@charset "UTF-8";
:root{--ink:#142f38;--muted:#65777c;--bg:#f2f5f6;--line:#dce5e7;--teal:#087f79;--mint:#b9f0df;--orange:#d96239;--soft:#edf7f5;--blue:#447da0;--font:Inter,"Segoe UI","Microsoft YaHei",sans-serif}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.65 var(--font)}button,input,select{font:inherit}button,a,input,select{-webkit-tap-highlight-color:transparent}button{cursor:pointer}button:disabled{cursor:default;opacity:.5}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid #e9a448;outline-offset:4px}a{color:inherit}button{border:0}.topbar{height:88px;background:#102c35;color:#fff;display:flex;align-items:center;gap:32px;padding:0 5%;}.brand{display:flex;gap:14px;align-items:center;text-decoration:none;font-weight:650;letter-spacing:.06em}.brandmark{font:italic 30px Georgia,serif;border:1px solid #5c7c83;border-radius:10px;padding:1px 10px;color:var(--mint)}.brandmark span{font-size:24px}.brand-en{display:block;font-size:10px;letter-spacing:.2em;color:#a2bbc1;margin-top:1px}.course{margin-left:auto;font-size:13px;letter-spacing:.1em;color:#c5d7db}.course span{display:block;font-size:12px;letter-spacing:0;color:#8faab2}.quiet{background:transparent;color:var(--muted);padding:10px 8px;font-size:14px}.topbar .quiet{color:#d5e4e7;border-left:1px solid #35505a;padding-left:28px}main{max-width:1440px;margin:auto;padding:35px 5% 0}.intro{display:flex;align-items:center;justify-content:space-between;margin-bottom:30px}.eyebrow{font-size:12px;font-weight:700;letter-spacing:.15em;color:var(--teal);margin:0 0 8px}.intro h1{font-size:40px;line-height:1.3;letter-spacing:-.04em;margin:0 0 8px;font-weight:650}.intro h1 span{color:var(--teal)}.intro p:last-child{color:var(--muted);margin:0}.lesson-tag{display:flex;align-items:center;gap:18px;border-left:1px solid #b7c9ce;padding-left:26px}.lesson-tag b{font:58px/1 Georgia,serif}.lesson-tag span{font-size:14px;line-height:1.6;color:var(--muted)}.lesson-nav{display:grid;grid-template-columns:repeat(5,1fr);border-bottom:1px solid #ccd9dc;gap:18px;margin-bottom:28px}.lesson-nav button{background:transparent;padding:16px 0;color:#698087;font-size:15px;border-bottom:3px solid transparent;text-align:left;white-space:nowrap}.lesson-nav button span{font-size:12px;margin-right:8px;opacity:.65}.lesson-nav button.active{border-color:var(--teal);color:var(--teal);font-weight:700}.lesson-panel{display:none}.lesson-panel.active{display:block;animation:appear .25s ease}.section-heading{display:flex;align-items:center;justify-content:space-between;margin-bottom:22px;gap:16px}h2{font-size:24px;font-weight:650;line-height:1.45;margin:0}h3{font-size:21px;line-height:1.4;margin:0 0 12px}h4{font-size:17px;line-height:1.6;margin:5px 0 10px}p{margin:0 0 16px}.pill{font-size:12px;padding:5px 12px;border:1px solid #c7d9d8;border-radius:20px;color:var(--teal);white-space:nowrap}.scene-grid{display:grid;grid-template-columns:1.45fr 1fr;gap:32px;align-items:start}.experiment{border-radius:16px;background:#fff;border:1px solid var(--line);padding:24px 30px}.experiment-top{display:flex;justify-content:space-between;font-size:14px;color:var(--muted);padding-bottom:18px;border-bottom:1px solid var(--line)}.experiment-top span:first-child{font-weight:700;color:var(--ink)}.draw-zone{display:flex;align-items:center;justify-content:center;gap:32px;padding:26px 0}.suit-display{width:110px;height:138px;border:1px solid #d3dfe2;background:#f9fbfc;box-shadow:0 5px 0 #e5edef;border-radius:10px;display:flex;align-items:center;justify-content:center;font:72px Georgia,serif;color:#254e59}.draw-zone h3{margin-bottom:8px}.draw-zone p:last-child{font-size:14px;color:var(--muted);max-width:240px;margin:0}.suit-buttons{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}.suit-buttons button{font:36px Georgia,serif;color:var(--ink);background:#f3f7f8;border:1px solid #e1e9eb;border-radius:9px;padding:10px;transition:.18s}.suit-buttons button:hover{transform:translateY(-3px);border-color:var(--teal);background:#edf8f5}.suit-buttons span{display:block;font:13px var(--font);margin-top:6px;color:var(--muted)}.red{color:#cb513f!important}.game-actions{display:flex;align-items:center;gap:18px;margin:22px 0}.primary{background:var(--teal);color:#fff;border-radius:7px;font-size:15px;font-weight:600;padding:12px 20px}.primary:hover{background:#066c68}.primary span{margin-left:20px}.trial-grid{display:grid;grid-template-columns:repeat(20,1fr);gap:5px;margin:12px 0 