/* manimo concept playground — themed per paper via CSS vars (set from the manifest theme by app.js). */
:root {
  --bg: #0E1116; --ink: #E8EDF3; --muted: #8B95A1; --accent: #58A6FF; --accent2: #BC8CFF; --card: #161b22;
  --clip-bg: #0A0D13;   /* close to the Manim clips' encoded dark bg — the video dissolves into it */
  --r: 14px; --fast: .22s; --mono: ui-monospace, SFMono-Regular, Menlo, monospace;
}
* { box-sizing: border-box; }
body { margin: 0; font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif; background: #0b0e13; color: #e8edf3; -webkit-font-smoothing: antialiased; }

.topbar { display: flex; align-items: baseline; gap: 14px; padding: 16px 24px; border-bottom: 1px solid #1c2230; position: sticky; top: 0; background: rgba(11,14,19,.85); backdrop-filter: blur(8px); z-index: 5; }
.brand { font-weight: 700; font-size: 19px; letter-spacing: .2px; }
.brand span { color: #6b7686; font-weight: 500; }
.tagline { color: #6b7686; font-size: 13px; }

.layout { display: grid; grid-template-columns: 260px 1fr; min-height: calc(100vh - 58px); }
.nav { border-right: 1px solid #1c2230; padding: 14px 10px; display: flex; flex-direction: column; gap: 6px; position: sticky; top: 58px; align-self: start; max-height: calc(100vh - 58px); overflow: auto; }
.nav-item { text-align: left; background: transparent; border: 1px solid transparent; color: #c9d3df; padding: 10px 12px; border-radius: 10px; cursor: pointer; display: flex; flex-direction: column; gap: 2px; transition: var(--fast); }
.nav-item:hover { background: #131923; }
.nav-item.on { background: #131923; border-color: #2a3346; }
.nav-t { font-weight: 600; font-size: 14px; }
.nav-s { font-size: 11px; color: #6b7686; }

.main { padding: 26px 30px 80px; background: var(--bg); color: var(--ink); transition: background var(--fast); }
.paper-head h1 { margin: 0 0 4px; font-size: 26px; }
.paper-head .sub { margin: 0 0 18px; color: var(--muted); }
.empty, .err { color: var(--muted); padding: 30px 0; }
.err { color: #ff8a8a; }

.card { background: var(--card); border: 1px solid rgba(255,255,255,.06); border-radius: var(--r); margin: 16px 0; overflow: hidden; box-shadow: 0 10px 30px rgba(0,0,0,.25); }
.card-h { display: flex; align-items: center; justify-content: space-between; padding: 13px 18px; border-bottom: 1px solid rgba(255,255,255,.06); }
.card-t { font-weight: 700; font-size: 16px; color: var(--ink); }
.tag { font-size: 11px; color: var(--bg); background: var(--accent); padding: 3px 9px; border-radius: 999px; font-weight: 600; }
.card-b { padding: 18px; }
.explainer { color: var(--muted); margin: 0 0 14px; line-height: 1.5; max-width: 70ch; }

.row { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; }
.row.mats, .row.heat { align-items: flex-start; }
.ctrls { margin: 14px 0; gap: 10px; }
.sliders { gap: 18px; margin-top: 10px; }
.matcol { display: flex; flex-direction: column; gap: 6px; }
.matlbl { font-size: 12px; color: var(--muted); }
.op { font-size: 22px; color: var(--accent2); align-self: center; padding-top: 18px; }

table.mx { border-collapse: collapse; }
table.mx td { padding: 2px; }
input.cell { width: 46px; height: 34px; text-align: center; border: 1px solid rgba(255,255,255,.12); background: rgba(255,255,255,.03); color: var(--ink); border-radius: 8px; font-variant-numeric: tabular-nums; transition: var(--fast); }
input.cell:focus { outline: none; border-color: var(--accent); }
input.cell.hot { background: color-mix(in srgb, var(--accent) 28%, transparent); border-color: var(--accent); }
input.cell[readonly] { background: rgba(255,255,255,.02); color: var(--accent2); font-weight: 700; }

