/* Why Space Has Three Dimensions. Screen style from the design stack, in the family of /recognition-geometry/:
   warm paper and ink, Inter display headlines, mono instrument labels, square corners, no gradients or soft shadows.
   One meaning per ink across the page:
     ink      the mark: the loop that stays put, and the cube's trunk roads
     magenta  the reader: the loop you move, and the walk you take on the cube
     cyan     the count: the soap film and its pokes, the leftover roads the tally counts
     red      a move stopped, where one loop would have to cut or cross the other
     yellow   the fourth direction */
body.sp-body[data-rpi-page] {
  --sp-paper: #faf8f3; --sp-ink: #1d1d1b; --sp-body: #2a2926; --sp-soft: #3c3a36; --sp-muted: #5f5b53;
  --sp-hair: #8a8a8a; --sp-rule: #d9d5cb; --sp-panel: #f3f0e8;
  --sp-cyan: #009fe3; --sp-magenta: #e6007e; --sp-yellow: #ffed00; --sp-red: #c8401f; --sp-green: #0b7a3e;
  --sp-film: rgba(0, 159, 227, .13);
  /* The same inks, deeper, for small text on paper (4.6:1 or better). Lines and shapes keep the inks above. */
  --sp-cyan-text: #0473a5; --sp-magenta-text: #c4006b; --sp-red-text: #b23a1b;
  --sp-display: "Inter Display", "InterVariable", "Inter", -apple-system, "Helvetica Neue", Arial, sans-serif;
  --sp-text: "InterVariable", "Inter", -apple-system, "Helvetica Neue", Arial, sans-serif;
  --sp-mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --sp-gutter: 2rem;
  background: var(--sp-paper); color: var(--sp-body); font-optical-sizing: auto;
}
@media (prefers-color-scheme: dark) {
  body.sp-body[data-rpi-page] {
    --sp-paper: #141413; --sp-ink: #faf8f3; --sp-body: #e9e6df; --sp-soft: #c9c5bc; --sp-muted: #aaa59b;
    --sp-hair: #8a8a8a; --sp-rule: #3a3833; --sp-panel: #1c1b19;
    --sp-cyan: #2bb3f0; --sp-magenta: #ff3d9e; --sp-yellow: #ffed00; --sp-red: #ff6a3d; --sp-green: #3fbf7f;
    --sp-film: rgba(43, 179, 240, .16);
    --sp-cyan-text: #2bb3f0; --sp-magenta-text: #ff5aad; --sp-red-text: #ff6a3d;
    color-scheme: dark;
  }
}

.sp-page { font: 420 1.0625rem/1.5 var(--sp-text); color: var(--sp-body); padding-bottom: 2rem; overflow-x: clip; }
.sp-page *, .sp-page *::before, .sp-page *::after { box-sizing: border-box; }
.sp-page p { margin: 0 0 1.1rem; }
.sp-page a { color: var(--sp-ink); text-decoration-thickness: 1px; text-underline-offset: .22em; }
.sp-page a:hover { text-decoration-thickness: 2px; }
body.sp-body[data-rpi-page] .sp-page :is(a, button, input, summary, canvas, svg, video, [tabindex]):focus-visible { outline: 3px solid var(--sp-ink) !important; outline-offset: 3px; }
.sp-body .skip { position: absolute; left: 1rem; top: -10rem; z-index: 80; padding: .8rem 1rem; background: var(--sp-paper); color: var(--sp-ink); border: 1px solid var(--sp-ink); }
.sp-body .skip:focus { top: 1rem; }
.sp-wrap { width: min(calc(100% - 2 * var(--sp-gutter)), 75rem); margin-inline: auto; }
.sp-page [hidden] { display: none !important; }
.sp-vh { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.sp-nowrap { white-space: nowrap; }

/* Type */
.sp-page .sp-eyebrow, .sp-page .sp-k {
  margin: 0 0 1rem; font: 700 .72rem/1.3 var(--sp-mono); letter-spacing: .14em; text-transform: uppercase; color: var(--sp-soft);
}
.sp-page .sp-eyebrow a { color: inherit; text-decoration: none; }
.sp-page .sp-eyebrow a:hover { text-decoration: underline; }
.sp-page .sp-title {
  margin: 0 0 1.3rem; font: 820 clamp(2.6rem, 3.9vw, 3.9rem)/.94 var(--sp-display);
  letter-spacing: -.038em; color: var(--sp-ink); text-shadow: 0 0 .5px color-mix(in srgb, var(--sp-ink) 55%, transparent);
}
.sp-page .sp-lede { margin: 0; font: 450 clamp(1.1rem, 1.3vw, 1.24rem)/1.34 var(--sp-text); letter-spacing: -.008em; color: var(--sp-ink); }
.sp-page .sp-byline { margin: 1.1rem 0 0; font: 400 .78rem/1.4 var(--sp-mono); color: var(--sp-muted); }
.sp-page h2 { margin: 0; font: 780 clamp(1.7rem, 2.6vw, 2.4rem)/1.05 var(--sp-display); letter-spacing: -.02em; color: var(--sp-ink); max-width: 19ch; }
.sp-page h3 { margin: 2rem 0 .7rem; font: 780 1.2rem/1.15 var(--sp-display); letter-spacing: -.015em; color: var(--sp-ink); }
.sp-ph { outline: 1px dashed var(--sp-red); outline-offset: 2px; }

