:root{
  --ink:#102f35; --ink2:#163b42; --paper:#f2efe7; --surface:#fff; --surface2:#faf8f3;
  --muted:#6c7a7d; --line:#d9dad5; --line2:#e8e7e1; --accent:#c84b3d; --teal:#267a76;
  --teal-soft:#e8f1ee; --red-soft:#f6e8e2; --serif:Iowan Old Style,Baskerville,Palatino Linotype,Georgia,serif;
  --sans:Inter,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--sans);line-height:1.45}
button,input,select{font:inherit}
button{cursor:pointer}
a{color:inherit}
.skip-link{position:absolute;left:-9999px}.skip-link:focus{left:1rem;top:1rem;z-index:999;background:#fff;padding:.6rem 1rem}

/* Compact product masthead: the experiment, not chrome, owns the page. */
.masthead{height:112px;background:#103a3f;color:#f8f4eb;padding:0 clamp(1rem,3vw,3rem);display:flex;align-items:center}
.mast-inner{width:min(1500px,100%);margin:auto;display:flex;align-items:center;justify-content:space-between;gap:1.2rem}
.eyebrow,.small-label{margin:0;text-transform:uppercase;letter-spacing:.13em;font-size:.63rem;font-weight:850}
.masthead .eyebrow,.presentation-header .eyebrow{color:#df725e}
.masthead h1{margin:.2rem 0 0;font-family:var(--serif);font-size:clamp(2rem,3.7vw,3.35rem);font-weight:500;letter-spacing:-.04em;line-height:.95}
.mast-actions{display:flex;gap:1rem}.mast-actions a{font-size:.72rem;text-decoration:none;color:#d8e2df}.mast-actions a:hover{text-decoration:underline}

.app-shell{width:min(1600px,100%);margin:auto;display:grid;grid-template-columns:258px minmax(0,1fr);min-height:calc(100vh - 112px);background:var(--surface)}
.journey{border-right:1px solid var(--line);background:#efede6;padding:1rem .8rem;min-width:0}
.journey-heading{display:flex;justify-content:space-between;align-items:center;padding:.25rem .45rem .7rem}
.journey-heading strong{font-family:var(--serif);font-size:.86rem;font-weight:500;color:var(--muted)}
.point-navigation{display:grid;gap:.06rem;max-height:calc(100vh - 225px);overflow:auto;padding-right:.2rem;scrollbar-width:thin}
.part-label{padding:.9rem .5rem .25rem;color:var(--muted);font-size:.58rem;font-weight:850;text-transform:uppercase;letter-spacing:.09em;line-height:1.25}
.point-button{display:grid;grid-template-columns:28px minmax(0,1fr) 14px;gap:.4rem;align-items:center;width:100%;border:0;background:transparent;color:var(--ink);text-align:left;padding:.42rem .5rem;border-radius:7px;line-height:1.15}
.point-button:hover{background:rgba(255,255,255,.62)}
.point-button[aria-current=step]{background:#fff}
.point-number{font-family:var(--serif);color:var(--accent);font-size:.92rem}.point-name{font-size:.7rem;font-weight:720}.nav-check{font-size:.65rem;color:var(--teal)}
.progress-area{margin-top:.8rem;padding:.7rem .4rem 0;border-top:1px solid var(--line)}.progress-meta{display:flex;justify-content:space-between;color:var(--muted);font-size:.65rem}
.progress-track{height:3px;background:#d5d3cc;margin-top:.45rem}.progress-bar{height:100%;background:var(--accent);width:0;transition:width .2s}

