/* Figure 7. Two clocks: which product changes sign.
   Every class is prefixed wc7- and every token is scoped to the figure. */
.wc7 {
  --wc-paper: #faf8f3; --wc-ink: #1d1d1b; --wc-body: #2a2926; --wc-soft: #3c3a36; --wc-hair: #8a8a8a; --wc-hair-text: #6b6b6b;
  --wc-rule: color-mix(in srgb, var(--wc-ink) 16%, var(--wc-paper));
  --wc-c: #009fe3; --wc-m: #e6007e; --wc-c-text: #0072b5; --wc-m-text: #c4006b;
  --wc-text: "InterVariable", "Inter", -apple-system, "Helvetica Neue", Arial, sans-serif;
  --wc-display: "Inter Display", "InterVariable", "Inter", -apple-system, "Helvetica Neue", Arial, sans-serif;
  --wc-mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
  margin: 0; padding: clamp(1rem, 2.4vw, 1.75rem); background: var(--wc-paper); color: var(--wc-body);
  border: 1px solid var(--wc-ink); font-family: var(--wc-text); font-weight: 420; line-height: 1.42;
  font-optical-sizing: auto; box-sizing: border-box; container-type: inline-size;
}
.wc7[data-frame="none"] { border: 0; padding: 0; background: transparent; }
@media screen and (prefers-color-scheme: dark) {
  .wc7 { --wc-paper: #141413; --wc-ink: #faf8f3; --wc-body: #e9e6df; --wc-soft: #c9c5bc; --wc-hair: #8a8a8a; --wc-hair-text: #8a8a8a;
    --wc-c: #2bb3f0; --wc-m: #ff3d9e; --wc-c-text: #2bb3f0; --wc-m-text: #ff6fb6; }
}
.wc7 *, .wc7 *::before, .wc7 *::after { box-sizing: border-box; }
.wc7-label { margin: 0; font: 700 .72rem/1.3 var(--wc-mono); letter-spacing: .14em; text-transform: uppercase; color: var(--wc-soft); }
.wc7-m { text-transform: none; letter-spacing: .02em; font-family: var(--wc-text); font-weight: 600; font-style: italic; }
.wc7-m sup { font-size: .72em; font-style: normal; }
.wc7-head { display: flex; flex-wrap: wrap; justify-content: space-between; gap: .5rem 1rem; align-items: baseline;
  padding-bottom: .75rem; border-bottom: 1px solid var(--wc-rule); }
.wc7-live { color: var(--wc-ink); }
.wc7-live::before { content: ""; display: inline-block; width: .5rem; height: .5rem; margin-right: .45rem; background: var(--wc-ink); vertical-align: .05rem; }

.wc7-lede { margin: .8rem 0 0; max-width: 52rem; font-size: 1.05rem; font-weight: 450; line-height: 1.32; color: var(--wc-ink); }
.wc7-top { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr) minmax(15rem, 1.15fr); gap: clamp(1rem, 2.2vw, 1.8rem); padding-top: 1rem; align-items: start; }
.wc7-reg, .wc7-prod { min-width: 0; }
.wc7-ring { display: block; width: 100%; max-width: 230px; height: auto; margin: .3rem auto 0; overflow: visible; }
.wc7-zp { display: block; width: 100%; max-width: 150px; height: auto; margin: .4rem auto 0; overflow: visible; }
.wc7-zp--big { max-width: 190px; margin-left: 0; }
.wc7-zline { margin: .3rem 0 0; text-align: center; font: 400 .74rem/1.4 var(--wc-mono); color: var(--wc-ink); }
.wc7-prod { border-top: 1px solid var(--wc-ink); padding-top: .8rem; }
.wc7-big { display: flex; align-items: baseline; gap: .6rem; flex-wrap: wrap; margin: .5rem 0 .2rem; color: var(--wc-ink); }
