/* The story page (research/integer-multiplication/story). Generated by story-src/build.py: edit there.
   f0.css tokens only, plus --mark-im for the series (validated: light #2a5fb0, dark #4f90e3). */
:root { --mark-im: #2a5fb0; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) { --mark-im: #4f90e3; } }
:root[data-theme="dark"] { --mark-im: #4f90e3; }

.st-hero .wrap { align-items: center; }
.st-hero .dek a { white-space: nowrap; }
.st-hero .ph-text { min-width: 0; }
.st-hero .h1 { max-width: 16ch; }
.st-hero .dek { max-width: 54ch; }
.st-hero .dek strong { color: var(--ink); font-weight: 600; }
.st-spark { align-self: center; }
.st-sp-stage { position: relative; margin-top: 12px; background: var(--bg-1); border: 1px solid var(--line); padding: 12px 12px 26px; }
.st-sp { display: block; width: 100%; height: auto; overflow: visible; }
.st-sp .grid { stroke: var(--grid); stroke-width: 1; vector-effect: non-scaling-stroke; }
.st-sp .axis { stroke: var(--line-ui); stroke-width: 1; fill: none; vector-effect: non-scaling-stroke; }
.st-sp .series { fill: none; stroke: var(--mark-im); stroke-width: 2; stroke-linejoin: round; vector-effect: non-scaling-stroke; }
.st-sp .ext { fill: none; stroke: var(--mark-im); stroke-width: 1.6; stroke-dasharray: 4 3; vector-effect: non-scaling-stroke; }
.st-sp .dot { fill: var(--mark-im); stroke: var(--bg-1); stroke-width: 1.5; vector-effect: non-scaling-stroke; }
.st-sp .now { fill: var(--st-verified); stroke: var(--bg-1); stroke-width: 2; vector-effect: non-scaling-stroke; }
.st-sp-axis { position: absolute; left: 12px; right: 12px; bottom: 6px; height: 16px; }
.st-sp-axis span { position: absolute; transform: translateX(-50%); font: 400 11.5px/16px var(--f-mono); color: var(--ink-3); white-space: nowrap; }
.st-sp-axis span:first-child { transform: none; }
.st-sp-axis span:last-child { transform: translateX(-70%); }
.st-sp-facts { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1px; background: var(--line); border: 1px solid var(--line); margin: 12px 0 0; }
.st-sp-facts > div { background: var(--bg-2); padding: 9px 10px; min-width: 0; }
.st-sp-facts dt { font: 500 11px/1.35 var(--f-mono); letter-spacing: .08em; text-transform: uppercase; color: var(--ink-3); }
.st-sp-facts dd { margin: 4px 0 0; font: 500 15px/1.3 var(--f-mono); color: var(--ink); overflow-wrap: anywhere; }
.st-sp-facts dd small { font: 400 12px var(--f-mono); color: var(--ink-2); margin-left: 4px; }
@media (max-width: 420px) { .st-sp-facts { grid-template-columns: minmax(0, 1fr); } }
.st-spark .fig-foot { display: flex; flex-wrap: wrap; gap: 8px 14px; align-items: center; }
.st-open { margin: var(--s-6) 0 0; }
.st-open-k { font: 500 11px/1.3 var(--f-mono); letter-spacing: .14em; text-transform: uppercase; color: var(--ink-3); margin-bottom: 8px; }
.st-open p + p { font: 400 var(--fs-lede)/1.5 var(--f-serif); color: var(--ink); max-width: 60ch; }
.st-open strong { font-weight: 600; }

/* "Break it": the exact checker */
.st-check { margin-top: var(--s-6); }
.st-ck { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr); gap: 14px 22px; margin-top: 14px; padding: 14px; background: var(--bg-1); border: 1px solid var(--line); }
@media (max-width: 720px) { .st-ck { grid-template-columns: minmax(0, 1fr); } }
.st-ck-k { display: block; font: 500 11px/1.35 var(--f-mono); letter-spacing: .1em; text-transform: uppercase; color: var(--ink-3); }
.st-ck-sub { margin-top: 14px; text-transform: none; letter-spacing: .02em; font-size: 12px; }
.st-ck-in { display: block; width: 100%; margin-top: 6px; padding: 8px 10px; min-height: 44px; font: 500 clamp(15px, 1vw + 11px, 19px)/1.3 var(--f-mono); color: var(--ink); background: var(--bg-2); border: 1px solid var(--line-ui); border-radius: var(--r-btn); }
.st-ck-grid { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 8px; margin-top: 8px; }
@media (max-width: 520px) { .st-ck-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.st-ck-n { display: grid; gap: 3px; font: 400 12px/1.3 var(--f-mono); color: var(--ink-2); min-width: 0; }
.st-ck-n input { width: 100%; min-width: 0; min-height: 40px; padding: 6px 8px; font: 500 14px var(--f-mono); color: var(--ink); background: var(--bg-2); border: 1px solid var(--line-ui); border-radius: var(--r-btn); }
.st-ck-in:focus-visible, .st-ck-n input:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
.st-ck-n input.changed, .st-ck-in.changed { border-color: var(--hair); box-shadow: inset 0 0 0 1px var(--hair); }
.st-ck-out { display: grid; align-content: start; gap: 8px; padding: 12px 14px; background: var(--bg-2); border: 1px solid var(--line); border-left: 3px solid var(--st-verified); }
.st-ck-out.no { border-left-color: var(--st-contested); }
.st-ck-out.unsure { border-left-color: var(--st-preprint); }
.st-ck-verdict { font: 600 var(--fs-ui)/1.35 var(--f-sans); color: var(--ink); }
.st-ck-verdict::before { content: "✓ "; color: var(--st-verified); }
.st-ck-out.no .st-ck-verdict::before { content: "✕ "; color: var(--st-contested); }
.st-ck-out.unsure .st-ck-verdict::before { content: "? "; color: var(--ink-3); }
.st-ck-bill { font: 400 var(--fs-sm)/1.5 var(--f-sans); color: var(--ink-2); }
.st-ck-bill span { font: 500 15px var(--f-mono); color: var(--ink); white-space: nowrap; }
.st-ck-time { font: 400 12.5px/1.45 var(--f-mono); color: var(--ink-3); }
.st-check .fig-ctrl { margin-top: 12px; }
html:not(.js) .st-ck input { pointer-events: none; }