/* ---------- Hero and THE DIAL ---------- */
.sp-hero { padding: 3rem 0 3.4rem; }
.sp-hero-grid {
  display: grid; grid-template-columns: minmax(0, 21rem) minmax(0, 1fr); column-gap: 3.2rem;
  grid-template-areas: "text stage" "panel stage"; grid-template-rows: auto 1fr; align-items: start;
}
.sp-hero-text { grid-area: text; padding-bottom: 1.8rem; }
.sp-stage { grid-area: stage; position: sticky; top: 72px; min-width: 0; }
.sp-panel { grid-area: panel; min-width: 0; }

.sp-panes { position: relative; display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 12.5rem); column-gap: 1.6rem; align-items: start; }
.sp-page .sp-stage-label { display: flex; align-items: center; justify-content: space-between; gap: 1rem; height: 1.4rem; margin: 0 0 .6rem; }
.sp-live { display: inline-flex; align-items: center; gap: .5rem; font: 700 .72rem/1 var(--sp-mono); letter-spacing: .14em; color: var(--sp-ink); }
.sp-live::before { content: ""; width: .5rem; height: .5rem; background: var(--sp-ink); }
.sp-mode-tag { font: 700 .66rem/1 var(--sp-mono); letter-spacing: .12em; text-transform: uppercase; color: var(--sp-muted); }
.sp-canvas-wrap { position: relative; width: 100%; aspect-ratio: 4 / 3; border: 1px solid var(--sp-hair); }
.sp-canvas { display: block; width: 100%; height: 100%; cursor: grab; touch-action: pan-y; -webkit-tap-highlight-color: transparent; }
.sp-canvas.is-dragging { cursor: grabbing; }
.sp-canvas.is-over { cursor: move; }
.sp-page .sp-keyfocus { display: none; margin: .45rem 0 0; font: 400 .74rem/1.4 var(--sp-mono); color: var(--sp-ink); }
.sp-pane-c:focus-within .sp-keyfocus { display: block; }
.sp-page .sp-keyline { display: flex; flex-wrap: wrap; align-items: center; gap: .25rem .2rem; margin: .55rem 0 0; font: 700 .58rem/1.5 var(--sp-mono); letter-spacing: .08em; color: var(--sp-muted); }
.sp-keyline .sp-key { display: inline-flex; align-items: center; gap: .4rem; }
.sp-keyline .sp-key::before { content: ""; flex: none; }
.sp-key-ink::before { width: 1rem; height: 3px; background: var(--sp-ink); }
.sp-key-magenta::before { width: 1rem; height: 3px; background: var(--sp-magenta); }
.sp-key-cyan::before { width: .7rem; height: .7rem; background: var(--sp-film); border: 1.5px solid var(--sp-cyan); }
.sp-key-red::before { width: .6rem; height: .6rem; border-radius: 50%; border: 2px solid var(--sp-red); }
.sp-key-yellow::before { width: 1rem; height: 6px; background: var(--sp-yellow); outline: 1px solid color-mix(in srgb, var(--sp-ink) 25%, transparent); }
.sp-key-sep { padding: 0 .15rem; }

/* The readout beside the canvas */
.sp-pane-q { padding-top: 2rem; }
.sp-page .sp-pane-q .sp-k { margin: 0 0 .5rem; color: var(--sp-ink); }
.sp-page .sp-count { margin: 0; }
.sp-num { display: block; font: 860 clamp(4rem, 7vw, 6.2rem)/.86 var(--sp-display); letter-spacing: -.05em; color: var(--sp-cyan-text); font-variant-numeric: tabular-nums lining-nums; }
.sp-page .sp-sub { margin: .55rem 0 1rem; font: 400 .76rem/1.4 var(--sp-mono); color: var(--sp-muted); }
.sp-page .sp-state { display: inline-block; margin: 0 0 1.1rem; padding: .32rem .55rem; border: 1.5px solid var(--sp-ink); font: 700 .7rem/1.2 var(--sp-mono); letter-spacing: .12em; text-transform: uppercase; color: var(--sp-ink); }
.sp-state[data-state="hooked"] { background: var(--sp-ink); color: var(--sp-paper); }
.sp-state[data-state="lifted"] { background: var(--sp-yellow); color: #1d1d1b; border-color: #1d1d1b; }
.sp-state[data-state="never"] { color: var(--sp-muted); border-color: var(--sp-hair); }
.sp-num[data-off="1"] { color: var(--sp-muted); font-weight: 300; }

