/* Theoria Math Lab — uses the site tokens from site.css (paper / ink / brick, Archivo + Instrument Sans). */
[data-math], [data-math-ex] { cursor: pointer; }
svg [data-math] { transition: opacity 150ms var(--ease-out); }
svg [data-math]:hover { opacity: .82; }
svg [data-math]:focus { outline: none; }
svg [data-math]:focus-visible { outline: 2px solid var(--brick-500); outline-offset: 3px; }
.ml-live { animation: ml-beat 1.4s ease-in-out infinite; }
@keyframes ml-beat { 50% { opacity: .45; } }

.math-num { font: inherit; color: inherit; background: none; border: 0; padding: 0; border-bottom: 2px dotted var(--brick-400); cursor: pointer; font-variant-numeric: tabular-nums; }
.math-num:hover, .math-num:focus-visible { background: var(--brick-100); outline: none; }
.show-math { display: inline-flex; align-items: center; gap: 8px; margin-top: 12px; font: 600 14px/1 var(--sans); color: var(--brick-700); background: var(--brick-100); border: 1px solid var(--brick-200); border-radius: 0; padding: 10px 14px; min-height: 44px; }
.show-math:hover { background: var(--brick-200); }
.show-math b { font: italic 700 16px/1 var(--display); }
p.n .math-num { font-weight: inherit; }

.ml-tip { position: absolute; z-index: 60; pointer-events: none; transform: translate(-50%, calc(-100% - 10px)); background: var(--ink-900); color: var(--paper); font: 500 13px/1.4 var(--sans); padding: 8px 12px; white-space: nowrap; box-shadow: var(--shadow-3); }
.ml-tip em { display: block; font-style: normal; color: var(--brick-200); font-weight: 600; margin-top: 2px; }

.ml-scrim { position: fixed; inset: 0; z-index: 70; background: rgba(23,25,30,.32); opacity: 0; pointer-events: none; transition: opacity 300ms var(--ease-out); }
body.ml-open .ml-scrim { opacity: 1; pointer-events: auto; }
.ml { position: fixed; z-index: 80; top: 0; right: 0; bottom: 0; width: min(480px, 100%); display: flex; flex-direction: column; background: var(--paper); color: var(--ink-900); border-left: 1px solid var(--ink-200); box-shadow: var(--shadow-3);
  transform: translateX(102%); transition: transform 420ms var(--ease-out); padding-top: env(safe-area-inset-top, 0px); padding-right: env(safe-area-inset-right, 0px); padding-bottom: env(safe-area-inset-bottom, 0px); }
body.ml-open .ml { transform: none; }
@media (min-width: 1440px) {
  body.ml-open .ml-scrim { opacity: 0; pointer-events: none; }
  .article-layout { transition: transform 420ms var(--ease-out); }
  body.ml-open .article-layout { transform: translateX(-200px); }
}
@media (max-width: 760px) {
  .ml { top: auto; left: 0; width: 100%; height: 88%; border-left: 0; border-top: 1px solid var(--ink-200); transform: translateY(102%); padding-left: env(safe-area-inset-left, 0px); }
  body.ml-open .ml { transform: none; }
}
.ml-head { padding: 16px 20px 12px; border-bottom: 1px solid var(--ink-200); display: grid; gap: 12px; }
.ml-top { display: flex; justify-content: space-between; align-items: flex-start; gap: 12px; }
.ml-k { margin: 0; font: 700 12px/1.3 var(--sans); letter-spacing: .12em; text-transform: uppercase; color: var(--brick-500); display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.ml-k .tag { letter-spacing: .04em; }
.ml h2 { font: 700 22px/1.2 var(--display); letter-spacing: -0.02em; margin: 8px 0 0; }
.ml-x { flex: none; width: 44px; height: 44px; border: 1px solid var(--ink-200); background: var(--white); color: var(--ink-900); font: 500 22px/1 var(--sans); cursor: pointer; }
.ml-x:hover { background: var(--ink-100); }
.ml-pick { display: flex; flex-wrap: wrap; gap: 6px; }
.ml-pick button { font: 500 13px/1 var(--sans); padding: 8px 10px; min-height: 36px; border: 1px solid var(--ink-200); background: var(--white); color: var(--ink-600); cursor: pointer; }