14px}.trial{height:24px;background:#edf2f4;border-radius:3px;text-align:center;color:#a5b4b9;font-size:10px;line-height:24px}.trial.hit{background:#b9f0df;color:#09695b}.trial.miss{background:#dbe6e9;color:#82989e}.experiment-bottom{display:flex;justify-content:space-between;gap:8px;font-size:12px;color:var(--muted)}.experiment-bottom b{font-size:16px;color:var(--ink);margin:0 4px}.game-status{font-size:13px;color:var(--muted);border-top:1px solid var(--line);padding-top:15px;margin:17px 0 0;min-height:37px}.scene-note{padding:6px 0}.scene-note>p{color:var(--muted)}.scene-note>p.eyebrow{color:var(--teal)}.big-equation{font:24px/1.4 Georgia,"Microsoft YaHei",serif;border-block:1px solid #d0dddf;padding:16px 0;margin:20px 0}.big-equation span{padding:0 10px;color:var(--teal)}.question{border-left:3px solid var(--teal);padding:3px 0 0 18px;margin:25px 0}.question>span{font-size:12px;color:var(--teal);font-weight:700}.question p{font-size:14px;color:var(--muted);margin:0}.text-link{padding:0;background:none;color:var(--teal);font-size:15px;font-weight:600;text-decoration:none}.text-link span{margin-left:14px}footer{border-top:1px solid #d6e1e4;color:#798b91;font-size:12px;padding:20px 0;margin-top:32px;display:flex;justify-content:space-between;gap:20px}@keyframes appear{from{opacity:.5;transform:translateY(5px)}to{opacity:1;transform:none}}@media(min-width:1600px){main{padding-top:48px}.intro{margin-bottom:40px}.experiment{padding:32px 38px}.draw-zone{padding:34px 0}}@media(max-width:850px){.scene-grid{grid-template-columns:1fr}.intro h1{font-size:32px}.lesson-tag{display:none}.lesson-nav{gap:8px;overflow:auto;grid-template-columns:repeat(5,minmax(135px,1fr))}.lesson-nav button{font-size:14px}.course{display:none}.topbar .quiet{margin-left:auto}.topbar{padding:0 5%;height:76px}.section-heading{align-items:start}.pill{display:none}main{padding-top:24px}footer{flex-direction:column;gap:3px}.scene-note{padding-top:8px}}@media(max-width:480px){.experiment{padding:20px 16px}.draw-zone{gap:20px}.suit-display{width:88px;min-width:88px;height:118px}.draw-zone h3{font-size:18px}.draw-zone .eyebrow{font-size:10px}.suit-buttons{gap:8px}.experiment-bottom{flex-wrap:wrap}.trial-grid{grid-template-columns:repeat(10,1fr)}.intro p:last-child{font-size:14px}h2{font-size:21px}.brand-en{font-size:9px}.brand{font-size:14px}.topbar .quiet{padding-left:14px}.game-actions{gap:10px}}
/* A luminous, high-contrast laboratory surface. */
:root{--ink:#e2edf3;--muted:#8cabb9;--bg:#080f1b;--line:#24394a;--teal:#54dacd;--mint:#85efdc;--orange:#ff9569;--soft:#132d35;--blue:#4e9adb;color-scheme:dark}body{background:radial-gradient(ellipse at 70% 0%,#12304555,transparent 58%),var(--bg)}.topbar{background:#0b1524;border-bottom:1px solid #284052}.brandmark{border-color:#2c7180;background:#102c37;box-shadow:0 0 22px #42dbd510}.course{color:#b8d0dc}.intro h1{font-weight:600}.intro h1 span{color:#68e4db}.lesson-tag{border-color:#2c4353}.lesson-nav{border-color:#263c4d}.lesson-nav button{color:#8ca5b5}.lesson-nav button.active{text-shadow:0 0 16px #54dacd44}.lesson-nav button span{font-family:Consolas,monospace}.experiment{background:linear-gradient(135deg,#122131,#0c1a2a);border-color:#2a4558;box-shadow:0 15px 50px #0002}.suit-display{background:#0c1828;border-color:#315063;color:#b8e9ee;box-shadow:0 5px 0 #173344,0 0 40px #4cc8d60c}.suit-buttons button{background:#172c3b;border-color:#30495a;color:#c7dfed}.suit-buttons button:hover{background:#1c4047;border-color:#69e4d8}.red{color:#ff8c90!important}.primary{background:#6ce1d3;color:#0b2932;box-shadow:0 0 24px #60ebdb10}.primary:hover{background:#91f4e7}.trial{background:#1f3445;color:#7995a6}.trial.hit{background:#347f79;color:#d4fff5}.trial.miss{background:#253e51;color:#7697ad}.big-equation{border-color:#294252}.question{background:linear-gradient(90deg,#17394366,transparent);padding:12px 0 12px 18px}.pill{border-color:#285759;background:#12333377}.game-status{border-color:#2a4151}.topbar .quiet{border-color:#2c4150}.trial-grid{gap:4px}footer{border-color:#243847;color:#6f919f}button{transition:background .18s,border-color .18s,transform .18s}.topbar .brand-en{font-size:11px}.eyebrow{letter-spacing:.16em}.experiment-top{border-color:#29404f}.intro{margin-bottom:23px}

/* Teaching surfaces */