.sp-page .sp-caption { min-height: 3em; margin: 1rem 0 0; padding-top: .8rem; border-top: 1.5px solid var(--sp-ink); font: 450 1rem/1.45 var(--sp-text); color: var(--sp-ink); }
.sp-page .sp-honest { margin: .9rem 0 0; font-size: .86rem; line-height: 1.45; color: var(--sp-muted); }

/* The rule beside the count: one sentence, the current dial setting's clause in ink */
.sp-page .sp-rule-note { margin: 0; padding-top: .8rem; border-top: 1px solid var(--sp-rule); font: 400 .78rem/1.5 var(--sp-mono); color: var(--sp-muted); }
.sp-rule-note span[data-d] { transition: color .2s, background-color .2s; }
.sp-rule-note span.is-on { color: var(--sp-ink); font-weight: 700; background: var(--sp-panel); box-shadow: 0 0 0 2px var(--sp-panel); }

/* Controls */
.sp-page .sp-prompt { margin: 0 0 1rem; font-size: .95rem; line-height: 1.45; color: var(--sp-ink); }
.sp-block { padding: 1.05rem 0 1.15rem; border-top: 1px solid var(--sp-rule); }
.sp-block-dial { border-top: 1.5px solid var(--sp-ink); }
.sp-block[hidden] { display: none; }
.sp-page .sp-block .sp-k { margin-bottom: .75rem; }
.sp-dial { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .4rem; margin: 0; padding: 1.05rem 0 1.15rem; border-width: 1.5px 0 0; min-width: 0; }
.sp-dial legend { float: left; grid-column: 1 / -1; width: 100%; padding: 0; }
.sp-dial-opt { position: relative; display: block; }
.sp-dial-opt input { position: absolute; inset: 0; opacity: 0; margin: 0; cursor: pointer; }
.sp-dial-face {
  display: grid; align-content: start; gap: .3rem; min-height: 5.6rem; padding: .55rem .6rem .6rem; border: 1px solid var(--sp-rule);
  color: var(--sp-ink); pointer-events: none;
}
.sp-dial-n { font: 860 2.4rem/.86 var(--sp-display); letter-spacing: -.05em; font-variant-numeric: tabular-nums; }
.sp-dial-h { font: 400 .72rem/1.3 var(--sp-mono); color: var(--sp-muted); }
.sp-dial-opt:hover .sp-dial-face { border-color: var(--sp-ink); }
.sp-dial-opt input:checked + .sp-dial-face { border-color: var(--sp-ink); background: var(--sp-ink); color: var(--sp-paper); }
.sp-dial-opt input:checked + .sp-dial-face .sp-dial-h { color: var(--sp-paper); }
.sp-dial-opt input:focus-visible + .sp-dial-face { outline: 3px solid var(--sp-ink); outline-offset: 3px; }
.sp-row { display: flex; flex-wrap: wrap; align-items: center; gap: .5rem; }
.sp-btn {
  min-height: 44px; padding: .55rem .95rem; border: 1px solid var(--sp-ink); background: transparent; color: var(--sp-ink); cursor: pointer;
  font: 600 .9rem/1.2 var(--sp-text); text-align: left;
}
.sp-btn:hover { background: var(--sp-panel); }
.sp-btn:disabled { opacity: .45; cursor: default; }
.sp-btn-go { background: var(--sp-ink); color: var(--sp-paper); }
.sp-btn-go:hover { background: transparent; color: var(--sp-ink); }
.sp-btn-lift { background: var(--sp-yellow); color: #1d1d1b; border-color: #1d1d1b; }
.sp-btn-lift:hover { background: var(--sp-yellow); box-shadow: inset 0 0 0 1px #1d1d1b; }
.sp-btn-quiet { border-color: var(--sp-rule); }
.sp-btn[hidden] { display: none; }
.sp-range { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: center; gap: .9rem; }
.sp-range input[type=range] { width: 100%; min-height: 44px; margin: 0; accent-color: #1d1d1b; background: transparent; cursor: pointer; }
.sp-range input[type=range]::-webkit-slider-runnable-track { height: 6px; background: var(--sp-yellow); border: 1px solid var(--sp-ink); }
.sp-range input[type=range]::-webkit-slider-thumb { -webkit-appearance: none; appearance: none; width: 20px; height: 20px; margin-top: -8px; border: 2px solid var(--sp-ink); background: var(--sp-paper); border-radius: 0; }
.sp-range input[type=range]::-moz-range-track { height: 6px; background: var(--sp-yellow); border: 1px solid var(--sp-ink); }
.sp-range input[type=range]::-moz-range-thumb { width: 18px; height: 18px; border: 2px solid var(--sp-ink); background: var(--sp-paper); border-radius: 0; }
.sp-range input[type=range] { -webkit-appearance: none; appearance: none; }
.sp-range-v { min-width: 2.6rem; font: 700 .8rem/1 var(--sp-mono); color: var(--sp-ink); text-align: right; }
.sp-page .sp-help { margin: .6rem 0 0; font: 400 .74rem/1.4 var(--sp-mono); color: var(--sp-muted); }