.wc7-num { font-family: var(--wc-display); font-weight: 860; font-size: clamp(2.4rem, 4.6vw, 3.4rem); line-height: .86; letter-spacing: -.04em; white-space: nowrap; }
.wc7-num i, .wc7-num .wc7-m { font-style: italic; font-weight: 780; font-family: var(--wc-display); }
.wc7-unit { font: 700 .72rem/1.3 var(--wc-mono); letter-spacing: .12em; text-transform: uppercase; color: var(--wc-soft); }
.wc7-sub { margin: .5rem 0 0; font-size: 1rem; line-height: 1.34; color: var(--wc-ink); }
.wc7-check { margin: .6rem 0 0; font: 400 .74rem/1.5 var(--wc-mono); color: var(--wc-soft); font-variant-numeric: tabular-nums; }
.wc7-check b { color: var(--wc-ink); }
.wc7-check sub, .wc7-caption sub, .wc7-label sub, .wc7-zline sub { font-size: .72em; }
.wc7-controls { display: flex; flex-wrap: wrap; gap: .45rem; margin-top: .9rem; }
.wc7-controls button { appearance: none; border: 1px solid var(--wc-ink); border-radius: 0; background: transparent; color: var(--wc-ink); cursor: pointer;
  font: 700 .66rem/1 var(--wc-mono); letter-spacing: .1em; text-transform: uppercase; padding: .6rem .7rem; min-height: 40px; min-width: 44px; }
.wc7-controls button.is-main { background: var(--wc-ink); color: var(--wc-paper); }
.wc7-controls button:hover { background: color-mix(in srgb, var(--wc-ink) 10%, transparent); }
.wc7-controls button.is-main:hover { background: color-mix(in srgb, var(--wc-ink) 84%, var(--wc-paper)); }
.wc7-controls button:focus-visible { outline: 2px solid var(--wc-ink); outline-offset: 2px; }
.wc7-real { margin-top: 1.2rem; padding-top: .9rem; border-top: 1px solid var(--wc-rule); }
.wc7-grids { display: grid; grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr) auto minmax(0, 1fr); gap: .6rem; align-items: center; margin-top: .5rem; }
.wc7-gridbox { min-width: 0; }
.wc7-grid { display: block; width: 100%; max-width: 220px; height: auto; margin: .3rem 0 0; }
.wc7-gline { margin: .3rem 0 0; font: 400 .72rem/1.4 var(--wc-mono); color: var(--wc-soft); min-height: 2.8em; }
.wc7-gline b { color: var(--wc-ink); }
.wc7-op { margin: 0; font-family: var(--wc-display); font-weight: 400; font-size: 2rem; color: var(--wc-soft); }
.wc7-key { display: flex; flex-wrap: wrap; gap: .25rem 1rem; margin: .4rem 0 0; padding: 0; list-style: none; font: 400 .72rem/1.35 var(--wc-mono); color: var(--wc-soft); }
.wc7-key i { display: inline-block; width: .7rem; height: .7rem; margin-right: .35rem; vertical-align: -.05rem; }
.wc7-key .kp { background: var(--wc-ink); } .wc7-key .kn { background: var(--wc-m); }
.wc7-caption { margin: 1rem 0 0; padding-top: .8rem; border-top: 1px solid var(--wc-rule); font-size: .95rem; color: var(--wc-body); max-width: 50rem; }
.wc7-caption p { margin: 0; } .wc7-caption p + p { margin-top: .5rem; }
.wc7-sr { position: absolute; width: 1px; height: 1px; margin: -1px; padding: 0; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
.wc7 svg text { font-family: var(--wc-mono); fill: var(--wc-soft); }
.wc7 .t-val { font-family: var(--wc-text); font-weight: 650; fill: var(--wc-ink); }
.wc7 .t-pos { fill: var(--wc-hair-text); }   /* small grey digits: 4.5:1 on the paper */