.btn { background: var(--accent); color: var(--bg); border: 0; padding: 9px 16px; border-radius: 10px; font-weight: 600; cursor: pointer; transition: var(--fast); }
.btn:hover { filter: brightness(1.08); transform: translateY(-1px); }
.btn.ghost { background: transparent; color: var(--ink); border: 1px solid rgba(255,255,255,.18); }
.chip { display: inline-block; background: rgba(255,255,255,.06); color: var(--ink); padding: 4px 10px; border-radius: 999px; font-size: 12px; }
.chip.acc { background: var(--accent2); color: var(--bg); font-weight: 600; }
.fld { display: inline-flex; align-items: center; gap: 8px; color: var(--muted); font-size: 13px; }
.fld input[type=range] { accent-color: var(--accent); }
.sval { color: var(--accent2); font-variant-numeric: tabular-nums; min-width: 34px; }
.sel, .lbledit { background: rgba(255,255,255,.04); color: var(--ink); border: 1px solid rgba(255,255,255,.14); border-radius: 8px; padding: 6px 8px; }
.lbledit { min-width: 260px; }
.readout { font-family: var(--mono); font-size: 13px; color: var(--ink); }

canvas.heat, canvas.plot { background: var(--bg); border: 1px solid rgba(255,255,255,.08); border-radius: 10px; }

.steps { margin-top: 14px; background: rgba(0,0,0,.18); border: 1px solid rgba(255,255,255,.06); border-radius: 10px; padding: 10px 12px; max-height: 190px; overflow: auto; font-family: var(--mono); font-size: 12.5px; }
.steps-h { color: var(--muted); font-family: system-ui; font-size: 12px; margin-bottom: 6px; text-transform: uppercase; letter-spacing: .4px; }
.step { padding: 3px 0; color: #c9d3df; opacity: .8; }
.step.acc { color: var(--ink); opacity: 1; border-left: 2px solid var(--accent2); padding-left: 8px; }
.step b { color: var(--accent2); }

/* narrative beat header (problem / prior work / takeaway …) */
.beat-head { display: flex; align-items: center; gap: 10px; margin: 0 0 8px; }
.beat-kind { font-size: 11px; font-weight: 700; letter-spacing: .5px; text-transform: uppercase; color: var(--bg);
  background: linear-gradient(135deg, var(--accent), var(--accent2)); padding: 3px 10px; border-radius: 999px; }
.beat-ttl { color: var(--ink); font-weight: 600; font-size: 15px; }

/* results: metric cards */
.metrics { display: flex; flex-wrap: wrap; gap: 12px; }
.metric { background: rgba(255,255,255,.04); border: 1px solid rgba(255,255,255,.08); border-radius: 12px; padding: 14px 18px; min-width: 130px; animation: pop var(--fast) both; }
.m-val { font-size: 26px; font-weight: 800; color: var(--accent2); font-variant-numeric: tabular-nums; }
.m-name { font-size: 12px; color: var(--muted); margin-top: 2px; }
.m-delta { font-size: 12px; color: var(--accent); margin-top: 4px; font-weight: 600; }
canvas.chart { width: 100%; max-width: 560px; }

/* compare: existing approaches vs this work */
.diagram.compare { align-items: stretch; gap: 14px; }
.vs-col { flex: 1 1 0; min-width: 140px; display: flex; flex-direction: column; gap: 8px; padding: 12px; border-radius: 12px; border: 1px solid rgba(255,255,255,.08); }
.vs-col.old { background: rgba(255,255,255,.03); }
.vs-col.new { background: color-mix(in srgb, var(--accent) 12%, transparent); border-color: color-mix(in srgb, var(--accent) 40%, transparent); }
.vs-h { font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: .4px; color: var(--muted); margin-bottom: 2px; }
.vs-col.new .vs-h { color: var(--accent2); }
.vs-mid { align-self: center; color: var(--accent2); font-weight: 800; font-size: 15px; padding: 0 2px; }

/* generic diagram */
.diagram { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; padding: 16px 4px; }
.diagram.vert { flex-direction: column; align-items: flex-start; }
.diagram .node { background: var(--card); border: 2px solid var(--accent); color: var(--ink); padding: 9px 14px; border-radius: 10px; font-weight: 600; animation: pop var(--fast) both; }
.diagram .node.root { border-color: var(--accent2); }
.diagram .kids { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 8px; }
.diagram .arrow { color: var(--accent2); font-size: 20px; }
.node.flowy { box-shadow: 0 0 0 0 var(--accent); animation: pop var(--fast) both, glow 2.4s ease-in-out infinite; }
@keyframes pop { from { opacity: 0; transform: translateY(6px) scale(.92); } to { opacity: 1; transform: none; } }
@keyframes glow { 0%,100% { box-shadow: 0 0 0 0 transparent; } 50% { box-shadow: 0 0 16px -2px var(--accent); } }