/* ---------- Sections ---------- */
.sp-section { padding: 4rem 0; border-top: 1px solid var(--sp-rule); scroll-margin-top: 70px; }
.sp-section-grid { display: grid; grid-template-columns: minmax(0, .78fr) minmax(0, 1.22fr); gap: 1.5rem 4rem; align-items: start; }
.sp-section-head { position: sticky; top: 84px; }
.sp-copy { max-width: 44rem; min-width: 0; }
.sp-copy > :last-child { margin-bottom: 0; }
.sp-copy blockquote { margin: 1.6rem 0; padding: .1rem 0 .1rem 1.3rem; border-left: 3px solid var(--sp-ink); font: 450 1.12rem/1.45 var(--sp-text); color: var(--sp-ink); }
.sp-copy blockquote p { margin: 0 0 .5rem; }
.sp-copy blockquote cite { display: block; margin-top: .5rem; font: 700 .64rem/1.5 var(--sp-mono); font-style: normal; letter-spacing: .1em; text-transform: uppercase; color: var(--sp-muted); }
.sp-copy ul, .sp-copy ol { margin: 0 0 1.1rem; padding-left: 1.3rem; }
.sp-copy li { margin: 0 0 .45rem; }

/* Pictures: historical plates */
.sp-plate { margin: 2rem 0 0; }
.sp-plate img { display: block; width: 100%; height: auto; border: 1px solid var(--sp-rule); background: #efe9dc; }
.sp-plate figcaption, .sp-fig figcaption { margin-top: .7rem; font: 700 .64rem/1.5 var(--sp-mono); letter-spacing: .1em; text-transform: uppercase; color: var(--sp-muted); }
.sp-plate figcaption .sp-nocase { text-transform: none; } /* quaternion units are lower case: ij = k */
.sp-plate-tall img { max-width: 24rem; }
.sp-plate-mid img { max-width: 32rem; }
.sp-pair { display: grid; grid-template-columns: repeat(2, minmax(0, 16rem)); gap: 1.6rem; align-items: start; margin-top: 2rem; }
.sp-pair > figure { margin: 0; }
.sp-fig { margin: 2rem 0 0; }
.sp-svg { display: block; width: 100%; height: auto; overflow: visible; }

/* THE ANSWER: three starting points, one worked step, the result */
.sp-answer { padding: 2.8rem 0 3rem; border-top: 1.5px solid var(--sp-ink); }
.sp-page .sp-answer-k { margin: 0 0 1.4rem; max-width: none; font: 700 .72rem/1.3 var(--sp-mono); letter-spacing: .14em; text-transform: uppercase; color: var(--sp-ink); }
.sp-answer-list { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 0; margin: 0; padding: 0; list-style: none; counter-reset: ans; }
.sp-answer-list li { position: relative; display: grid; align-content: start; gap: .7rem; padding: .9rem 1.4rem 0 0; border-top: 1.5px solid var(--sp-ink); counter-increment: ans; }
.sp-answer-list li + li { padding-left: 1.2rem; border-left: 1px solid var(--sp-rule); }
.sp-answer-list li::before { content: counter(ans); position: absolute; top: -.62rem; left: 0; padding-right: .4rem; background: var(--sp-paper); font: 700 .7rem/1.2 var(--sp-mono); color: var(--sp-muted); }
.sp-answer-list li + li::before { left: 1.2rem; }
.sp-tag { justify-self: start; padding: .22rem .45rem; border: 1px solid var(--sp-ink); font: 700 .6rem/1.2 var(--sp-mono); letter-spacing: .12em; color: var(--sp-ink); }
.sp-tag-worked { border-color: var(--sp-green); color: var(--sp-green); }
.sp-tag-result { background: var(--sp-ink); color: var(--sp-paper); }
.sp-answer-line { font: 500 1.02rem/1.4 var(--sp-text); color: var(--sp-ink); letter-spacing: -.005em; }
.sp-answer-result { font: 780 1.5rem/1.1 var(--sp-display); letter-spacing: -.02em; }
.sp-page .sp-answer-note { margin: 1.6rem 0 0; font-size: .92rem; color: var(--sp-muted); }

/* The bridge between the two reasons */
.sp-bridge { padding: 3.4rem 0; border-top: 1.5px solid var(--sp-ink); background: var(--sp-panel); }
.sp-page .sp-bridge h2.sp-eyebrow { margin: .4rem 0 0; color: var(--sp-ink); }
.sp-page .sp-bridge-text { margin: 0; font: 600 clamp(1.3rem, 2vw, 1.7rem)/1.3 var(--sp-display); letter-spacing: -.015em; color: var(--sp-ink); }