.wc7 .t-math { font-family: var(--wc-text); font-style: italic; font-weight: 600; fill: var(--wc-ink); }
.wc7 .t-i { fill: var(--wc-c-text); }
.wc7 .ln-rule { stroke: var(--wc-rule); fill: none; }
.wc7 .ln-ink { stroke: var(--wc-ink); fill: none; }
.wc7 .node { fill: var(--wc-paper); stroke: var(--wc-ink); }
.wc7 .bar-p { stroke: var(--wc-ink); } .wc7 .bar-m { stroke: var(--wc-m); }
.wc7 .zarr { stroke: var(--wc-ink); fill: none; } .wc7 .zarrh { fill: var(--wc-ink); }
.wc7 .turn { stroke: var(--wc-c); fill: none; }
.wc7-nw { white-space: nowrap; }
/* large reader text (the figure narrower than 13 of its text widths): an item may break after "=", never inside a + bi */
@container (max-width: 13rem) { .wc7-nw { white-space: normal; } }
.wc7-key .kz { height: 0; border-top: 2.5px solid var(--wc-ink); vertical-align: .2rem; }
.wc7-key .kg { height: 0; border-top: 1.5px solid var(--wc-hair); vertical-align: .2rem; }
.wc7-key .kt { height: .6rem; border: 1.8px solid var(--wc-c); border-radius: 50% 50% 0 0; border-bottom: 0; vertical-align: 0; }
.wc7 .zprev { stroke: var(--wc-hair); fill: none; } .wc7 .zprevh { fill: var(--wc-hair); }
.wc7 .cell { fill: none; stroke: var(--wc-rule); }
.wc7 .sq-p { fill: var(--wc-ink); } .wc7 .sq-m { fill: var(--wc-m); }
@container (max-width: 900px) {
  .wc7-top { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .wc7-prod { grid-column: 1 / -1; }
}
@container (max-width: 640px) {
  .wc7-grids { grid-template-columns: minmax(0, 1fr); }
  .wc7-op { display: none; }
  .wc7-grid { max-width: 260px; }
}
@media (forced-colors: active) {
  .wc7 { border-color: CanvasText; }
  .wc7 .bar-p, .wc7 .zarr, .wc7 .ln-ink, .wc7 .node { stroke: CanvasText; }
  .wc7 .bar-m { stroke: CanvasText; stroke-dasharray: 2 2; }
  .wc7 .zarrh, .wc7 .sq-p { fill: CanvasText; }
  .wc7 .sq-m { fill: Canvas; stroke: CanvasText; stroke-width: 1; }
  .wc7 .zprev { stroke: GrayText; } .wc7 .zprevh { fill: GrayText; }
  .wc7 .turn { stroke: CanvasText; }
  .wc7-key .kz, .wc7-key .kt { border-color: CanvasText; } .wc7-key .kg { border-color: GrayText; }
  .wc7 svg text, .wc7 .t-i { fill: CanvasText; } .wc7 .node { fill: Canvas; }
  .wc7-key .kp, .wc7-key .kn { forced-color-adjust: none; background: CanvasText; } .wc7-key .kn { background: Canvas; border: 1px solid CanvasText; }
  .wc7-controls button.is-main { background: ButtonText; color: ButtonFace; forced-color-adjust: none; }
}
@media print {
  .wc7, .wc7 * { -webkit-print-color-adjust: exact; print-color-adjust: exact; }
  .wc7 { --wc-paper: #ffffff; --wc-ink: #1d1d1b; --wc-body: #2a2926; --wc-soft: #3c3a36; --wc-c: #0072b5; --wc-m: #c4006b; border-color: #1d1d1b; }
  .wc7-controls { display: none; }
}
.wc7-dash { font-weight: 300; }
/* labels in the small planes keep a paper halo, so a grey "before" arrow under one does not lower its contrast */
.wc7 .wc7-zp text { paint-order: stroke; stroke: var(--wc-paper); stroke-width: 3px; stroke-linejoin: round; }
@media (forced-colors: active) { .wc7 .wc7-zp text { stroke: Canvas; } }