.presentation{min-width:0;background:var(--surface)}
.presentation-header{position:sticky;top:0;z-index:40;min-height:86px;display:flex;align-items:center;justify-content:space-between;gap:1rem;padding:1rem clamp(1rem,2.8vw,2.1rem);border-bottom:1px solid var(--line);background:rgba(255,255,255,.95);backdrop-filter:blur(10px)}
.presentation-header h2{margin:.22rem 0 0;font-family:var(--serif);font-size:clamp(1.6rem,2.6vw,2.45rem);font-weight:500;letter-spacing:-.035em;line-height:1}
.navigation-buttons{display:flex;gap:.45rem;flex-shrink:0;align-items:center}
button{border:1px solid #cdd0cb;background:#fff;color:var(--ink);padding:.55rem .72rem;border-radius:7px;font-weight:760;font-size:.75rem}
button:hover{border-color:#aeb6b2}.primary-button{background:var(--accent);border-color:var(--accent);color:#fff}.primary-button:hover{border-color:#a93e33}.icon-button{min-width:36px;padding:.5rem}.quiet-button{background:transparent}.command-launch{display:flex;align-items:center;gap:.42rem}.keycap{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.64rem;border:1px solid var(--line);padding:.08rem .26rem;border-radius:4px;background:#f6f4ee}button:disabled{opacity:.35;cursor:default}

.experiment-pane{padding:clamp(1rem,2.8vw,2.2rem);min-width:0;max-width:1180px;width:100%;margin:0 auto}
.question-block{display:grid;grid-template-columns:auto minmax(0,1fr);gap:1rem;align-items:start;padding-bottom:1rem;border-bottom:1px solid var(--line)}
.work-index{font-family:var(--serif);color:var(--accent);font-size:1rem;line-height:1.25;padding-top:.15rem}
.question-block h3{margin:0;font-family:var(--serif);font-size:clamp(1.35rem,2.2vw,1.9rem);font-weight:500;line-height:1.16;max-width:900px}
.experiment-content{padding-top:1.15rem}

/* One concept, one instrument. */
.instrument{border:1px solid var(--line);background:#fff;min-width:0}
.control-rail{display:flex;align-items:end;gap:1rem;flex-wrap:wrap;padding:.85rem 1rem;border-bottom:1px solid var(--line);background:#fbfaf6}
.control{display:grid;gap:.3rem;flex:1 1 190px;min-width:160px;max-width:330px}
.control-head{display:flex;justify-content:space-between;gap:1rem;align-items:baseline}.control label{font-size:.68rem;color:var(--ink);font-weight:760}.control output{font-family:var(--serif);font-size:.85rem;color:var(--accent)}
.control select{width:100%;padding:.48rem .55rem;border:1px solid var(--line);border-radius:6px;background:#fff;color:var(--ink);font-size:.72rem}
.range-input{--pct:50%;width:100%;height:18px;margin:0;appearance:none;background:transparent;cursor:ew-resize}
.range-input::-webkit-slider-runnable-track{height:3px;border-radius:3px;background:linear-gradient(90deg,var(--accent) 0 var(--pct),#d8dbd6 var(--pct) 100%)}
.range-input::-webkit-slider-thumb{appearance:none;width:15px;height:15px;border-radius:50%;background:#fff;border:2px solid var(--accent);margin-top:-6px;box-shadow:0 1px 3px rgba(20,45,50,.18)}
.range-input::-moz-range-track{height:3px;background:#d8dbd6}.range-input::-moz-range-progress{height:3px;background:var(--accent)}.range-input::-moz-range-thumb{width:13px;height:13px;border-radius:50%;background:#fff;border:2px solid var(--accent)}
.checkbox-control{display:flex;align-items:center;gap:.5rem;flex:0 0 auto;min-height:34px}.checkbox-control input{accent-color:var(--accent)}.checkbox-control label{font-size:.7rem;font-weight:740}
.action-row{display:flex;align-items:center;gap:.45rem;flex-wrap:wrap}.action-row button{padding:.5rem .65rem}
.visual-frame{position:relative;min-height:410px;padding:1rem;overflow:hidden;background:#fff}
.visual-frame canvas{display:block;width:100%;height:auto;max-height:480px;object-fit:contain;touch-action:none}
.readout-row{display:flex;gap:.55rem;flex-wrap:wrap;padding:.75rem 1rem;border-top:1px solid var(--line2);background:#fff}
.readout{min-width:118px;display:grid;gap:.08rem}.readout span{color:var(--muted);font-size:.56rem;text-transform:uppercase;letter-spacing:.07em;font-weight:850}.readout strong{font-family:var(--serif);font-size:1rem;font-weight:500}
.caption{position:absolute;left:1rem;bottom:.75rem;color:var(--muted);font-size:.62rem;background:rgba(255,255,255,.84);padding:.2rem .35rem;border-radius:3px}
.visual-title{position:absolute;top:.65rem;left:.85rem;font-size:.57rem;color:var(--muted);font-weight:850;text-transform:uppercase;letter-spacing:.08em;z-index:2}

