/* Learning layer, paper edition: teaching-model diagrams, disclosures, worksheets as ruled index
   cards, the guided/explore toolbar. Loads after deck.css and launch.css; tokens come from paper.css. */
body[data-deck]{--deck-bottom:128px}
.slide{scrollbar-width:thin;scrollbar-color:rgba(10,11,13,.35) transparent;scroll-padding-block:90px 150px}
.slide::-webkit-scrollbar{width:6px}
.slide::-webkit-scrollbar-thumb{background:rgba(10,11,13,.35);border-radius:8px}
/* the deck keeps content static; only the sheet itself enters (deck.css) */
.slide [data-rise],.slide .anim-words .hw{opacity:1;transform:none;animation:none!important}
.slide .eyebrow__hint{color:var(--text-3)}

/* ---------- disclosures: native details, animated where supported ---------- */
.learn-detail{margin:20px 0 0;max-width:72ch;color:inherit;border-top:1.5px dashed rgba(10,11,13,.28);padding-top:6px;interpolate-size:allow-keywords}
.learn-detail>summary{list-style:none;display:flex;align-items:center;gap:12px;min-height:48px;padding:8px 4px;cursor:pointer;border-radius:10px;
  font-family:var(--font-display);font-weight:700;font-size:16.5px;line-height:1.3;color:var(--cobalt-deep);-webkit-tap-highlight-color:transparent}
.learn-detail>summary::-webkit-details-marker{display:none}
.learn-detail>summary::before{content:"";flex:none;width:28px;height:28px;border:var(--line) solid var(--ink);border-radius:50%;
  background:linear-gradient(var(--ink),var(--ink)) center/11px 2.5px no-repeat,linear-gradient(var(--ink),var(--ink)) center/2.5px 11px no-repeat,var(--pale-2);
  box-shadow:2px 2px 0 var(--ink);transition:transform var(--t) var(--ease),background-color var(--t) var(--ease)}
.learn-detail>summary:hover{background:var(--pale-2)}
.learn-detail[open]>summary::before{transform:rotate(180deg);background:linear-gradient(#fff,#fff) center/11px 2.5px no-repeat,var(--cobalt)}
.learn-detail::details-content{block-size:0;overflow:hidden;transition:block-size .3s var(--ease),content-visibility .3s allow-discrete}
.learn-detail[open]::details-content{block-size:auto}
.learn-detail__body{margin:4px 0 6px 13px;padding:2px 0 6px 25px;border-left:3px solid var(--pale);font-size:16.5px;line-height:1.65;color:var(--text-2)}
.learn-detail__body p{margin:10px 0;max-width:68ch;font-size:16.5px;line-height:1.65;color:inherit}
.learn-detail__body p.body{margin-top:10px}
.slide--blue:not(.slide--reveal) .learn-detail,.slide--dark .learn-detail{border-color:rgba(255,255,255,.4)}
.slide--blue:not(.slide--reveal) .learn-detail>summary,.slide--dark .learn-detail>summary{color:#fff}
.slide--blue:not(.slide--reveal) .learn-detail>summary:hover,.slide--dark .learn-detail>summary:hover{background:rgba(255,255,255,.12)}
.slide--blue:not(.slide--reveal) .learn-detail__body,.slide--dark .learn-detail__body{color:rgba(255,255,255,.9)}
.verdict .learn-detail{margin-top:12px}

/* ---------- teaching models: paper diagrams with ink lines ---------- */
.model-summary{font-size:clamp(18px,1.8vw,21px);line-height:1.5;color:var(--text-2);max-width:62ch;margin:18px 0 24px;text-wrap:pretty}
.model,.formula-card{position:relative;margin:24px 0;padding:clamp(18px,3vw,30px);color:var(--text);border:var(--line) solid var(--ink);border-radius:var(--r);
  background:radial-gradient(rgba(10,11,13,.13) 1px,transparent 1.3px) 0 0/18px 18px,var(--paper)}
.model figcaption,.formula-card figcaption{width:fit-content;max-width:100%;margin:0 0 20px;font-family:var(--font-body);font-weight:700;font-size:12px;line-height:1.35;letter-spacing:.1em;text-transform:uppercase;color:var(--ink);