/* ── Play-all transport: one click → the whole paper animates in order, like the Manim video ── */
.transport {
  position: sticky; top: 58px; z-index: 4;
  display: flex; gap: 16px; align-items: center;
  padding: 14px 16px; margin: 4px 0 20px;
  border: 1px solid rgba(255,255,255,.10); border-radius: 16px;
  background:
    radial-gradient(140% 180% at 0% 0%, color-mix(in srgb, var(--accent) 16%, transparent), transparent 58%),
    color-mix(in srgb, var(--bg) 78%, #000);
  backdrop-filter: blur(10px);
  box-shadow: 0 12px 34px rgba(0,0,0,.35);
}
.transport .tbtns { display: flex; gap: 8px; flex: 0 0 auto; }
.transport .tmeta { flex: 1 1 auto; min-width: 0; display: flex; flex-direction: column; gap: 9px; }
.transport .caprow { display: flex; align-items: baseline; gap: 12px; justify-content: space-between; }
.transport .cap { color: var(--ink); font-size: 13.5px; font-weight: 500; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.transport .cap.ok { color: var(--accent2); }
.transport .count { color: var(--muted); font-size: 12px; font-variant-numeric: tabular-nums; font-family: var(--mono); flex: 0 0 auto; }
.transport .rail { height: 6px; border-radius: 999px; background: rgba(255,255,255,.10); overflow: hidden; }
.transport .rail .fill { display: block; height: 100%; width: 0; border-radius: 999px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  box-shadow: 0 0 12px -1px var(--accent);
  transition: width .45s cubic-bezier(.4, 0, .2, 1); }
.btn.play { font-size: 14px; padding: 11px 20px; color: #fff;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  box-shadow: 0 6px 18px -4px var(--accent); }
.btn.play:hover { filter: brightness(1.07); }
.btn[disabled] { opacity: .42; cursor: default; transform: none; filter: none; box-shadow: none; }

/* cinema spotlight: the playing card glows, the rest recede */
.card { transition: var(--fast), opacity .35s ease, transform .35s ease, box-shadow .35s ease, border-color .35s ease; }
.main:has(.card.playing) .card:not(.playing) { opacity: .4; filter: saturate(.72); }
.card.playing { border-color: color-mix(in srgb, var(--accent) 55%, transparent);
  box-shadow: 0 0 0 1px var(--accent), 0 0 30px -4px var(--accent), 0 22px 52px rgba(0,0,0,.45);
  transform: translateY(-2px); }
.card.playing .card-h { background: linear-gradient(90deg, color-mix(in srgb, var(--accent) 14%, transparent), transparent); }

/* numbered storyboard badge on every card */
.card-h { gap: 10px; }
.card-t { flex: 1 1 auto; }
.card-n { font-family: var(--mono); font-size: 12px; font-weight: 700; color: var(--bg);
  background: var(--accent2); border-radius: 7px; padding: 2px 7px; letter-spacing: .5px; }

/* interconnection: a value flowing from one card into the next */
.flowlink { display: flex; align-items: center; gap: 9px; margin: -4px 0 -2px; padding: 6px 18px; color: var(--muted); font-size: 12.5px; }
.flowlink::before { content: ""; width: 2px; height: 20px; margin-left: 11px;
  background: linear-gradient(var(--accent), var(--accent2)); border-radius: 2px; }
.flow-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent2); box-shadow: 0 0 10px -1px var(--accent2); flex: 0 0 auto; }
.flow-var { font-family: var(--mono); font-weight: 700; color: var(--accent2);
  background: color-mix(in srgb, var(--accent2) 16%, transparent); padding: 1px 8px; border-radius: 6px; }
.flow-txt { color: var(--muted); }

/* token-row labels next to the input matrix */
.rowlbls { display: flex; flex-direction: column; gap: 2px; padding-top: 2px; }
.rowlbl { height: 36px; display: flex; align-items: center; color: var(--accent2); font-family: var(--mono); font-size: 12px; }

@media (prefers-reduced-motion: reduce) {
  .card, .transport .rail .fill { transition: none; }
  .card.playing { transform: none; }
  /* kill the JS-staggered reveals + infinite glow + count-up pop for motion-sensitive users */
  .diagram .node, .node.flowy, .metric { animation: none !important; }
  /* water-drop flow: drop still moves (it tracks the slide) but without the bouncy stretch/ripple/shimmer */
  .flow-stream::after, .flow-drop .bulb, .flow-ripple, body.theater .card.playing .card-b { animation: none !important; }
  .flow-drop, .flow-fill { transition: top .01s linear, height .01s linear; }
}

@media (max-width: 760px) {
  .layout { grid-template-columns: 1fr; } .nav { flex-direction: row; overflow-x: auto; position: static; max-height: none; }
  .transport { flex-direction: column; align-items: stretch; }
}