/* S08: a loop in 2, 3 and 4 directions, drawn small */
.sp-trio-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; padding-top: 1rem; border-top: 1px solid var(--sp-rule); }
.sp-page .sp-trio-cell p { margin: .4rem 0 0; font: 400 .74rem/1.3 var(--sp-mono); color: var(--sp-muted); }
.sp-trio-n { margin-right: .35rem; font: 860 1.3rem/1 var(--sp-display); letter-spacing: -.04em; color: var(--sp-ink); }
.sp-trio .ink { stroke: var(--sp-ink); stroke-width: 2.6; fill: none; stroke-linecap: round; }
.sp-trio .mag { stroke: var(--sp-magenta); stroke-width: 2.6; fill: none; stroke-linecap: round; }
.sp-trio .mag-dash { stroke: var(--sp-magenta); stroke-width: 2.6; fill: none; stroke-dasharray: 6 4.5; }
.sp-trio .yel { stroke: var(--sp-yellow); stroke-width: 7; fill: none; stroke-linecap: round; }
.sp-trio .film { fill: var(--sp-film); stroke: none; }
.sp-trio .halo { stroke: var(--sp-paper); stroke-width: 9; fill: none; }
.sp-trio .hair { stroke: var(--sp-hair); stroke-width: 1.1; fill: none; }
.sp-trio .hair-dash { stroke: var(--sp-hair); stroke-width: 1.1; fill: none; stroke-dasharray: 3 4; }
.sp-trio .dot { fill: var(--sp-magenta); }
.sp-trio .poke { fill: var(--sp-cyan); stroke: var(--sp-paper); stroke-width: 2; }

/* Sources */
.sp-sources .sp-section-head h2.sp-eyebrow { margin: 0; color: var(--sp-ink); }
.sp-refs a { color: var(--sp-body); }
.sp-refs a:hover { color: var(--sp-ink); }
.sp-doi { font: 400 .78rem/1.4 var(--sp-mono); color: var(--sp-muted); white-space: nowrap; }
@media (max-width: 560px) { .sp-doi { white-space: normal; overflow-wrap: anywhere; } }
.sp-refs li.sp-ref-rs a { color: var(--sp-ink); font-weight: 600; }
.sp-page .sp-texts { margin: 1.4rem 0 0; font-size: .86rem; line-height: 1.6; color: var(--sp-muted); }

/* A printed passage, set wide */
.sp-plate-text img { background: #f6f1e4; }

/* The question through time: an index of the sections, oldest first, each a link */
.sp-time { margin: 0; padding: 2.6rem 0 2.4rem; border-top: 1px solid var(--sp-rule); }
.sp-time ol { display: grid; grid-auto-flow: column; grid-auto-columns: minmax(9.5rem, 1fr); gap: 0; margin: 0; padding: 0; list-style: none; overflow-x: auto; overscroll-behavior-x: contain; scrollbar-width: thin; }
.sp-time li { min-width: 0; border-top: 1.5px solid var(--sp-ink); }
.sp-time a { display: grid; align-content: start; gap: .45rem; height: 100%; padding: .7rem 1rem 1rem 0; text-decoration: none; color: var(--sp-ink); }
.sp-time a::before { content: ""; display: block; width: .55rem; height: .55rem; margin-top: -1.06rem; background: var(--sp-ink); }
.sp-time .y { font: 860 1.35rem/1 var(--sp-display); letter-spacing: -.03em; font-variant-numeric: tabular-nums lining-nums; }
.sp-time .t { font: 400 .74rem/1.4 var(--sp-mono); color: var(--sp-muted); }
.sp-time a:hover .t { color: var(--sp-ink); text-decoration: underline; text-underline-offset: .2em; }
.sp-time li.is-rs a::before { background: var(--sp-magenta); }

/* Quotations from the sources */
.sp-copy blockquote.sp-q { margin: 1.8rem 0; padding: 0 0 0 1.3rem; border-left: 3px solid var(--sp-ink); }
.sp-copy blockquote.sp-q p { font: 500 clamp(1.15rem, 1.6vw, 1.32rem)/1.38 var(--sp-text); letter-spacing: -.01em; color: var(--sp-ink); }
.sp-copy blockquote.sp-q .sp-orig { font: 400 .86rem/1.5 var(--sp-text); font-style: italic; color: var(--sp-muted); }

/* The film */
.sp-film-frame { aspect-ratio: 16 / 9; margin-top: 1.5rem; background: var(--sp-panel); border: 1px solid var(--sp-rule); }
.sp-film-frame video { display: block; width: 100%; height: 100%; }