.workspace{display:grid;grid-template-columns:260px minmax(0,1fr);gap:24px}.panel{background:#101e2e;border:1px solid var(--line);border-radius:13px;padding:24px}.controls{align-self:start}.control{padding-bottom:23px;margin-bottom:23px;border-bottom:1px solid var(--line)}.control:last-child{border:0;margin:0;padding-bottom:0}.control label,.control-label{display:flex;align-items:center;justify-content:space-between;font-size:14px;font-weight:600;margin-bottom:12px}.control output{font:25px/1 Consolas,monospace;color:var(--teal)}.control small{display:block;font-size:12px;color:var(--muted);margin-top:8px}.range-ends{display:flex;justify-content:space-between;font:12px Consolas,monospace;color:var(--muted)}input[type=range]{width:100%;height:20px;accent-color:var(--teal);cursor:pointer}select{width:100%;background:#192f41;color:var(--ink);border:1px solid #3b596d;border-radius:6px;padding:10px}.segmented{display:flex;gap:5px}.segmented button{flex:1;background:#182e40;border:1px solid #2f495d;color:#a8c1cf;border-radius:6px;padding:9px 7px;font-size:14px}.segmented button.selected{color:var(--mint);background:#173f45;border-color:#51a9a6}.field-note{font-size:13px;color:var(--muted);margin:12px 0 0}.control-title{font-size:12px;letter-spacing:.12em;color:var(--muted);margin-bottom:20px}.chart-panel{padding:22px 26px}.chart-heading{display:flex;justify-content:space-between;align-items:start;gap:12px}.chart-heading h3{font-size:18px;margin:0}.math{font-family:Cambria,"Times New Roman",serif;letter-spacing:.02em}.math.big{font-size:32px}.chart-sub{font-size:13px;color:var(--muted);margin:4px 0 0}.chart-toolbar{display:flex;gap:4px;margin-bottom:10px}.chart-toolbar button{border-radius:5px;background:#182d3e;color:var(--muted);padding:7px 10px;font-size:12px}.chart-toolbar button.selected{background:#25464e;color:#9cecdf}.svg-wrap{width:100%;overflow:hidden}.distribution{display:block;width:100%;height:auto;min-height:210px}.distribution .gridline{stroke:#243e51;stroke-dasharray:3 5}.distribution text{fill:#8ba7b9;font:13px Consolas,monospace}.distribution .bar{fill:#377ba1;transition:y .3s,height .3s,fill .25s;stroke:transparent;stroke-width:2}.distribution .bar.critical{fill:#ff9569}.distribution .bar.observed{fill:#60dfd0}.distribution .bar-group{cursor:pointer}.distribution .bar-group:hover .bar,.distribution .bar-group:focus .bar{fill:#a8fff2;stroke:#bffff8}.distribution .bar-group:focus{outline:none}.distribution .obs-line{stroke:#d4faff;stroke-width:1.5;stroke-dasharray:4 4}.distribution .obs-dot{fill:#e7ffff}.distribution .xlabel{fill:#d4e6ec}.distribution .obs-text{fill:#d7ffff;font-weight:700}.chart-legend{display:flex;flex-wrap:wrap;gap:18px;color:var(--muted);font-size:12px;margin-top:-4px}.legend-item{display:flex;align-items:center;gap:7px}.legend-item i{width:10px;height:10px;background:#377ba1;border-radius:2px}.legend-item i.orange{background:#ff9569}.legend-item i.cyan{background:#60dfd0}.legend-item i.white{border:1px solid #e1ffff;background:none}.chart-foot{display:flex;justify-content:space-between;gap:12px;border-top:1px solid var(--line);padding-top:13px;margin-top:17px;font-size:13px;color:var(--muted)}.chart-foot strong{color:#beeae8}.metric-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:13px;margin-top:17px}.metric{background:#142739;border:1px solid #2c4354;border-radius:9px;padding:15px 17px}.metric>span{display:block;color:var(--muted);font-size:12px}.metric strong{display:block;font:26px/1.3 Consolas,monospace;color:var(--ink);margin:6px 0}.metric small{color:var(--muted);font-size:12px}.metric.emphasis{background:#173138;border-color:#326268}.metric.emphasis strong{color:var(--mint)}.metric .math{font-size:22px}.decision{border:1px solid #346967;background:#153536;padding:19px 22px;border-radius:9px;margin-top:17px;display:flex;gap:16px;align-items:start}.decision.reject{border-color:#88563f;background:#352920}.decision-icon{font:26px/1.3 Georgia,serif;color:var(--mint)}.decision.reject .decision-icon{color:var(--orange)}.decision h4{margin:0 0 5px;font-size:17px}.decision p{font-size:14px;color:#acc8ce;margin:0}.decision.reject p{color:#d7bfb0}.presets{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin:16px 0 0}.presets span{font-size:12px;color:var(--muted)}.presets button{padding:6px 10px;border:1px solid #355063;border-radius:5px;background:transparent;color:#bdd5e0;font-size:12px}.presets button:hover{background:#254450}.footnote{font-size:13px;color:#95b0c0;margin:18px 0}.footnote strong{color:var(--orange);font-weight:500}.accordion{margin-top:18px;padding:15px 20px;border:1px solid var(--line);border-radius:8px;background:#101e2d}.accordion summary{font-size:14px;cursor:pointer;color:#b8dce5}.accordion[open] summary{margin-bottom:16px}.accordion p,.accordion li{font-size:14px;color:var(--muted)}.accordion p:last-child{margin-bottom:0}.working{font:18px/1.8 