.ml-pick button[aria-pressed="true"] { background: var(--ink-900); border-color: var(--ink-900); color: var(--paper); }
.ml-tabs { display: flex; gap: 4px; padding: 0 20px; border-bottom: 1px solid var(--ink-200); }
.ml-tabs button { font: 600 14px/1 var(--sans); color: var(--ink-500); background: none; border: 0; border-bottom: 3px solid transparent; padding: 14px 8px 11px; cursor: pointer; }
.ml-tabs button[aria-selected="true"] { color: var(--ink-900); border-bottom-color: var(--brick-500); }
.ml-body { flex: 1; overflow-y: auto; padding: 20px 20px 32px; font: 400 16px/1.55 var(--sans); }
.ml-answer b { font: 800 48px/1 var(--display); letter-spacing: -0.03em; font-variant-numeric: tabular-nums; }
.ml-idea { color: var(--ink-600); margin: 10px 0 16px; }
.ml-ctrl { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 18px; }
.ml-ghost { background: var(--white); color: var(--ink-900); border: 1px solid var(--ink-200); }
.ml-steps { list-style: none; margin: 0; padding: 0; }
.ml-step { position: relative; padding: 0 0 18px 34px; transition: opacity 300ms; }
.ml-step::before { content: attr(data-n); position: absolute; left: 0; top: 0; width: 22px; height: 22px; background: var(--ink-900); color: var(--paper); font: 700 12px/22px var(--sans); text-align: center; }
.ml-step:not(:last-child)::after { content: ""; position: absolute; left: 10.5px; top: 26px; bottom: 4px; width: 1px; background: var(--ink-200); }
.ml-step.pending { opacity: .18; }
.ml-say { font: 600 14px/1.4 var(--sans); margin-bottom: 8px; }
.ml-eq { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 8px; }
.ml-c { display: inline-grid; padding: 5px 9px; background: var(--white); border: 1px solid var(--ink-200); transition: opacity 300ms, transform 350ms var(--ease-out); }
.ml-c b { font: 700 15px/1.2 var(--sans); font-variant-numeric: tabular-nums; }
.ml-c small { font: 400 11.5px/1.25 var(--sans); color: var(--ink-500); }
.ml-c.ref { border-style: dashed; border-color: var(--ink-400); }
.ml-c.lit { border-color: var(--brick-500); background: var(--brick-100); }
.ml-o { font: 700 17px/1 var(--sans); color: var(--brick-500); }
.ml-r { background: var(--ink-900); border-color: var(--ink-900); }
.ml-r b { color: var(--paper); } .ml-r small { color: var(--ink-300); }
.ml-r.lit { outline: 2px solid var(--brick-500); outline-offset: 2px; }
.pre { opacity: 0; transform: translateY(8px); }
.ml-box { border: 1px solid var(--ink-200); background: var(--white); padding: 14px; margin-top: 6px; }
.ml-box h3 { font: 700 12px/1 var(--sans); letter-spacing: .12em; text-transform: uppercase; color: var(--ink-500); margin: 0 0 10px; }
.ml-calc { display: flex; gap: 8px; align-items: center; }
.ml-calc code { flex: 1; min-width: 0; overflow-x: auto; white-space: nowrap; font: 500 14px/1.4 ui-monospace, Menlo, Consolas, monospace; background: var(--ink-100); padding: 10px; }
.ml-verify { display: flex; gap: 10px; align-items: flex-start; font-size: 14px; line-height: 1.5; color: var(--ink-600); background: var(--ink-100); padding: 12px 14px; margin: 16px 0 0; }
.ml-verify > span:first-child { flex: none; width: 22px; height: 22px; display: grid; place-items: center; background: var(--ink-900); color: var(--paper); font-weight: 700; font-size: 12px; }
.ml-verify b { color: var(--ink-900); }
.ml-try p { color: var(--ink-600); margin: 0 0 14px; }
.ml-presets { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 8px; }
.ml-presets button { font: 500 13px/1 var(--sans); padding: 9px 12px; min-height: 36px; border: 1px dashed var(--brick-400); background: none; color: var(--brick-700); cursor: pointer; }
.ml-presets button:hover { background: var(--brick-100); }
.ml-field { display: grid; grid-template-columns: minmax(0,1fr) 150px; gap: 12px; align-items: center; padding: 10px 0; border-top: 1px solid var(--ink-200); }