/* Insight drawer is optional, never a permanent text column. */
.insight-drawer{position:fixed;z-index:140;right:0;top:0;height:100vh;width:min(390px,92vw);background:#fbfaf7;border-left:1px solid var(--line);box-shadow:-20px 0 55px rgba(12,37,42,.14);transform:translateX(100%);transition:transform .2s ease;overflow:auto;padding-bottom:2rem}
body:not(.insight-closed) .insight-drawer{transform:translateX(0)}
.insight-head{position:sticky;top:0;display:flex;justify-content:space-between;align-items:center;padding:1rem 1.1rem;border-bottom:1px solid var(--line);background:#fbfaf7;z-index:2}
.insight-drawer section{padding:1rem 1.15rem;border-bottom:1px solid var(--line2)}.insight-drawer h3{margin:0 0 .35rem;font-family:var(--serif);font-size:1rem;font-weight:600}.insight-drawer p{margin:0;color:#42565a;font-size:.78rem}.insight-drawer .decision{background:#edf5f1}

/* Modal command interface inspired by coding tools: live stage controls first. */
body.modal-open{overflow:hidden}
.command-overlay,.shortcut-overlay{position:fixed;inset:0;z-index:220;background:rgba(9,29,33,.34);backdrop-filter:blur(5px);display:grid;place-items:start center;padding:7vh .8rem .8rem}
.command-overlay[hidden],.shortcut-overlay[hidden]{display:none}
.command-panel,.shortcut-panel{width:min(720px,100%);max-height:86vh;overflow:hidden;background:#fbfaf7;border:1px solid #cfd2cd;border-radius:10px;box-shadow:0 28px 80px rgba(10,27,32,.26)}
.command-panel-head,.shortcut-head{display:flex;align-items:start;justify-content:space-between;gap:1rem;padding:.8rem .9rem .7rem;border-bottom:1px solid var(--line)}
.command-panel-head h3,.shortcut-head h3{margin:.1rem 0 0;font-family:var(--serif);font-size:1.2rem;font-weight:600}.command-context{margin:.15rem 0 0;color:var(--muted);font-size:.66rem}
.command-stage-controls{padding:.75rem .9rem;border-bottom:1px solid var(--line);background:#f5f4ef;max-height:42vh;overflow:auto}.command-stage-controls[hidden]{display:none}
.palette-section-title{margin-bottom:.45rem;color:var(--muted);font-size:.56rem;font-weight:850;letter-spacing:.08em;text-transform:uppercase}
.palette-control-row{display:grid;grid-template-columns:150px minmax(0,1fr);align-items:center;gap:.8rem;padding:.35rem 0}.palette-control-meta{display:flex;align-items:baseline;justify-content:space-between;gap:.5rem;min-width:0}.palette-control-meta span{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:.69rem;font-weight:750}.palette-control-meta strong{font-family:var(--serif);font-size:.82rem;font-weight:500;color:var(--accent)}
.palette-control-input{width:100%;min-width:0}.palette-actions{display:flex;gap:.38rem;flex-wrap:wrap;margin-top:.5rem}.palette-actions button{padding:.38rem .55rem;font-size:.66rem}.palette-check{display:flex;gap:.45rem;align-items:center;font-size:.69rem}.palette-check input{accent-color:var(--accent)}
.command-input{margin:.65rem .75rem;width:calc(100% - 1.5rem);padding:.66rem .72rem;font-size:.76rem;border:1px solid var(--line);border-radius:6px;background:#fff}.command-results{max-height:30vh;overflow:auto;padding:.28rem}.command-result{display:flex;justify-content:space-between;align-items:center;width:100%;border:0;background:transparent;text-align:left;padding:.5rem .62rem;border-radius:5px}.command-result:hover,.command-result.selected{background:#efede6}.command-result strong{display:block;font-size:.7rem}.command-result small{display:block;color:var(--muted);font-size:.59rem;margin-top:.1rem}.command-enter{color:var(--muted);font-size:.65rem}
.shortcut-grid{display:grid;grid-template-columns:repeat(2,1fr);padding:.6rem}.shortcut-grid>div{padding:.75rem}.shortcut-grid kbd{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;border:1px solid var(--line);border-bottom-width:2px;border-radius:4px;padding:.1rem .3rem;background:#fff;font-size:.67rem}.shortcut-grid strong{display:block;margin-top:.35rem;font-family:var(--serif);font-size:.95rem}.shortcut-grid p{margin:.12rem 0 0;color:var(--muted);font-size:.64rem}.hari-toast{position:fixed;right:14px;bottom:14px;z-index:300;background:#102f35;color:#fff;padding:.55rem .7rem;border-radius:6px;font-size:.67rem;box-shadow:0 8px 25px rgba(0,0,0,.18)}