Cambria,serif;color:#cef7f0!important;overflow-wrap:anywhere}.next-row{display:flex;justify-content:flex-end;margin-top:25px}.model-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}.hypothesis-card{padding:25px 28px;position:relative;overflow:hidden}.hypothesis-card::after{content:'H₀';position:absolute;right:16px;bottom:-28px;font:130px Georgia,serif;opacity:.035}.hypothesis-card.alt::after{content:'H₁'}.hypothesis-card .eyebrow{margin-bottom:15px}.hypothesis-card .math.big{font-size:38px;margin:0 0 13px}.hypothesis-card p:last-child{font-size:15px;color:#9fbbc9;margin:0}.hypothesis-card.alt{border-color:#3b6970;background:#102b36}.model-band{display:grid;grid-template-columns:1fr 1.4fr;gap:28px;padding:28px 0;margin:8px 0;border-bottom:1px solid var(--line)}.model-band p{color:var(--muted);font-size:14px}.model-band .math{color:#d8f6f5}.conditions{display:grid;grid-template-columns:1fr 1fr;gap:12px}.condition{border-left:2px solid #367780;padding:2px 15px}.condition strong{display:block;font-size:14px;margin-bottom:5px}.condition span{font-size:13px;color:var(--muted)}.logic-flow{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin:22px 0}.logic-flow>div{border-top:1px solid #356072;padding:15px 8px 0 0}.logic-flow b{color:#59cabc;font:12px Consolas,monospace}.logic-flow h4{font-size:16px}.logic-flow p{font-size:14px;color:var(--muted);margin:0}.direction-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-bottom:22px}.direction-card{text-align:left;color:var(--ink);border:1px solid #2a455b;border-radius:10px;background:#122538;padding:18px 20px}.direction-card.selected{background:#17393f;border-color:#69dacc;box-shadow:inset 0 0 24px #68dfd008}.direction-card .direction-icon{float:right;font-size:28px;color:#659eb6}.direction-card.selected .direction-icon{color:#75e7d6}.direction-card b{display:block;font-size:16px;margin-bottom:4px}.direction-card small{display:block;font-size:12px;color:#8ba7b9}.direction-card .math{display:block;font-size:24px;margin:10px 0 5px}.direction-card p{font-size:13px;color:#a0bac8;margin:0}.compare-bottom{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin-top:20px}.callout{border-left:3px solid #73bfe8;background:#122638;padding:17px 20px;font-size:14px;color:#b1cdd9}.callout h4{margin:0 0 6px}.callout p{margin:0}.callout.orange{border-color:var(--orange);background:#2b2522;color:#cbbeb2}.inline-controls{display:flex;align-items:center;gap:20px;flex-wrap:wrap;margin-bottom:18px}.inline-controls label{font-size:14px;color:#b3cdd9;display:flex;gap:10px;align-items:center}.inline-controls input{max-width:180px}.inline-controls output{font:22px Consolas,monospace;color:var(--mint)}.simulation-top{display:grid;grid-template-columns:1fr 1fr;gap:22px}.simulation-controls .control{margin-bottom:17px;padding-bottom:17px}.simulation-controls p{color:var(--muted);font-size:14px}.sim-progress{height:4px;margin:20px 0;background:#21394b;border-radius:4px;overflow:hidden}.sim-progress>div{height:100%;background:#68dfd0;transition:width .15s}.sim-map{display:grid;grid-template-columns:repeat(50,1fr);gap:3px;min-height:135px}.sim-dot{aspect-ratio:1;background:#274358;border-radius:1px}.sim-dot.rejected{background:#ff9569}.sim-map-caption{font-size:12px;color:var(--muted);margin:12px 0 0}.sim-numbers{display:grid;grid-template-columns:1fr 1fr;gap:15px;margin-top:20px}.sim-numbers b{display:block;font:29px Consolas,monospace;color:var(--mint)}.sim-numbers span{font-size:13px;color:var(--muted)}.quiz{margin-top:26px}.quiz h3{font-size:19px}.quiz-questions{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.quiz-item{padding:20px;border:1px solid var(--line);border-radius:10px;background:#101f2f}.quiz-item>p{font-size:15px;min-height:74px}.quiz-options{display:flex;gap:8px}.quiz-options button{background:#20384c;color:#bcd6e2;border:1px solid #38566b;border-radius:6px;padding:9px 14px;flex:1;font-size:14px}.quiz-options button.right{background:#174b49;border-color:#67d5bc;color:#baf7e8}.quiz-options button.wrong{background:#4a2c2b;border-color:#ce7a64;color:#ffcabc}.feedback{font-size:13px;color:#add0d2;margin:12px 0 0;min-height:43px}.glossary{display:grid;grid-template-columns:1fr 1fr;gap:0 25px}.glossary>div{padding:14px 0;border-bottom:1px solid var(--line)}.glossary dt{color:#bfdedc;font-size:14px}.glossary dd{font-size:13px;color:var(--muted);margin:4px 0 0}.source-links a{color:#79cbbf;text-decoration:underline;text-underline-offset:3px}.replay-result{margin-top:15px}.replay-result:empty{display:none}.teaching-note{font-size:13px!important;color:#82a3b5!important}.prob-table{width:100%;border-collapse:collapse;font-size:13px;text-align:left}.prob-table