/* ── Theater mode: "Play all" goes big-screen ──────────────────────────────────────────────────────
 * Auto-entered (and OS-fullscreen requested) the instant Play all is pressed. Nav + topbar fold away,
 * the page narrows to a single column, and the ONE playing card fills the viewport so its animation is
 * large and legible — the rest hide so there's a single clear focus, like the Manim video full-frame.
 * Placed after the mobile query so its hiding wins even on small screens. */
body.theater { overflow: hidden; }
body.theater .topbar { display: none; }
body.theater .layout { grid-template-columns: 1fr; min-height: 100vh; }
body.theater .nav { display: none; }
body.theater .main { padding: 8px 2.5vw 0; min-height: 100vh; }
body.theater .paper-head, body.theater .flowlink { display: none; }
body.theater .transport { top: 0; margin: 0 0 8px; }

/* one card on stage, centered, filling the whole screen below the transport; the rest step aside */
body.theater .card { display: none; }
body.theater .card.playing {
  display: flex; flex-direction: column; margin: 0; overflow: hidden; transform: none;
  height: calc(100vh - 104px); width: 100%; border-radius: 18px;
}
body.theater .card.playing .card-h { padding: 14px 28px; }
body.theater .card.playing .card-t { font-size: 24px; }
body.theater .card.playing .card-b {
  flex: 1 1 auto; min-height: 0; overflow: auto;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 16px; padding: 18px 24px;
}
body.theater .card.playing .row { justify-content: center; gap: 3vw; }
body.theater .card.playing .ctrls { justify-content: center; }

/* enlarge the actual animation surfaces so they truly use the screen */
body.theater .card.playing canvas.heat { width: min(40vh, 38vw); height: min(40vh, 38vw); }
body.theater .card.playing canvas.plot { width: min(82vw, 1280px); height: auto; max-height: 60vh; }
body.theater .card.playing canvas.chart { width: min(82vw, 1280px); max-width: none; height: auto; max-height: 60vh; }
body.theater .card.playing input.cell { width: 66px; height: 50px; font-size: 21px; }
body.theater .card.playing .rowlbl { height: 52px; font-size: 15px; }
body.theater .card.playing .matlbl { font-size: 15px; }
body.theater .card.playing .op { font-size: 34px; padding-top: 24px; }
body.theater .card.playing .steps { font-size: 15px; max-height: 18vh; width: min(82vw, 1280px); }
body.theater .card.playing .diagram { padding: 8px; gap: 14px; }
body.theater .card.playing .diagram .node { font-size: 22px; padding: 16px 24px; }
body.theater .card.playing .vs-col { padding: 20px; min-width: 220px; }
body.theater .card.playing .metric { padding: 24px 34px; min-width: 190px; }
body.theater .card.playing .m-val { font-size: 44px; }
body.theater .card.playing .explainer { font-size: 17px; max-width: 90ch; text-align: center; }

/* narration toggle sits with the transport buttons */
.transport .btn.mute { padding: 9px 13px; font-size: 15px; line-height: 1; }

/* ── Manim clip hero: the real 3D Manim animation tops each slide; the widget sits below as "try it" ──
 * Seamless background: NO border/box — the clip's dark bg is feathered on all four edges so the video
 * dissolves into the page (the Manim scenes render on the same dark palette as the site). The feather
 * survives re-rendering, so it works no matter the exact encoded bg of each clip. */
.hero-wrap { display: flex; justify-content: center; margin: 0 0 4px; background: transparent; }
.manim-hero { width: 100%; max-width: 820px; display: block; border-radius: 14px; background: var(--clip-bg);
  -webkit-mask-image:
    linear-gradient(to right, transparent, #000 3%, #000 97%, transparent),
    linear-gradient(to bottom, transparent, #000 3.5%, #000 96.5%, transparent);
  -webkit-mask-composite: source-in;
  mask-image:
    linear-gradient(to right, transparent, #000 3%, #000 97%, transparent),
    linear-gradient(to bottom, transparent, #000 3.5%, #000 96.5%, transparent);
  mask-composite: intersect; }
.tryit { font-size: 11px; text-transform: uppercase; letter-spacing: .6px; color: var(--muted);
  display: flex; align-items: center; gap: 10px; margin: 12px 0 14px; }
.tryit::before, .tryit::after { content: ""; flex: 1 1 auto; height: 1px; background: rgba(255,255,255,.10); }