  background:var(--sheet);border:1.5px solid var(--ink);border-radius:6px;padding:5px 10px;transform:rotate(-1deg)}
.model-cells{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}
.model-cell{position:relative;min-width:0;padding:18px 16px 18px;background:var(--sheet);border:var(--line) solid var(--ink);border-radius:14px;box-shadow:3px 3px 0 var(--ink)}
.model-cell h3{font-family:var(--font-display);font-weight:700;font-size:20px;line-height:1.18;letter-spacing:-.01em;color:var(--ink);margin:12px 0 8px;overflow-wrap:break-word}
.model-cell p{font-size:15px;line-height:1.55;color:var(--text-2);margin:0}
.model-index{display:inline-grid;place-items:center;width:36px;height:36px;border-radius:50%;border:var(--line) solid var(--ink);background:var(--cobalt);color:#fff;
  font-family:var(--font-display);font-weight:800;font-size:14px;line-height:1}
.model-cell:nth-child(even) .model-index{background:var(--pale);color:var(--ink)}
/* connectors: inked arrows in small sheet discs between cells */
.model--path .model-cell:not(:last-child)::after,.model--product .model-cell:not(:last-child)::after{position:absolute;right:-22px;top:28px;z-index:2;display:grid;place-items:center;width:28px;height:28px;
  border:var(--line) solid var(--ink);border-radius:50%;background:var(--sheet);color:var(--ink);font-family:var(--font-display);font-weight:800;font-size:16px;line-height:1}
.model--path .model-cell:not(:last-child)::after{content:"\2192"}
.model--product .model-cell:not(:last-child)::after{content:"\00D7";top:50%;margin-top:-14px;font-size:18px}
.model--path .model-cells:has(li:nth-child(4)){grid-template-columns:repeat(4,minmax(0,1fr))}
.model--leverage .model-cells,.model--matrix .model-cells,.model--compare .model-cells{grid-template-columns:repeat(2,minmax(0,1fr))}
.model--matrix .model-cell:nth-child(odd){box-shadow:inset 7px 0 0 var(--cobalt),3px 3px 0 var(--ink);padding-left:22px}
.model--matrix .model-cell:nth-child(even){box-shadow:inset 7px 0 0 var(--gold),3px 3px 0 var(--ink);padding-left:22px}
.model--checklist .model-cells{grid-template-columns:1fr;gap:12px}
.model--checklist .model-cell{display:grid;grid-template-columns:36px 1fr 1.4fr;gap:16px;align-items:center;padding:14px 16px}
.model--checklist h3{margin:0;font-size:19px}
.model--stack .model-cells{grid-template-columns:1fr;max-width:700px;margin:auto}
.model--stack .model-cell{box-shadow:inset 7px 0 0 var(--cobalt),3px 3px 0 var(--ink);padding-left:24px}
.model--funnel .model-cells,.model--ladder .model-cells{display:flex;flex-direction:column;align-items:center}
.model--funnel .model-cell{width:100%;text-align:center}
.model--funnel .model-cell:nth-child(2){width:86%}
.model--funnel .model-cell:nth-child(3){width:72%;background:var(--pale-2)}
.model--ladder .model-cell{width:75%;align-self:flex-start}
.model--ladder .model-cell:nth-child(2){align-self:center}
.model--ladder .model-cell:nth-child(3){align-self:flex-end;background:var(--pale-2)}
.model-note{font-size:13.5px!important;line-height:1.6!important;color:var(--text-3)!important;margin:18px 0 0!important;max-width:80ch}
.fanout{margin-top:24px;padding-top:22px;border-top:1.5px dashed rgba(10,11,13,.3);display:flex;flex-direction:column;align-items:center;gap:10px;font-size:16px;color:var(--text)}
.fanout>span:first-child{font-family:var(--font-display);font-weight:700}
.fanout>span[aria-hidden]{font-family:var(--font-display);font-weight:800;font-size:20px;line-height:1;color:var(--ink)}