/* The rule on a sticky note: a small table */
.sp-holds { width: 100%; margin: 1.6rem 0 0; border-collapse: collapse; font: 400 .95rem/1.35 var(--sp-text); }
.sp-holds caption { caption-side: top; text-align: left; padding-bottom: .6rem; font: 700 .7rem/1.3 var(--sp-mono); letter-spacing: .14em; text-transform: uppercase; color: var(--sp-soft); }
.sp-holds th, .sp-holds td { padding: .7rem .6rem .7rem 0; border-top: 1px solid var(--sp-rule); text-align: left; vertical-align: top; }
.sp-holds thead th { border-top: 1.5px solid var(--sp-ink); font: 700 .64rem/1.3 var(--sp-mono); letter-spacing: .12em; text-transform: uppercase; color: var(--sp-muted); }
.sp-holds td.sp-eq { font: 700 .95rem/1.35 var(--sp-mono); color: var(--sp-ink); white-space: nowrap; }
.sp-holds tr.is-here td, .sp-holds tr.is-here th { background: var(--sp-panel); }
.sp-holds tr.is-here th { box-shadow: inset 3px 0 0 var(--sp-ink); padding-left: .7rem; }
.sp-holds tbody th { font: 860 1.5rem/1 var(--sp-display); letter-spacing: -.04em; color: var(--sp-ink); padding-left: .7rem; }

/* ---------- THE CUBE ---------- */
.sp-cube { margin: 2.2rem 0 0; padding: 1.4rem 0 0; border-top: 1.5px solid var(--sp-ink); }
.sp-cube-grid { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr); gap: 1.6rem 2rem; align-items: start; }
.sp-cube-svg { display: block; width: 100%; height: auto; overflow: visible; touch-action: manipulation; }
.sp-cube-svg:focus { outline: none; }
.sp-cube-svg .road { stroke-width: 2.2; fill: none; stroke-linecap: square; }
.sp-cube-svg .road.trunk { stroke: var(--sp-ink); }
.sp-cube-svg .gap { stroke: var(--sp-paper); stroke-width: 4.5; }
.sp-cube-svg .road.left { stroke: var(--sp-cyan); stroke-width: 2.6; }
.sp-cube-svg .arrow { fill: var(--sp-cyan); }
.sp-cube-svg .tag rect { fill: var(--sp-paper); stroke: var(--sp-cyan); stroke-width: 1.5; }
.sp-cube-svg .tag text { font: 700 12px var(--sp-mono); fill: var(--sp-cyan-text); text-anchor: middle; dominant-baseline: central; }
.sp-cube-svg .trail { stroke: var(--sp-magenta); stroke-width: 12; fill: none; stroke-linecap: round; stroke-linejoin: round; opacity: .3; }
.sp-cube-svg .corner { cursor: pointer; }
.sp-cube-svg .corner circle.c { fill: var(--sp-paper); stroke: var(--sp-ink); stroke-width: 1.6; }
.sp-cube-svg .corner.is-visited circle.c { fill: var(--sp-ink); }
.sp-cube-svg .corner.is-next circle.c { stroke: var(--sp-magenta); stroke-width: 2.4; }
.sp-cube-svg .corner circle.hit { fill: transparent; stroke: none; }
.sp-cube-svg .corner text { font: 700 12.5px var(--sp-mono); fill: var(--sp-ink); letter-spacing: .02em; }
.sp-cube-svg .here { fill: var(--sp-magenta); stroke: var(--sp-paper); stroke-width: 2; transition: transform .22s cubic-bezier(.65, 0, .35, 1); }
.sp-cube-svg .start-ring { fill: none; stroke: var(--sp-ink); stroke-width: 1.2; stroke-dasharray: 2 3; }
.sp-cube-svg text.small { font: 700 10px var(--sp-mono); fill: var(--sp-muted); letter-spacing: .08em; }
.sp-cube-tools { display: grid; gap: .9rem; }
.sp-cube-tools .sp-row .sp-btn { flex: 1 1 auto; }
.sp-cube-tools .sp-row .sp-btn-quiet { flex: 0 0 auto; }
.sp-btn-lap { border-color: var(--sp-magenta); }
.sp-btn-lap:hover { background: color-mix(in srgb, var(--sp-magenta) 9%, transparent); }
.sp-cube-reads { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .6rem 1rem; margin: 1.4rem 0 0; padding-top: .9rem; border-top: 1px solid var(--sp-rule); }
.sp-page .sp-cube-reads p { margin: 0; }
.sp-page .sp-cube-reads .sp-k { display: block; margin: 0 0 .35rem; font-size: .62rem; }
.sp-read-v { font: 860 1.9rem/1 var(--sp-display); letter-spacing: -.04em; color: var(--sp-ink); font-variant-numeric: tabular-nums; }
.sp-panels { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr) minmax(0, 13rem); gap: 1.2rem 1.6rem; margin-top: 1.4rem; padding-top: 1rem; border-top: 1px solid var(--sp-rule); align-items: start; }
.sp-page .sp-panels .sp-k { margin: 0 0 .25rem; color: var(--sp-ink); }
.sp-page .sp-panels .sp-sub { margin: 0 0 .7rem; }
.sp-tally { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: .3rem; margin: 0; padding: 0; list-style: none; }
.sp-tally li { display: grid; gap: .2rem; padding: .45rem .3rem .5rem; border: 1px solid var(--sp-rule); text-align: center; }
.sp-tally .r { font: 700 .62rem/1 var(--sp-mono); color: var(--sp-cyan-text); letter-spacing: .06em; }
.sp-tally .t { font: 860 1.35rem/1 var(--sp-display); letter-spacing: -.03em; color: var(--sp-ink); font-variant-numeric: tabular-nums; }
.sp-tally li.is-zero .t { color: var(--sp-muted); }
.sp-tally li.is-bump { border-color: var(--sp-cyan); }
.sp-record { display: flex; flex-wrap: wrap; gap: .3rem; min-height: 2.2rem; margin: 0; padding: 0; list-style: none; counter-reset: rec; }
.sp-record li { display: inline-flex; align-items: center; gap: .35rem; padding: .3rem .5rem; border: 1px solid var(--sp-ink); font: 700 .74rem/1.2 var(--sp-mono); color: var(--sp-ink); white-space: nowrap; }
.sp-record li .n { display: inline-grid; place-items: center; min-width: 1.15rem; height: 1.15rem; border: 1.5px solid var(--sp-cyan); color: var(--sp-cyan-text); font-size: .68rem; }
.sp-record li.is-gone { opacity: .35; text-decoration: line-through; border-style: dashed; }
.sp-record li.is-empty { border-style: dashed; border-color: var(--sp-rule); color: var(--sp-muted); font-weight: 400; }
.sp-order-v { display: block; margin: .1rem 0 .4rem; font: 860 2.6rem/.9 var(--sp-display); letter-spacing: -.05em; color: var(--sp-magenta-text); font-variant-numeric: tabular-nums; }
.sp-order-v[data-off] { color: var(--sp-muted); }
.sp-dot-svg { display: block; width: 100%; max-width: 13rem; height: auto; overflow: visible; }
.sp-dot-svg .grid { stroke: var(--sp-rule); stroke-width: 1; }
.sp-dot-svg .axis { stroke: var(--sp-hair); stroke-width: 1.2; }
.sp-dot-svg .walk { stroke: var(--sp-magenta); stroke-width: 2.4; fill: none; stroke-linejoin: round; }
.sp-dot-svg .area { fill: color-mix(in srgb, var(--sp-magenta) 14%, transparent); stroke: none; }
.sp-dot-svg .dot { fill: var(--sp-magenta); stroke: var(--sp-paper); stroke-width: 1.5; }
.sp-dot-svg .origin { fill: var(--sp-ink); }
.sp-dot-svg text { font: 700 9.5px var(--sp-mono); fill: var(--sp-muted); letter-spacing: .06em; }
.sp-page .sp-cube-caption { min-height: 3em; margin: 1.2rem 0 0; padding-top: .8rem; border-top: 1.5px solid var(--sp-ink); font: 450 1rem/1.45 var(--sp-text); color: var(--sp-ink); }