th,.prob-table td{padding:9px 10px;border-bottom:1px solid #2a4253}.prob-table th{color:#bce9e0}.prob-table td{color:#98b7c5}.prob-table tr.focus td{color:#ffb494}.live-formula{font-family:Cambria,"Times New Roman",serif;font-size:20px;color:#acebdd;margin:12px 0}.lesson-panel{scroll-margin-top:20px}.result-note{font-size:13px;color:#b8ccda;margin-top:12px}.metric strong.tight{font-size:20px}.progressive-step{color:var(--teal);font-size:12px}.step-number{font:16px Consolas,monospace;color:#557d95;padding-right:12px}.lesson-nav button[aria-current=step]{border-color:var(--teal)}.trial{font-size:12px}.brand-en{font-size:11px}.chart-toolbar button,.presets button,.eyebrow,.pill,.control-title{font-size:12px}.suit-buttons span{font-size:14px}.experiment-bottom,.game-status{font-size:14px}.legend-item,.chart-legend{font-size:13px}.course{font-size:12px}.chart-sub{font-size:14px}.controls .control small{font-size:13px}body{font-size:16px}
@media(max-width:1050px){.workspace{grid-template-columns:225px minmax(0,1fr);gap:18px}.chart-panel{padding:20px}.metric{padding:13px}.metric strong{font-size:23px}.chart-heading{flex-direction:column}.quiz-item>p{min-height:100px}}
@media(max-width:850px){.workspace{grid-template-columns:1fr}.controls{display:grid;grid-template-columns:1fr 1fr;gap:18px}.controls .control-title{grid-column:1/-1;margin-bottom:0}.controls .control{margin:0;padding:0 0 15px}.chart-heading{flex-direction:row}.model-band{grid-template-columns:1fr}.direction-cards{gap:9px}.direction-card{padding:14px}.direction-card .direction-icon{float:none}.compare-bottom,.simulation-top{grid-template-columns:1fr}.quiz-questions{grid-template-columns:1fr}.quiz-item>p{min-height:0}.quiz-options{max-width:300px}.feedback{min-height:0}.glossary{grid-template-columns:1fr}.chart-panel{padding:18px}.metric strong.tight{font-size:18px}.simulation-controls .control{margin-bottom:15px}.sim-map{min-height:90px}}
@media(max-width:520px){.model-grid{grid-template-columns:1fr}.hypothesis-card{padding:22px}.logic-flow{grid-template-columns:1fr;gap:10px}.logic-flow>div{padding:12px 0}.direction-cards{grid-template-columns:1fr}.direction-card .direction-icon{float:right}.direction-card .math{margin:5px 0}.direction-card{padding:13px 17px}.direction-card small{display:inline}.metric-grid{grid-template-columns:1fr 1fr}.metric-grid .metric:last-child{grid-column:1/-1}.metric-grid .metric:last-child strong{display:inline-block;margin-right:12px}.chart-foot{flex-direction:column;gap:4px}.chart-heading{flex-direction:column}.chart-toolbar{margin:4px 0 0}.distribution{min-height:165px}.conditions{gap:15px}.condition{padding-left:10px}.inline-controls{gap:8px}.inline-controls label{flex-wrap:wrap}.sim-map{gap:2px}.controls{padding:18px}.metric strong{font-size:24px}.chart-legend{gap:9px}.intro h1{font-size:30px}.section-heading{margin-bottom:17px}.suit-buttons button{font-size:30px}.course{display:none}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
.focused{padding-top:15px}.focused .intro{display:none}.focused .lesson-nav{margin-bottom:22px}.chart-sub{line-height:1.5}.distribution .obs-line,.distribution .obs-dot,.distribution .obs-text{pointer-events:none}
@media(max-width:850px){.lesson-nav{grid-template-columns:repeat(5,minmax(0,1fr));gap:6px;overflow:visible}.lesson-nav button{font-size:13px;white-space:normal;text-align:center;line-height:1.6;padding:12px 1px}.lesson-nav button span{display:block;margin:0 0 4px;font-size:12px}.focused{padding-top:0}.focused .lesson-nav{margin-bottom:20px}.chart-heading .math{font-size:17px}.distribution text{font-size:12px}}
@media(max-width:380px){.lesson-nav button{font-size:12px}.controls{gap:12px}.control label{font-size:13px}.control output{font-size:22px}}
@media(max-width:520px){.topbar{gap:10px}.brand{gap:10px}.brand-en{font-size:9px;letter-spacing:.12em;white-space:nowrap}.topbar .quiet{white-space:nowrap;flex-shrink:0;padding:8px 0 8px 12px}.lesson-nav button{font-size:13px;word-break:keep-all}.control label{gap:5px}.control output{flex-shrink:0}}
/* Tail probabilities: show the sum of the individual column heights. */