.fanout>strong{padding:11px 24px;border:var(--line) solid var(--ink);border-radius:14px;background:var(--cobalt);color:#fff;font-family:var(--font-display);font-weight:700;box-shadow:3px 3px 0 var(--ink)}
.fanout>div{display:flex;flex-wrap:wrap;justify-content:center;gap:10px;border-top:var(--line) solid var(--ink);padding-top:14px;margin-top:4px}
.fanout>div span{background:var(--sheet);border:1.5px solid var(--ink);border-radius:var(--r-pill);padding:7px 14px;font-weight:600;font-size:15px}
.fanout p{font-size:14px;line-height:1.5;color:var(--text-3);text-align:center;margin:0;max-width:60ch}

/* the value equation */
.formula{display:flex;align-items:center;gap:24px;margin:18px 0 22px}
.formula-result{display:flex;gap:12px;white-space:nowrap;font-family:var(--font-display);font-weight:800;font-size:34px;letter-spacing:-.02em;color:var(--ink)}
.formula-result span{color:var(--cobalt-deep)}
.formula-fraction{flex:1;min-width:0;background:var(--sheet);border:var(--line) solid var(--ink);border-radius:14px;box-shadow:3px 3px 0 var(--ink);padding:4px 12px}
.formula-pair{display:grid;grid-template-columns:1fr 24px 1fr;gap:10px;text-align:center;padding:14px 0;align-items:center}
.formula-pair:first-child{border-bottom:3px solid var(--ink)}
.formula-term{font-family:var(--font-display);font-weight:700;font-size:clamp(17px,2vw,24px);line-height:1.15;color:var(--ink)}
.formula-term small{display:table;margin:8px auto 0;font-family:var(--font-body);font-weight:700;font-size:12px;letter-spacing:.03em;color:var(--ok);background:var(--ok-pale);border-radius:999px;padding:2px 8px}
.formula-pair:last-child small{color:var(--gold-deep);background:var(--gold-pale)}
.formula-times{font-family:var(--font-display);font-size:24px;color:var(--text-3)}
.formula-card>p{font-size:16px;line-height:1.5}
.cost-lens{margin-top:22px;padding:16px 18px;background:var(--pale-2);border:var(--line) solid var(--ink);border-radius:14px}
.cost-lens>strong{font-family:var(--font-display);font-weight:700;font-size:16px;color:var(--ink)}
.cost-lens__items{display:flex;gap:10px;margin:12px 0 4px;flex-wrap:wrap}
.cost-lens__items span{padding:8px 16px;background:var(--sheet);border:var(--line) solid var(--ink);border-radius:var(--r-pill);font-family:var(--font-display);font-weight:700;font-size:16px;box-shadow:2px 2px 0 var(--ink)}
.cost-lens p{font-size:15px;line-height:1.6;margin:8px 0 0;color:var(--text-2)}
.cost-lens .learn-detail{border-color:rgba(10,11,13,.25)}

/* comparison of two offers */
.comparison{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:22px}
.comparison article{border:var(--line) solid var(--ink);border-radius:var(--r);padding:20px;background:var(--sheet);color:var(--text);box-shadow:3px 3px 0 var(--ink)}
.comparison article:last-child{background:var(--pale-2);box-shadow:5px 5px 0 var(--cobalt)}
.comparison h3{font-family:var(--font-display);font-weight:800;font-size:23px;line-height:1.1;color:var(--ink);margin:0 0 6px}
.comparison dl{margin:0}
.comparison dt{margin-top:14px;font-weight:700;font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--text-3)}
.comparison dd{margin:4px 0 0;padding-bottom:10px;border-bottom:1.5px dashed rgba(10,11,13,.18);font-size:16px;line-height:1.4}
.comparison dd:last-child{border-bottom:0;padding-bottom:0}

/* ---------- labs: value-equation dials, delta compare ---------- */
.veq-lab,.delta-lab{margin-top:22px;padding:clamp(18px,3vw,26px);border:var(--line) solid var(--ink);border-radius:var(--r);background:var(--paper-2);color:var(--text);box-shadow:var(--sh)}