.st-sec { padding-block: clamp(40px, 6vw, 80px); }
.st-sec .sec-head { margin-bottom: var(--s-4); }
.st-h2 { font: 600 clamp(24px, 1.6vw + 16px, 36px)/1.12 var(--f-sans); letter-spacing: -.025em; max-width: 24ch; margin-bottom: var(--s-5); }
.st-read .prose { max-width: none; }
.st-read .prose em { font-style: italic; }
.st-read > .fig, .st-read > .statrow, .st-read > .callout { margin-top: var(--s-6); }
.st-read > .callout { max-width: none; }

.chart { width: 100%; height: auto; display: block; overflow: visible; margin-top: 10px; }
.chart .grid { stroke: var(--grid); stroke-width: 1; }
.chart .axis { stroke: var(--line-ui); stroke-width: 1; }
.chart .series { fill: none; stroke: var(--mark-im); stroke-width: 2; stroke-linejoin: round; }
.chart .dot { fill: var(--mark-im); stroke: var(--bg-1); stroke-width: 2; cursor: default; }
.chart .dot:focus { outline: none; }
.chart .dot:focus-visible, .chart .dot:hover { stroke: var(--ink); }
.chart .bar { fill: var(--mark-im); }
.chart .bar:focus { outline: none; }
.chart .bar:focus-visible, .chart .bar:hover { stroke: var(--ink); stroke-width: 1.5; }
.chart .tick { fill: var(--ink-3); font: 11px var(--f-mono); font-variant-numeric: tabular-nums; }
.chart .tick-y { text-anchor: end; } .chart .tick-x { text-anchor: middle; }
.chart .barval { fill: var(--ink-2); font: 600 11px var(--f-mono); text-anchor: middle; }
.chart .lastlabel { fill: var(--ink); font: 600 13px var(--f-mono); text-anchor: end; }
.st-pair { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; margin-top: 12px; }
@media (max-width: 640px) { .st-pair { grid-template-columns: minmax(0, 1fr); } }
.st-pair figcaption, .st-cap { font: 400 12.5px/1.5 var(--f-sans); color: var(--ink-3); margin-top: 6px; }
.st-stage { background: var(--bg-1); border: 1px solid var(--line); padding: 12px 12px 8px; margin-top: 14px; }
.st-gf { margin-top: var(--s-5); max-width: 560px; }
.st-gf td.n, .st-gf th.n { text-align: right; font-family: var(--f-mono); font-variant-numeric: tabular-nums; }
.st-colophon { margin-top: var(--s-7); padding-top: var(--s-4); border-top: 1px dashed var(--line-ui); font: 400 var(--fs-xs)/1.6 var(--f-sans); color: var(--ink-3); }
.st-fix { list-style: none; margin: var(--s-5) 0 0; padding: 0; display: grid; gap: 1px; background: var(--line); border: 1px solid var(--line); }
.st-fix li { background: var(--bg-2); padding: 14px 16px; display: grid; gap: 6px; }
.st-fix .q { font: italic 400 var(--fs-sm)/1.55 var(--f-serif); color: var(--ink); }
.st-fix .q::before { content: "The essay says: "; font: 500 11px/1.4 var(--f-mono); font-style: normal; letter-spacing: .1em; text-transform: uppercase; color: var(--st-contested); margin-right: 4px; }
.st-fix .a { font: 400 var(--fs-sm)/1.55 var(--f-sans); color: var(--ink-2); }
.st-fix .a b { color: var(--ink); font-weight: 600; }
.st-end { padding: 0 0 var(--sec-pad); }
.st-narrow { display: none; }
@media (max-width: 560px) { .st-wide { display: none; } .st-narrow { display: block; } }
.st-read .statrow { grid-template-columns: repeat(4, minmax(0, 1fr)); }
@media (max-width: 560px) { .st-read .statrow { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.chart.small .tick, .chart.small .barval { font-size: 13px; }
.chart.st-line .tick { font-size: 12px; }
.st-end .prevnext { margin-top: 0; }