[hidden]{display:none!important}.chart-toolbar{flex-wrap:wrap}.chart-toolbar .sum-mode-button{border:1px solid #408e8c;color:#95eee1}.tail-sum{border-top:1px solid #315565;margin-top:20px;padding-top:19px}.sum-intro .eyebrow{font-size:11px}.sum-intro h4{font-size:17px;margin:5px 0}.sum-intro p{font-size:14px;color:#9ebbc8;margin:7px 0 14px}.sum-actions{display:flex;align-items:center;flex-wrap:wrap;gap:8px}.sum-actions button{border:1px solid #35566a;background:#192f42;color:#d1e7ed;border-radius:6px;padding:8px 13px;font-size:14px;min-height:40px}.sum-actions .primary{background:#6ce1d3;color:#0b2932;border-color:#6ce1d3;padding-inline:19px}.sum-stage{margin:18px 0;display:flex;align-items:center;justify-content:space-between;gap:18px}.sum-stage>div>span{font-size:13px;color:#8eafbf}.sum-stage p{font-size:19px;color:#c3eee7;margin:5px 0 0}.sum-value{text-align:right;flex-shrink:0}.sum-value strong{display:block;font:32px/1.35 Consolas,monospace;color:#87edd9}.sum-equation{background:#09212d;border-left:3px solid #69cfbf;color:#c6ebe4;padding:12px 15px;font-size:18px;line-height:1.75;overflow-wrap:anywhere}.sum-terms{position:relative;display:grid;grid-template-columns:repeat(auto-fit,minmax(100px,1fr));gap:8px;max-height:178px;overflow:auto;margin-top:15px;padding:2px 4px 2px 0;scrollbar-color:#3e6c79 #112431}.sum-term{background:#142737;border:1px solid #2a4252;border-radius:6px;padding:8px 9px;opacity:.6}.sum-term span{display:block;font:13px Cambria,serif;color:#a7bdc8}.sum-term b{display:block;font:14px/1.5 Consolas,monospace;color:#bfd9e0}.sum-term small{font-size:11px;color:#7594a5}.sum-term.added{border-top:3px solid var(--term-color);padding-top:6px;opacity:1}.sum-term.latest{background:#214449;border-color:#e4eab6;box-shadow:0 0 12px #adeac510}.sum-term.added small{color:#97dccb}.sum-verdict{margin:17px 0 0;padding:12px 15px;background:#193040;border-radius:6px;color:#adcbd7;font-size:14px}.sum-verdict.within{background:#173d3d;color:#b9eee4;border:1px solid #3b7e70}.sum-verdict.over{background:#3d2a24;color:#f2c8b1;border:1px solid #926044}.sum-compare{display:flex;align-items:center;flex-wrap:wrap;gap:8px;margin-top:15px}.sum-compare span{color:#94b1be;font-size:12px;margin-right:6px}.sum-compare button{background:none;border:1px solid #496a7a;border-radius:5px;padding:6px 10px;font-size:13px;color:#b8e2df}.sum-compare button:hover{background:#214550}.sum-distribution{min-height:250px}.sum-distribution .bar-group:hover rect:last-of-type{stroke:#ecf5c3;stroke-width:1}.sum-segment{animation:sum-reveal .35s ease-out}@keyframes sum-reveal{from{opacity:.45}to{opacity:1}}@media(max-width:600px){.sum-stage{align-items:start;gap:10px}.sum-stage p{font-size:17px}.sum-value strong{font-size:25px}.sum-stage>div>span{font-size:12px}.sum-actions{gap:6px}.sum-actions button{font-size:13px;padding:8px 10px}.sum-actions .primary{padding-inline:12px}.sum-equation{font-size:16px}.sum-terms{grid-template-columns:repeat(3,minmax(0,1fr));max-height:165px;gap:5px}.sum-term{padding:7px 5px}.sum-term b{font-size:12px}.sum-intro h4{font-size:16px}.sum-compare span{width:100%}.chart-toolbar{gap:5px}.chart-toolbar button{font-size:12px}.sum-value{max-width:43%}}
.sum-numeric{font-size:16px;color:#8cc6c0;margin-top:6px}.sum-segment{animation:none}@media(max-width:600px){.sum-numeric{font-size:14px}}
/* In-place accumulation on the original plot. */
.accumulating .bar{transition:none}.accumulating .bar.sum-transferred{fill:#255167;fill-opacity:.13;stroke:#63a5b5;stroke-opacity:.35;stroke-width:.8}.accumulating .bar.sum-source{fill-opacity:.18;stroke:#fff1b7;stroke-width:1;stroke-opacity:.85}.sum-overlay{isolation:isolate}.distribution .sum-trail{fill:none;stroke:#84d8d0;stroke-width:1.15;stroke-dasharray:4 6;stroke-opacity:.22}.distribution .sum-trail.current{stroke:#b4f1dc;stroke-opacity:.75;stroke-width:1.5}.distribution .sum-alpha{stroke:#ff9569;stroke-width:1.5;stroke-dasharray:5 4}.distribution .sum-alpha-label{fill:#ffba97;font-weight:600;font-size:12px}.distribution .sum-total-label{fill:#d0fff1;font-size:13px;font-weight:700;paint-order:stroke;stroke:#102331;stroke-width:4;stroke-linejoin:round}.sum-flying{will-change:transform;filter:drop-shadow(0 0 4px #9de9d74d)}.sum-settled{animation:none;transition:none}.tail-sum .sum-intro{display:none}.tail-sum{padding-top:16px;margin-top:16px}.sum-actions{margin-bottom:2px}@media(max-width:600px){.distribution .sum-total-label{font-size:12px}.sum-flying{filter:none}}

/* Selected tail and adjustable risk, with a taller shared plot. */