/* in theater (Play-all), the Manim clip IS the slide — go big, hide the widget, and drop the card panel
 * so the feathered video sits straight on the page background (fully seamless). */
body.theater .card.playing { background: transparent; box-shadow: none; border-color: transparent; }
body.theater .card.playing .card-h { background: transparent; border-bottom-color: rgba(255,255,255,.06); }
body.theater .card.playing .manim-hero { max-width: min(88vw, 1360px); max-height: 74vh; }
body.theater .card.playing .widget-body, body.theater .card.playing .tryit { display: none; }
/* hide the native video control-bar during Play-all so the clip is fully seamless — the transport +
 * flow rail drive playback; the gallery (non-theater) keeps controls so you can scrub each clip. */
body.theater .manim-hero::-webkit-media-controls { display: none !important; }
body.theater .manim-hero::-webkit-media-controls-enclosure { display: none !important; }
/* each new slide's content rises in from below as the drop falls to it — the "flowing down" feel */
body.theater .card.playing .card-b { animation: riseIn .55s cubic-bezier(.2,.7,.2,1) both; }
@keyframes riseIn { from { opacity: 0; transform: translateY(46px); } to { opacity: 1; transform: none; } }

/* ── Water-drop flow rail: a glowing teardrop descends a vertical stream, pausing at each slide ──────
 * Visible during Play-all (theater). One station per slide; the drop FALLS to the active station (a
 * gravity-eased transition), LANDS with a ripple while the slide's video plays, then falls to the next.
 * The stream shimmers like flowing water; the fill above the drop shows progress. */
.flowrail { position: fixed; left: 20px; top: 64px; bottom: 18px; width: 46px; z-index: 30;
  display: none; pointer-events: none; }
body.theater .flowrail { display: block; }
.flow-stream { position: absolute; left: 50%; top: 4%; bottom: 4%; width: 3px; transform: translateX(-50%);
  border-radius: 3px; background: rgba(255,255,255,.09); overflow: hidden; }
.flow-stream::after { content: ""; position: absolute; left: 0; right: 0; top: 0; height: 40%;
  background: linear-gradient(180deg, transparent, color-mix(in srgb, var(--accent) 75%, transparent), transparent);
  animation: streamflow 2.4s linear infinite; }
@keyframes streamflow { from { transform: translateY(-120%); } to { transform: translateY(360%); } }
.flow-fill { position: absolute; left: 50%; top: 4%; width: 3px; height: 0; transform: translateX(-50%);
  border-radius: 3px; background: linear-gradient(180deg, var(--accent), var(--accent2));
  box-shadow: 0 0 10px -1px var(--accent); transition: height .72s cubic-bezier(.5,0,.35,1); }
.flow-station { position: absolute; left: 50%; width: 11px; height: 11px; transform: translate(-50%,-50%);
  border-radius: 50%; background: #1b2230; border: 1.5px solid #2a3346; transition: var(--fast); z-index: 2; }
.flow-station.done { background: var(--accent2); border-color: var(--accent2); box-shadow: 0 0 8px -1px var(--accent2); }
.flow-station.active { background: var(--accent); border-color: #fff; box-shadow: 0 0 16px 0 var(--accent); transform: translate(-50%,-50%) scale(1.25); }
.flow-ripple { position: absolute; left: 50%; width: 12px; height: 12px; transform: translate(-50%,-50%);
  border-radius: 50%; border: 2px solid var(--accent); opacity: 0; pointer-events: none; z-index: 1; }
.flow-ripple.go { animation: rippleout .85s ease-out; }
@keyframes rippleout { 0% { opacity: .9; width: 8px; height: 8px; } 100% { opacity: 0; width: 64px; height: 64px; } }
.flow-drop { position: absolute; left: 50%; top: 4%; width: 22px; height: 22px; transform: translate(-50%,-50%);
  transition: top .72s cubic-bezier(.5,0,.35,1); z-index: 3; }
.flow-drop .bulb { width: 100%; height: 100%; border-radius: 0 50% 50% 50%; transform: rotate(45deg);
  background: radial-gradient(circle at 32% 28%, #fff, var(--accent) 46%, var(--accent2) 100%);
  box-shadow: 0 0 18px 2px color-mix(in srgb, var(--accent) 70%, transparent); }
.flow-drop.falling .bulb { animation: dropstretch .72s ease-in; }
@keyframes dropstretch { 0% { transform: rotate(45deg) scale(1,1); } 40% { transform: rotate(45deg) scale(.82,1.25); } 100% { transform: rotate(45deg) scale(1,1); } }
.flow-drop.land .bulb { animation: dropland .5s ease-out; }
@keyframes dropland { 0% { transform: rotate(45deg) scale(1.18,.8); } 55% { transform: rotate(45deg) scale(.84,1.18); } 100% { transform: rotate(45deg) scale(1,1); } }
/* clear the rail in theater so cards don't sit under it */
body.theater .main { padding-left: 78px; }