.veq-lab h3,.delta-lab h3{margin:0 0 8px;font-family:var(--font-display);font-weight:800;font-size:23px;letter-spacing:-.01em;color:var(--ink)}
.veq-lab>p,.delta-lab>p{font-size:15.5px;line-height:1.5;color:var(--text-2);margin:0 0 16px}
.lab-controls{display:grid;grid-template-columns:1fr 1fr;gap:12px 22px}
.lab-controls label{display:block;font-family:var(--font-display);font-weight:700;font-size:16px;line-height:1.4;color:var(--ink)}
.lab-controls output{float:right;min-width:34px;text-align:center;background:var(--sheet);border:1.5px solid var(--ink);border-radius:8px;padding:0 7px;font-variant-numeric:tabular-nums}
/* shared paper slider: a 44px tall hit area with an inked track */
.lab-controls input[type=range],.est__range{display:block;width:100%;height:44px;margin:4px 0;padding:0;appearance:none;-webkit-appearance:none;background:transparent;border:0;cursor:pointer;touch-action:pan-y}
.lab-controls input[type=range]::-webkit-slider-runnable-track,.est__range::-webkit-slider-runnable-track{height:14px;border-radius:999px;background:var(--pale-2);border:var(--line) solid var(--ink)}
.lab-controls input[type=range]::-moz-range-track,.est__range::-moz-range-track{height:14px;border-radius:999px;background:var(--pale-2);border:var(--line) solid var(--ink)}
.lab-controls input[type=range]::-moz-range-progress{height:14px;border-radius:999px;background:var(--pale)}
.lab-controls input[type=range]::-webkit-slider-thumb,.est__range::-webkit-slider-thumb{-webkit-appearance:none;appearance:none;width:30px;height:30px;margin-top:-10px;border-radius:50%;background:var(--cobalt);border:var(--line-strong) solid var(--ink);box-shadow:2px 2px 0 var(--ink);cursor:grab}
.lab-controls input[type=range]::-moz-range-thumb,.est__range::-moz-range-thumb{width:26px;height:26px;border-radius:50%;background:var(--cobalt);border:var(--line-strong) solid var(--ink);box-shadow:2px 2px 0 var(--ink);cursor:grab}
.lab-controls input[type=range]:focus-visible,.est__range:focus-visible{outline:3px solid var(--focus);outline-offset:2px;border-radius:10px}
.est__range:disabled{cursor:default}
.est__range:disabled::-webkit-slider-runnable-track{background:var(--paper-2)}
.est__range:disabled::-webkit-slider-thumb{background:var(--sheet);cursor:default}
.est__range:disabled::-moz-range-thumb{background:var(--sheet);cursor:default}
.est__trackwrap{padding:0}
.est__marker{top:5px}
.lab-result{margin-top:16px;padding:16px 18px;background:var(--ink);color:var(--sheet);border:var(--line) solid var(--ink);border-radius:14px;box-shadow:4px 4px 0 var(--cobalt);font-size:16.5px;line-height:1.5}
.lab-result strong{display:inline-block;margin:2px 0;font-family:var(--font-display);font-weight:800;font-size:34px;line-height:1.1;color:var(--pale);font-variant-numeric:tabular-nums}
.lab-result span{color:#C9CEDB}

/* ---------- buttons of the learning layer ---------- */
.worksheet button,.lab-reset,.lesson-complete,.mode-toggle{position:relative;display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:9px 16px;
  border:var(--line) solid var(--ink);border-radius:12px;background:var(--sheet);color:var(--ink);cursor:pointer;box-shadow:3px 3px 0 var(--ink);
  font-family:var(--font-display);font-weight:700;font-size:15px;line-height:1.15;text-align:center;-webkit-tap-highlight-color:transparent;touch-action:manipulation;
  transition:transform var(--t-fast) var(--ease),box-shadow var(--t-fast) var(--ease),background var(--t) var(--ease),color var(--t) var(--ease)}