.workspace{grid-template-columns:280px minmax(0,1fr)}.controls .control{padding-bottom:18px;margin-bottom:18px}.tail-link{margin-top:14px;padding:13px 12px;border:1px solid #32636b;background:#102f3a;border-radius:9px}.tail-link-event{display:flex;align-items:center;justify-content:space-between;gap:8px}.tail-link-event span{font-size:12px;color:#9ebbc8}.tail-link-event strong{font-size:26px;color:#b9fff1}.tail-link small{margin-top:3px;font-size:12px!important}.tail-link .primary{width:100%;padding:9px 6px;margin-top:12px;font-size:13px}.tail-linked-sum{border-top:1px solid #2d5663;margin-top:13px;padding-top:10px}.tail-linked-sum span{display:block;color:#99bfc9;font-size:12px}.tail-linked-sum strong{display:block;font:23px/1.5 Consolas,monospace;color:#bcfbed;overflow-wrap:anywhere}.alpha-slider{margin-top:13px}.control #alphaOut{font-size:25px}.chart-foot>span:empty{display:none}.chart-sub{font-size:12px}.accumulating .obs-line,.accumulating .obs-dot,.accumulating .obs-text{opacity:0}.chart-panel{padding-bottom:19px}.sum-stage{margin:14px 0}.sum-verdict{margin-top:12px}.sum-compare{display:none}.chart-legend .legend-item:not(:first-child){display:none}.chart-legend .legend-item.is-relevant{display:flex}.tail-link .primary:active{transform:translateY(1px)}
@media(max-width:1050px){.workspace{grid-template-columns:250px minmax(0,1fr)}}@media(max-width:850px){.workspace{grid-template-columns:1fr}.controls{grid-template-columns:1fr 1fr;align-items:start}.controls .control{margin:0}.tail-link{margin-top:10px}.chart-sub{font-size:12px}}@media(max-width:520px){.controls{grid-template-columns:1fr}.controls .control{padding-bottom:16px}.tail-link-event strong{font-size:28px}.tail-linked-sum{display:flex;align-items:center;justify-content:space-between;gap:10px}.tail-link .primary{font-size:14px}.chart-panel{padding-inline:12px}.sum-stage p{font-size:16px}}

/* Compact classroom controls and a shared animation toolbar. */
.classroom-focused .topbar{height:64px}.classroom-focused .course{display:none}.focused{padding-top:10px}.focused .lesson-nav{margin-bottom:14px;gap:12px}.focused .lesson-nav button{padding:9px 0}.focused .section-heading{margin-bottom:12px}.focused .section-heading h2{font-size:21px}.focused .section-heading .eyebrow,.focused .section-heading .pill{display:none}.workspace{grid-template-columns:260px minmax(0,1fr);gap:18px;align-items:start}.controls{padding:16px 18px;position:sticky;top:12px}.controls .control{padding-bottom:11px;margin-bottom:11px}.controls .control:last-child{padding-bottom:0;margin:0}.controls label,.controls .control-label{margin-bottom:6px;font-size:14px}.controls output,.controls #alphaOut{font-size:23px}.controls .range-ends{font-size:11px;line-height:1.2}.controls input[type=range]{height:18px;margin:0}.controls .alpha-slider{margin-top:7px!important}.controls .segmented button{padding:5px 7px;font-size:13px}.controls select{padding:7px 9px;font-size:13px}.controls .tail-range-control .control-label{margin:0}.controls #tailRange{font:23px/1 Consolas,monospace;color:var(--teal)}.chart-panel{padding:14px 18px}.chart-heading{display:block}.chart-heading h3{font-size:17px}.chart-controls{display:flex;align-items:center;justify-content:space-between;gap:8px;margin:10px 0 4px;position:sticky;top:0;background:#101e2e;z-index:2;padding:4px 0}.chart-toolbar{margin:0;gap:5px}.chart-toolbar button{min-height:34px;padding:6px 12px;font-size:13px}.chart-controls .sum-actions{gap:6px;margin:0;flex-wrap:nowrap}.chart-controls .sum-actions button{min-height:34px;padding:5px 12px;font-size:13px}.chart-controls .sum-actions .primary{padding-inline:16px;min-width:94px}.chart-foot{margin-top:3px;padding-top:7px;font-size:12px}.tail-sum{margin:9px 0 0;padding:8px 0 0}.sum-stage{margin:0;align-items:center;gap:10px}.sum-stage p{font-size:16px;margin-top:2px}.sum-stage>div>span{font-size:12px}.sum-value strong{font-size:26px}.sum-value>span{font-size:12px}.sum-verdict{padding:7px 10px;font-size:12px;margin:7px 0 0;line-height:1.55}.sum-details{margin-top:8px;font-size:12px;color:#90b8c5}.sum-details summary{cursor:pointer}.sum-details[open] summary{margin-bottom:8px}.sum-equation{font-size:15px;padding:8px 11px}.sum-numeric{font-size:13px}.metric-grid{gap:10px;margin-top:10px}.metric{padding:10px 12px}.metric strong{font-size:23px;margin:3px 0}.decision{margin-top:10px;padding:12px 15px}.presets{display:none}.distribution{min-height:0}.distribution text{font-size:12px}