.ml-field label { font: 600 14px/1.3 var(--sans); }
.ml-field label small { display: block; font-weight: 400; color: var(--ink-500); font-size: 12.5px; }
.ml-in { display: flex; align-items: center; background: var(--white); border: 1px solid var(--ink-300); padding: 0 10px; }
.ml-in:focus-within { border-color: var(--brick-500); box-shadow: 0 0 0 2px var(--brick-100); }
.ml-in span { color: var(--ink-500); font-size: 14px; }
.ml-in input { width: 100%; min-width: 0; border: 0; background: transparent; color: var(--ink-900); font: 700 16px/1 var(--sans); padding: 11px 4px; text-align: right; font-variant-numeric: tabular-nums; }
.ml-in input:focus { outline: none; }
.ml-field.changed .ml-in { border-color: var(--brick-500); background: var(--brick-100); }
.ml-live-box { margin-top: 14px; padding: 16px; background: var(--ink-900); color: var(--paper); }
.ml-big { font: 800 40px/1 var(--display); letter-spacing: -0.03em; font-variant-numeric: tabular-nums; }
.ml-vs { font-size: 14px; color: var(--ink-300); margin-top: 8px; }
.ml-src { list-style: none; margin: 0; padding: 0; }
.ml-src li { display: grid; grid-template-columns: minmax(0,1fr) auto; gap: 4px 12px; padding: 14px 0; border-top: 1px solid var(--ink-200); }
.ml-what { font-weight: 600; font-size: 14.5px; } .ml-val { font-weight: 700; text-align: right; font-variant-numeric: tabular-nums; }
.ml-from { grid-column: 1 / -1; font-size: 14px; line-height: 1.5; color: var(--ink-600); }
.ml-code { font-size: 12.5px; color: var(--ink-500); }
.ml-body details { border-top: 1px solid var(--ink-200); padding: 12px 0; }
.ml-body summary { font-weight: 600; font-size: 14.5px; cursor: pointer; }
.ml-body details p { font-size: 15px; color: var(--ink-600); margin: 8px 0 0; }
.ml-more { margin: 16px 0 0; font-size: 14px; }
@media (max-width: 480px) { .ml-field { grid-template-columns: minmax(0,1fr) 120px; } .ml-answer b { font-size: 40px; } }
@media (prefers-reduced-motion: reduce) { .ml, .ml-scrim, .ml-step, .ml-c, .article-layout { transition: none !important; } .ml-live { animation: none; outline: 2px solid var(--brick-500); } }

/* --- Oct 28 draft: one number per panel, source card, exhibit list --- */
.show-math { gap: 6px; }
.ml-back { justify-self: start; font: 600 13px/1 var(--sans); color: var(--brick-700); background: none; border: 0; padding: 6px 0; cursor: pointer; }
.ml-back[hidden], .ml-tabs[hidden] { display: none; }
.ml-srccard { border: 1px solid var(--ink-200); background: var(--white, #fff); padding: 16px 18px; margin: 16px 0 0; }
.ml-srccard p { margin: 0 0 6px; font-size: 15px; line-height: 1.5; color: var(--ink-600); }
.ml-srccard .ml-srck { font: 700 11px/1.3 var(--sans); letter-spacing: .12em; text-transform: uppercase; color: var(--ink-500); margin-bottom: 8px; }
.ml-srccard .ml-srcname { font-weight: 600; color: var(--ink-900); }
.ml-srccard .ml-srcmeta { font-size: 13px; color: var(--ink-500); }
.ml-srccard a { display: inline-block; margin-top: 6px; font-weight: 600; color: var(--brick-700); }
.ml-list { list-style: none; margin: 16px 0 0; padding: 0; border-top: 1px solid var(--ink-200); }
.ml-list button { width: 100%; display: grid; grid-template-columns: 76px 1fr auto 16px; gap: 12px; align-items: center; text-align: left; background: none; border: 0; border-bottom: 1px solid var(--ink-200); padding: 14px 2px; cursor: pointer; font: 500 15px/1.35 var(--sans); color: var(--ink-900); }
.ml-list button:hover { background: var(--ink-100); }
.ml-list b { font: 800 20px/1 var(--display); letter-spacing: -0.02em; }
.ml-list em { font-style: normal; font-size: 12px; font-weight: 600; color: var(--ink-500); white-space: nowrap; }
.ml-list em.calc { color: var(--brick-700); }
.ml-list i { font-style: normal; color: var(--ink-400); }