.worksheet button:hover,.lab-reset:hover,.lesson-complete:hover,.mode-toggle:hover{transform:translate(-1px,-2px);box-shadow:4px 4px 0 var(--ink)}
.worksheet button:active,.lab-reset:active,.lesson-complete:active,.mode-toggle:active{transform:translate(2px,2px);box-shadow:1px 1px 0 var(--ink);transition-duration:60ms}
.worksheet [data-export-notes],.lesson-complete{background:var(--cobalt);color:#fff;border-width:var(--line-strong)}
.worksheet [data-export-notes]:hover,.lesson-complete:hover{background:#0a4ef0}
.slide--blue .lesson-complete{background:var(--gold);color:var(--ink)}
.lab-reset{margin-top:14px}
.mode-toggle[aria-pressed=true]{background:var(--pale-2)}
.lesson-skip{display:inline-flex;align-items:center;margin-top:18px;min-height:44px;padding:0 2px;border:0;background:none;color:var(--cobalt-deep);cursor:pointer;
  font-family:var(--font-display);font-weight:700;font-size:15.5px;text-decoration:underline;text-decoration-thickness:2px;text-underline-offset:4px;text-decoration-color:color-mix(in srgb,var(--cobalt) 45%,transparent)}
.lesson-skip:hover{text-decoration-color:var(--cobalt)}
.lesson-progress-note{font-size:14.5px;line-height:1.5;margin:20px 0 12px;max-width:52ch}
.slide--blue .lesson-progress-note{color:rgba(255,255,255,.85)}

/* ---------- worksheet: a ruled index card ---------- */
.worksheet{position:relative;margin-top:30px;padding:clamp(22px,3.4vw,34px) clamp(18px,3vw,32px) clamp(20px,3vw,28px);color:var(--text);
  border:var(--line) solid var(--ink);border-radius:14px;box-shadow:var(--sh);transform:rotate(-.3deg);
  background:linear-gradient(rgba(196,52,58,.45),rgba(196,52,58,.45)) 0 clamp(70px,8vw,80px)/100% 2px no-repeat,
    repeating-linear-gradient(to bottom,transparent 0 31px,rgba(0,85,254,.14) 31px 32px) 0 clamp(70px,8vw,80px)/100% 100% no-repeat,var(--sheet)}
.worksheet::before{content:"";position:absolute;top:-14px;right:34px;width:96px;height:28px;transform:rotate(4deg);background:rgba(191,211,255,.85);box-shadow:0 1px 1px rgba(10,11,13,.12);
  clip-path:polygon(3% 0,97% 6%,100% 30%,97% 52%,100% 78%,96% 100%,4% 94%,0 72%,3% 48%,0 22%);pointer-events:none}
.worksheet h3{margin:0 0 6px;font-family:var(--font-display);font-weight:800;font-size:clamp(24px,2.4vw,30px);letter-spacing:-.02em;line-height:1.05;color:var(--ink)}
.worksheet__privacy{display:flex;gap:8px;align-items:flex-start;font-size:13.5px;line-height:1.5;color:var(--text-3);margin:16px 0 8px;max-width:70ch}
.worksheet>label{display:grid;gap:8px;margin-top:20px;font-family:var(--font-display);font-weight:700;font-size:16.5px;line-height:1.35;color:var(--ink)}
.worksheet textarea{display:block;width:100%;resize:vertical;min-height:88px;max-height:420px;margin:0;padding:12px 14px;
  font:400 16px/1.55 var(--font-body);color:var(--text);background:var(--sheet);border:var(--line) solid var(--ink);border-radius:12px;
  box-shadow:inset 2px 2px 0 rgba(10,11,13,.06);transition:box-shadow var(--t) var(--ease),border-color var(--t) var(--ease)}
.worksheet textarea::placeholder{color:#767B88}
.worksheet textarea:focus{outline:none;border-color:var(--cobalt);box-shadow:0 0 0 3px var(--pale),3px 3px 0 var(--cobalt)}
.worksheet textarea:focus-visible{outline:none}
.worksheet textarea:user-invalid{border-color:var(--bad);box-shadow:0 0 0 3px var(--bad-pale)}
.worksheet__actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:22px}
.worksheet__status{min-height:22px;margin:14px 0 0;font-size:14.5px;line-height:1.45;color:var(--text-2)}
