center; gap: .6rem; margin-top: .6rem; }
.cat3-ctl button { white-space: nowrap; }
.cat3-ctl output { min-width: 8.5rem; text-align: center; font: 400 .95rem/1 var(--k-mono); color: var(--k-ink); font-variant-numeric: tabular-nums; }
.cat3-panel { min-width: 0; display: flex; flex-direction: column; gap: .9rem; }
.cat3-verdict { border-top: 3px solid var(--k-ink); padding-top: .55rem; }
.cat3-big { margin: .3rem 0 .3rem; font-family: var(--k-display); font-weight: 820; font-size: clamp(1.7rem, 3.2vw, 2.4rem); line-height: .95; letter-spacing: -.035em; color: var(--k-ink); }
.cat3-big.c { color: var(--k-c-text); } .cat3-big.m { color: var(--k-m-text); }
.cat3-say { margin: 0; font-size: .95rem; line-height: 1.4; color: var(--k-body); }
.cat3-mat .cat3-label, .cat3-state .cat3-label { font-size: .62rem; margin-bottom: .3rem; }
.cat3-mat sup { font-size: .75em; letter-spacing: 0; }
.cat3-grid6 { display: grid; grid-template-columns: repeat(6, 2rem); border-left: 2px solid var(--k-ink); border-right: 2px solid var(--k-ink); padding: .1rem .2rem; width: max-content; }
.cat3-grid6 span { padding: .18rem 0; text-align: center; font: 400 .78rem/1.1 var(--k-mono); color: var(--k-zero); }
.cat3-grid6 span.d { color: var(--k-c-text); font-weight: 700; } .cat3-grid6 span.x { color: var(--k-m-text); font-weight: 700; }
.cat3-sides { display: flex; font: 700 .58rem/1.2 var(--k-mono); letter-spacing: .12em; text-transform: uppercase; color: var(--k-soft); margin: 0 0 .05rem; }
.cat3-sides span { width: 9.9rem; } .cat3-sides span + span { margin-left: .7rem; }
.cat3-cells { display: flex; align-items: center; }
.cat3-cell { display: flex; flex-direction: column; align-items: center; width: 3.3rem; min-width: 0; }
.cat3-cell svg { display: block; width: 30px; height: 30px; overflow: visible; }
.cat3-cell svg circle { fill: none; stroke: var(--k-hair); stroke-width: 1; }
.cat3-cell svg .dot { fill: var(--k-hair); stroke: none; }
.cat3-cell svg line { stroke-width: 2; stroke-linecap: round; } .cat3-cell svg line.c { stroke: var(--k-c); } .cat3-cell svg line.m { stroke: var(--k-m); }
.cat3-cell span { margin-top: .1rem; font: 400 .74rem/1.2 var(--k-mono); color: var(--k-ink); white-space: nowrap; }
.cat3-cut { align-self: stretch; width: 0; margin: 0 .35rem; border-left: 1px dashed var(--k-ink); }
.cat3-over { margin-left: .5rem; font: 400 .74rem/1 var(--k-mono); color: var(--k-soft); white-space: nowrap; }
.cat3-fine sup { font-size: .75em; }
.cat3-fine { margin: .9rem 0 0; padding-top: .7rem; border-top: 1px solid var(--k-rule); font-size: .86rem; line-height: 1.4; color: var(--k-soft); max-width: 60rem; }
.cat3-sr { position: absolute; width: 1px; height: 1px; margin: -1px; padding: 0; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
@media (max-width: 860px) {
  .cat3-grid { grid-template-columns: minmax(0, 1fr); }
  .cat3-svg text { font-size: 12px; }
}
@media (max-width: 420px) {
  .cat3-ctl { gap: .4rem; } .cat3-ctl output { min-width: 0; flex: 1; font-size: .85rem; } .cat3-ctl button { padding: 0 .5rem; }
  .cat3-cell { width: 2.75rem; } .cat3-cell span { font-size: .66rem; } .cat3-sides span { width: 8.25rem; }
}
@media (max-width: 340px) {
  .cat3-ctl { flex-wrap: wrap; } .cat3-ctl output { order: -1; flex: 1 0 100%; text-align: left; }
}
@media (prefers-reduced-motion: reduce) { .cat3 * { transition: none !important; animation: none !important; } }
@media (forced-colors: active) {
  .cat3 { forced-color-adjust: none; --k-paper: Canvas; --k-ink: CanvasText; --k-body: CanvasText; --k-soft: CanvasText; --k-hair: GrayText; --k-zero: GrayText;
    --k-c: Highlight; --k-m: LinkText; --k-c-text: CanvasText; --k-m-text: CanvasText; --k-rule: GrayText; }
}
@media print { .cat3 { --k-paper: #fff; --k-ink: #000; --k-body: #000; --k-soft: #222; --k-zero: #555; print-color-adjust: exact; -webkit-print-color-adjust: exact; } .cat3-ctl { display: none; } }
@media print {
  /* on paper a figure starts on the page that holds its head row and first block; its blocks are not split */
  .cat3-head { break-after: avoid; break-inside: avoid; }
  .cat3-grid { padding-top: 0; margin-top: .8rem; break-before: avoid; }
  .cat3-grid > *, .cat3-grid > * > * { break-inside: avoid; }
}