@media(max-width:1050px){.workspace{grid-template-columns:245px minmax(0,1fr);gap:14px}.controls{padding-inline:14px}.chart-panel{padding-inline:14px}}@media(max-width:850px){.workspace{grid-template-columns:1fr}.controls{position:static;display:grid;grid-template-columns:1fr 1fr;gap:10px 18px}.controls .control{margin:0;padding-bottom:8px}.controls .tail-range-control{grid-column:2;grid-row:2;align-self:start}.controls .control:nth-child(4){grid-column:1;grid-row:2 / span 2}.controls .control:last-child{grid-row:3}.focused .lesson-nav{gap:5px}.focused .lesson-nav button{font-size:12px;padding:8px 1px}.focused .lesson-nav button span{display:none}.focused .section-heading h2{font-size:18px}.chart-controls{top:0}}@media(max-width:520px){.classroom-focused .topbar{height:58px}.focused{padding-top:6px}.controls{grid-template-columns:1fr 1fr;padding:13px 14px;gap:10px 12px}.controls label,.controls .control-label{font-size:12px}.controls output,.controls #alphaOut,.controls #tailRange{font-size:21px}.controls .control:last-child select{font-size:12px;padding-inline:4px}.chart-panel{padding:12px 10px}.chart-heading h3{font-size:15px}.chart-toolbar button{padding-inline:8px;font-size:12px}.chart-controls .sum-actions{gap:4px}.chart-controls .sum-actions button{padding-inline:8px;font-size:12px}.chart-controls .sum-actions .primary{padding-inline:10px;min-width:82px}.sum-stage p{font-size:14px}.sum-value strong{font-size:22px}.sum-verdict{font-size:12px}}

.controls input[type=range]{display:block}.controls label,.controls .control-label{line-height:1.35}
@media(max-height:700px) and (min-width:851px){.classroom-focused .topbar{height:56px}.focused{padding-top:6px}.focused .lesson-nav{margin-bottom:10px}.focused .lesson-nav button{padding:6px 0;font-size:13px}.focused .section-heading{margin-bottom:8px}.focused .section-heading h2{font-size:19px}.controls{padding:13px 16px}.controls .control{padding-bottom:8px;margin-bottom:8px}.controls label,.controls .control-label{font-size:13px;margin-bottom:4px}.controls output,.controls #alphaOut,.controls #tailRange{font-size:21px}.controls .segmented button{padding:4px 7px;min-height:30px}.controls select{padding:5px 8px}.controls .alpha-slider{margin-top:5px!important}.chart-panel{padding-top:11px}.chart-controls{margin-top:6px}.chart-heading h3{font-size:16px}}

/* Selected point probability, one restore action and continuous speed control. */
.distribution .obs-text{font-size:12px;paint-order:stroke;stroke:#101e2e;stroke-width:4px;stroke-linejoin:round}.accumulating .obs-line{opacity:.45}.accumulating .obs-dot,.accumulating .obs-text{opacity:1}.speed-control{display:flex;align-items:center;gap:9px;padding-left:6px;animation:speed-appear .22s ease-out}.speed-control label{display:flex;align-items:center;gap:7px;white-space:nowrap;font-size:12px;color:#a7cbd5}.speed-control output{color:#b6f5e8;font:14px Consolas,monospace;min-width:33px}.speed-control input{width:115px;height:20px;margin:0;accent-color:var(--teal)}.chart-controls .sum-actions{gap:9px;flex-wrap:wrap;justify-content:flex-end}.controls{display:flex;flex-direction:column;justify-content:space-between;padding:20px 18px}.controls .control{flex:0 0 auto;width:100%;margin:0;padding-bottom:14px}.controls label,.controls .control-label{margin-bottom:9px}.controls input[type=range]{height:20px}.controls .segmented button{padding-block:7px}.controls.toolbar-compact{padding:13px 16px}.controls.toolbar-compact .control{padding-bottom:8px}.controls.toolbar-compact .control:last-child{padding-bottom:0}.controls.toolbar-compact label,.controls.toolbar-compact .control-label{font-size:13px;margin-bottom:4px}.controls.toolbar-compact output,.controls.toolbar-compact #alphaOut,.controls.toolbar-compact #tailRange{font-size:21px}.controls.toolbar-compact input[type=range]{height:18px}.controls.toolbar-compact .segmented button{padding-block:4px}.controls.toolbar-compact select{padding-block:5px}.controls.toolbar-compact .alpha-slider{margin-top:5px!important}@keyframes speed-appear{from{opacity:0;transform:translateX(6px)}to{opacity:1;transform:translateX(0)}}
@media(max-width:850px){.controls{display:grid;padding:14px 16px;gap:10px 18px}.controls .control{padding-bottom:8px}.controls label,.controls .control-label{margin-bottom:6px}.controls .segmented button{padding-block:5px}.chart-controls{flex-wrap:wrap}.chart-controls .sum-actions{margin-left:auto}.speed-control{padding-left:0;gap:6px}.speed-control input{width:95px}}@media(max-width:520px){.controls{padding:13px 14px;gap:10px 12px}.chart-controls{gap:4px}.speed-control{flex-basis:100%;justify-content:flex-end;padding-top:3px}.speed-control input{width:130px}.chart-controls .sum-actions:has(.speed-control:not([hidden])){flex-basis:100%;justify-content:space-between}.chart-controls .sum-actions:has(.speed-control:not([hidden])) .speed-control{flex-basis:auto}.distribution .obs-text{font-size:11px}}

@media(max-width:520px){.speed-control input{width:110px}}