.worksheet__status:not(:empty){display:flex;flex-wrap:wrap;gap:6px 8px;align-items:center;width:fit-content;max-width:100%;padding:8px 12px;border:var(--line) solid var(--ink);border-radius:12px;background:var(--pale-2);box-shadow:2px 2px 0 var(--ink)}
.worksheet__status[data-state=ok]{background:var(--ok-pale)}
.worksheet__status[data-state=ok]::before{content:"\2713";display:grid;place-items:center;width:20px;height:20px;border-radius:50%;background:var(--ok);color:#fff;font-weight:800;font-size:12px;border:1.5px solid var(--ink)}
.worksheet__status[data-state=error]{background:var(--bad-pale)}
.worksheet__status[data-state=error]::before{content:"!";display:grid;place-items:center;width:20px;height:20px;border-radius:50%;background:var(--bad);color:#fff;font-weight:800;font-size:12px;border:1.5px solid var(--ink)}
.worksheet__status a{color:var(--cobalt-deep);font-weight:700;text-decoration:underline;text-underline-offset:3px}
.worksheet .takeaway-preview textarea{margin-top:8px;font-family:ui-monospace,Consolas,monospace;font-size:14px}

/* ---------- guided / explore toolbar with the chapter selector ---------- */
.learning-toolbar{position:fixed;bottom:0;left:0;right:0;z-index:50;display:flex;justify-content:center;align-items:center;gap:14px;
  padding:10px 20px calc(10px + env(safe-area-inset-bottom));color:var(--ink);
  background:color-mix(in srgb,var(--paper) 94%,transparent);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-top:var(--line) solid var(--ink)}
.learning-toolbar label{display:flex;flex-direction:column;gap:4px;font-family:var(--font-body);font-weight:700;font-size:11.5px;letter-spacing:.09em;text-transform:uppercase;color:var(--text-3)}
.learning-toolbar select{width:100%;max-width:320px;min-width:200px;height:44px;padding:0 38px 0 12px;appearance:none;-webkit-appearance:none;cursor:pointer;
  font:600 15px/1.2 var(--font-body);letter-spacing:0;text-transform:none;color:var(--ink);text-overflow:ellipsis;
  background:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='14' height='9' viewBox='0 0 14 9'%3E%3Cpath d='M1.5 1.5 7 7l5.5-5.5' fill='none' stroke='%230A0B0D' stroke-width='2.4' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") right 13px center/14px 9px no-repeat,var(--sheet);
  border:var(--line) solid var(--ink);border-radius:12px;box-shadow:2px 2px 0 var(--ink)}
.learning-toolbar select:focus-visible{outline:3px solid var(--focus);outline-offset:3px}
.learning-toolbar .nav{position:static;transform:none;border:0;box-shadow:none;background:none;padding:0;gap:10px}
.learning-toolbar .nav__btn{width:46px;height:46px;min-height:44px;padding:0;font-size:21px}
.learning-toolbar .nav__count{min-width:58px}
.learning-toolbar .mode-toggle{min-width:124px;align-self:flex-end}
.nav__hint{display:none!important}
.skip-to-lesson{position:fixed;top:-100px;left:12px;z-index:200;background:var(--ink);color:var(--sheet);padding:10px 16px;border-radius:var(--r-sm);font-weight:700;text-decoration:none;transition:top var(--t) var(--ease)}
.skip-to-lesson:focus{top:12px}
:is(button,a,input,textarea,select,summary):focus-visible{outline:3px solid var(--focus);outline-offset:3px}
.slide:focus-visible{outline:none}

/* floating feedback: icon-only, above the toolbar */
body[data-deck] .lh-fab{position:fixed;right:16px;bottom:calc(var(--deck-bottom) - 26px);z-index:48;min-width:46px;min-height:46px;padding:10px 12px;justify-content:center}
body[data-deck] .lh-fab span{display:none}

/* ---------- predict, after answering ---------- */