/* DOM visual primitives */
.bar-list{display:grid;gap:.62rem;padding:1rem 1.2rem}.bar-row{display:grid;grid-template-columns:120px minmax(0,1fr) 58px;gap:.6rem;align-items:center;font-size:.68rem}.bar-track{height:9px;background:#efeee9;border-radius:9px;overflow:hidden}.bar-fill{height:100%;background:var(--teal);border-radius:9px;transition:width .15s}.bar-fill.red{background:var(--accent)}.bar-row strong{font-family:var(--serif);font-size:.85rem;font-weight:500;text-align:right}
.bayes-flow{display:grid;grid-template-columns:1fr auto 1fr auto 1fr;align-items:center;gap:1rem;min-height:340px;padding:2rem}.bayes-node{border:1px solid var(--line);padding:1.2rem;background:#fff;text-align:center}.bayes-node span{display:block;color:var(--muted);font-size:.58rem;text-transform:uppercase;letter-spacing:.08em;font-weight:850}.bayes-node strong{display:block;margin-top:.3rem;font-family:var(--serif);font-size:2rem;font-weight:500}.bayes-arrow{font-family:var(--serif);font-size:1.6rem;color:var(--accent)}
.vote-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:.6rem;padding:2rem 1rem}.vote-card{min-height:130px;border:1px solid var(--line);display:grid;place-items:center;align-content:center;gap:.35rem;background:#fff}.vote-card span{font-size:.6rem;color:var(--muted);font-weight:800}.vote-card strong{font-family:var(--serif);font-size:1.7rem;font-weight:500}.vote-card.teal{background:var(--teal-soft)}.vote-card.red{background:var(--red-soft)}
.confusion-grid{display:grid;grid-template-columns:78px 1fr 1fr;gap:5px;padding:1rem;max-width:760px;margin:auto}.cm-head{display:grid;place-items:center;min-height:36px;color:var(--muted);font-size:.58rem;font-weight:850;text-transform:uppercase;letter-spacing:.05em}.cm-cell{min-height:130px;display:grid;place-items:center;align-content:center;gap:.2rem;background:rgba(38,122,118,var(--alpha));border:1px solid rgba(16,47,53,.06)}.cm-cell.bad{background:rgba(200,75,61,var(--alpha))}.cm-cell span{font-size:.58rem;font-weight:850;letter-spacing:.06em}.cm-cell strong{font-family:var(--serif);font-size:1.65rem;font-weight:500}
.decomposition{height:340px;display:grid;grid-template-columns:repeat(4,1fr);gap:.8rem;align-items:end;padding:1.3rem;background:#faf9f6}.decomp-bar{height:100%;display:grid;grid-template-rows:auto 1fr auto;gap:.35rem;text-align:center;align-items:end}.decomp-bar span{font-size:.58rem;color:var(--muted);font-weight:850;text-transform:uppercase;letter-spacing:.05em}.decomp-bar i{display:block;width:52%;min-height:4px;margin:auto;background:var(--teal);align-self:end;transition:height .15s}.decomp-bar:nth-child(2) i{background:var(--accent)}.decomp-bar:nth-child(3) i{background:#aeb8b5}.decomp-bar.total i{background:var(--ink)}.decomp-bar strong{font-family:var(--serif);font-size:.9rem;font-weight:500}
.dendrogram-wrap{padding:1rem}.silhouette-bars{display:flex;align-items:center;gap:3px;height:300px;padding:1rem;border-bottom:1px solid var(--line)}.silhouette-bar{flex:1;align-self:flex-end;background:var(--teal);min-width:2px}.silhouette-bar.bad{background:var(--accent)}