/* Sources */
.sp-cite { padding: 1.6rem 1.7rem 1.5rem; border: 1.5px solid var(--sp-ink); background: var(--sp-panel); }
.sp-page .sp-cite-tag { margin: 0 0 1rem; font: 700 .7rem/1.4 var(--sp-mono); letter-spacing: .12em; text-transform: uppercase; color: var(--sp-ink); }
.sp-page .sp-cite-body { font-size: 1rem; line-height: 1.55; color: var(--sp-body); }
.sp-page .sp-cite-links { margin: 1.2rem 0 0; }
.sp-cite-primary { display: inline-flex; align-items: center; min-height: 44px; padding: .55rem 1rem; border: 1px solid var(--sp-ink); background: var(--sp-ink); color: var(--sp-paper) !important; text-decoration: none !important; font-weight: 600; }
.sp-cite-primary:hover { background: transparent; color: var(--sp-ink) !important; }
.sp-refs { margin: 1.6rem 0 0; padding: 0; list-style: none; border-top: 1px solid var(--sp-rule); font-size: .92rem; line-height: 1.5; }
.sp-refs li { padding: .7rem 0; border-bottom: 1px solid var(--sp-rule); }
.sp-more { display: grid; gap: .1rem; margin: 0; padding: 0; list-style: none; border-top: 1.5px solid var(--sp-ink); }
.sp-more li { border-bottom: 1px solid var(--sp-rule); }
.sp-more a { display: flex; align-items: center; justify-content: space-between; gap: 1rem; min-height: 48px; padding: .6rem 0; text-decoration: none; font-weight: 500; }
.sp-more a::after { content: "→"; font-family: var(--sp-mono); color: var(--sp-muted); }
.sp-more a:hover { text-decoration: underline; }

/* Closing */
.sp-closing { padding: 4.5rem 0 3rem; border-top: 1.5px solid var(--sp-ink); }
.sp-page .sp-closing-line { margin: 0; max-width: 24ch; font: 820 clamp(2rem, 4vw, 3.4rem)/.98 var(--sp-display); letter-spacing: -.035em; color: var(--sp-ink); }