@media(max-width:1000px){.app-shell{grid-template-columns:220px minmax(0,1fr)}.control{min-width:145px}.bar-row{grid-template-columns:90px 1fr 50px}}
@media(max-width:760px){.masthead{height:82px;padding:.7rem 1rem}.masthead h1{font-size:1.7rem}.mast-actions{display:none}.app-shell{display:block;min-height:calc(100vh - 82px)}.journey{border-right:0;border-bottom:1px solid var(--line);padding:.55rem}.journey-heading,.progress-area{display:none}.point-navigation{display:flex;max-height:none;overflow:auto}.part-label{display:none}.point-button{min-width:150px;grid-template-columns:28px 1fr;padding:.4rem}.nav-check{display:none}.presentation-header{min-height:70px;padding:.65rem .75rem}.presentation-header h2{white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:47vw;font-size:1.45rem}.presentation-header .eyebrow{display:none}.command-launch span:last-child,.quiet-button{display:none}.experiment-pane{padding:.9rem}.question-block{gap:.6rem}.question-block h3{font-size:1.22rem}.control-rail{padding:.7rem}.control{flex:1 1 100%;max-width:none}.visual-frame{min-height:330px;padding:.55rem}.readout-row{padding:.6rem .7rem}.readout{min-width:88px}.bayes-flow{grid-template-columns:1fr;gap:.4rem;padding:1rem}.bayes-arrow{transform:rotate(90deg);text-align:center}.vote-grid{grid-template-columns:repeat(2,1fr);padding:1rem}.palette-control-row{grid-template-columns:1fr;gap:.2rem}.shortcut-grid{grid-template-columns:1fr}.bar-row{grid-template-columns:78px 1fr 44px}}
body.journey-hidden .app-shell{grid-template-columns:1fr}
body.journey-hidden .journey{display:none}

/* v3.1 — concise concept explanations */
.concept-explanation{
  display:grid;
  grid-template-columns:72px minmax(0,1fr);
  gap:1rem;
  align-items:start;
  padding:.85rem 0 1.05rem;
  border-bottom:1px solid var(--line2);
}
.concept-label{
  padding-top:.18rem;
  font-size:.63rem;
  line-height:1.2;
  letter-spacing:.12em;
  font-weight:700;
  color:#708185;
}
.concept-explanation p{
  margin:0;
  max-width:900px;
  color:#405357;
  font-size:.88rem;
  line-height:1.58;
}
@media(max-width:760px){
  .concept-explanation{grid-template-columns:1fr;gap:.3rem;padding:.7rem 0 .85rem}
  .concept-label{padding-top:0}
  .concept-explanation p{font-size:.82rem;line-height:1.5}
}