/* ---------- Responsive ---------- */
@media (max-width: 1080px) {
  .sp-hero-text { max-width: 40rem; }
  .sp-title { max-width: 15ch; }
  .sp-section-head { position: static; }
  .sp-panels { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .sp-panels .sp-panel-order { grid-column: 1 / -1; display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 12rem); gap: 0 1.4rem; }
}
/* Tablets: the canvas stays in view (sticky) beside the readout and controls. */
@media (min-width: 761px) and (max-width: 1080px) {
  .sp-hero-grid { grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr); grid-template-areas: none; grid-template-rows: none; column-gap: 1.8rem; position: relative; }
  .sp-stage, .sp-panes, .sp-panel { display: contents; }
  .sp-hero-text { grid-area: auto; grid-column: 1 / -1; grid-row: 1; }
  .sp-pane-c { grid-column: 1; grid-row: 2 / span 10; position: sticky; top: 84px; align-self: start; }
  .sp-pane-q, .sp-caption, .sp-honest, .sp-prompt, .sp-block { grid-column: 2; }
  .sp-pane-q { order: 1; padding-top: 1.9rem; } .sp-caption { order: 2; } .sp-prompt { order: 3; margin-top: 1rem !important; }
  .sp-block-dial { order: 4; } .sp-block-act { order: 5; } .sp-block-w { order: 6; } .sp-honest { order: 7; }
  .sp-num { font-size: 4.2rem; }
}
@media (max-width: 1080px) {
  .sp-answer-list { grid-template-columns: minmax(0, 1fr); }
  .sp-answer-list li, .sp-answer-list li + li { grid-template-columns: 9.5rem minmax(0, 1fr); align-items: baseline; gap: 1rem; padding: .85rem 0 .85rem 1.6rem; border-left: 0; border-top: 1px solid var(--sp-rule); }
  .sp-answer-list li:first-child { border-top: 1.5px solid var(--sp-ink); }
  .sp-answer-list li::before, .sp-answer-list li + li::before { top: .95rem; left: 0; padding: 0; background: none; }
}
@media (max-width: 860px) {
  .sp-section-grid { grid-template-columns: minmax(0, 1fr); gap: 1.2rem; }
  .sp-pair { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; }
  .sp-cube-grid { grid-template-columns: minmax(0, 1fr); }
  .sp-cube-svg { max-width: 30rem; }
}
/* Phones: the canvas, what happened, the dial and the moves right under it, then the count. */
@media (max-width: 760px) {
  body.sp-body[data-rpi-page] { --sp-gutter: 1rem; }
  .sp-hero { padding-top: 2rem; }
  .sp-hero-grid { display: flex; flex-direction: column; align-items: stretch; }
  .sp-stage, .sp-panes, .sp-panel { display: contents; }
  .sp-hero-text { order: 1; padding-bottom: 1.4rem; }
  .sp-pane-c { order: 2; }
  .sp-pane-q { order: 3; padding-top: .9rem; display: grid; grid-template-columns: auto minmax(0, 1fr); column-gap: 1rem; align-items: end; }
  .sp-pane-q > .sp-k { grid-column: 1 / -1; }
  .sp-pane-q .sp-count { grid-row: 2 / span 2; }
  .sp-pane-q .sp-sub { margin: 0 0 .35rem; }
  .sp-pane-q .sp-state { margin: 0; justify-self: start; }
  .sp-pane-q .sp-rule-note { grid-column: 1 / -1; margin-top: .9rem; }
  .sp-num { font-size: 4.4rem; }
  .sp-caption { order: 4; }
  .sp-prompt { order: 5; margin-top: 1rem !important; }
  .sp-block-dial { order: 6; } .sp-block-act { order: 7; } .sp-block-w { order: 8; }
  .sp-honest { order: 9; }
  .sp-canvas-wrap { aspect-ratio: 1 / 1; }
  .sp-section { padding: 2.8rem 0; }
  .sp-cite { padding: 1.2rem 1.1rem; }
  .sp-panels { grid-template-columns: minmax(0, 1fr); }
  .sp-panels .sp-panel-order { grid-template-columns: minmax(0, 1fr) minmax(0, 10rem); }
  .sp-cube-reads { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (max-width: 560px) {
  .sp-answer-list li, .sp-answer-list li + li { grid-template-columns: minmax(0, 1fr); gap: .45rem; }
  .sp-trio-grid { gap: .5rem; }
  .sp-page .sp-trio-cell p { font-size: .66rem; }
}
@media (max-width: 400px) {
  .sp-dial-face { min-height: 5rem; padding: .5rem .45rem; }
  .sp-dial-n { font-size: 2rem; }
  .sp-tally .t { font-size: 1.1rem; }
}
@media (prefers-reduced-motion: reduce) {
  .sp-page *, .sp-cube-svg * { transition: none !important; animation: none !important; }
}
@media print {
  body.sp-body[data-rpi-page] { background: #fff; color: #000; }
  .sp-stage, .sp-panel, .sp-film, .sp-cube-tools { display: none; }
  .sp-hero-grid { display: block; }
  .sp-section { break-inside: avoid; padding: 1.5rem 0; }
  .sp-section-head { position: static; }
}