.quiz-result{margin-top:18px;padding:16px 18px;border:var(--line) solid var(--ink);border-radius:14px;background:var(--pale-2);color:var(--text);box-shadow:var(--sh-sm);font-size:16px;line-height:1.55}
.quiz-result.is-right{background:var(--ok-pale)}
.quiz-result h3{margin:0 0 6px;font-family:var(--font-display);font-weight:700;font-size:18px;line-height:1.25;color:var(--ink)}
.quiz-result p{margin:8px 0 0;color:var(--text-2)}
.slide--predict.revealed .opt__fb{display:none;animation:none}
.slide--predict.revealed .opts>.opt:not(.chosen){display:none}
.slide--predict.revealed .opts>.opt.chosen{cursor:default}
.slide--predict .opts>.opt{display:grid;grid-template-columns:30px minmax(0,1fr);gap:10px 14px}
.slide--predict .opts>.opt .opt__k{grid-column:1;grid-row:1}
.slide--predict .opts>.opt .opt__t{grid-column:2;grid-row:1}
.slide--predict .opt__tag{white-space:normal;max-width:100%;grid-column:2;justify-self:start;margin:0}
.other-answers .opt{display:block;margin:0;padding:12px 0;border-top:1.5px dashed rgba(10,11,13,.2);cursor:default}
.other-answers .opt:first-of-type{border-top:0}
.other-answers .opt__fb{display:block!important;padding:6px 0 0;font-size:15px;line-height:1.55;color:var(--text-2)}
.other-answers .opt__t{display:block;font-family:var(--font-display);font-weight:700;font-size:16px;color:var(--ink)}
.other-answers .opt__k,.other-answers .opt__tag{display:none}

/* ---------- the illustration slot: a die-cut sticker (white border is baked into the art) ---------- */
.lesson-art{margin:0 auto;width:100%;max-width:440px}
.lesson-art:empty{display:none}
.lesson-art img{display:block;width:100%;height:auto;object-fit:contain;border-radius:0;transform:rotate(-2.5deg);
  filter:drop-shadow(0 1px 0 rgba(10,11,13,.12)) drop-shadow(2px 10px 12px rgba(10,11,13,.18));user-select:none;-webkit-user-drag:none}

[hidden]{display:none!important}
@media (min-width:1100px){.model--leverage .model-cells{grid-template-columns:repeat(4,minmax(0,1fr))}}
@media (max-width:700px){
  body[data-deck]{--deck-bottom:158px}
  .slide .scene{gap:22px}
  .model-cells,.model--path .model-cells:has(li:nth-child(4)){grid-template-columns:1fr}
  .model--path .model-cell:not(:last-child)::after,.model--product .model-cell:not(:last-child)::after{right:auto;left:50%;top:auto;bottom:-22px;margin:0 0 0 -14px}
  .model--path .model-cell:not(:last-child)::after{content:"\2193"}
  .model-cells{gap:18px}
  .model--checklist .model-cell{grid-template-columns:36px 1fr;gap:10px}
  .model--checklist .model-cell p{grid-column:2}
  .model-cell h3{font-size:19px}
  .model-cell{padding:16px}
  .model--leverage .model-cells{grid-template-columns:1fr 1fr;gap:12px}
  .model--leverage .model-cell{padding:14px 12px}
  .model--compare .model-cells{grid-template-columns:1fr}
  .model--matrix .model-cell{padding:14px 12px 14px 20px}
  .model--matrix h3{font-size:17px}
  .model,.formula-card{padding:16px 14px}
  .formula{flex-direction:column;align-items:stretch;gap:8px}
  .formula-result{font-size:28px}
  .formula-term{font-size:18px}
  .formula-pair{grid-template-columns:1fr 16px 1fr;gap:6px}
  .formula-term small{font-size:11px;padding:2px 6px}
  .lab-controls{grid-template-columns:1fr}
  .veq-lab,.delta-lab{padding:18px 16px}
  .fanout>div{gap:6px}
  .fanout>div span{font-size:13.5px;padding:6px 10px}
  .learning-toolbar{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:8px 10px;padding:10px 12px calc(10px + env(safe-area-inset-bottom))}
  .learning-toolbar label{grid-column:1/-1;flex-direction:row;align-items:center;gap:10px}
  .learning-toolbar select{flex:1;width:auto;max-width:none;min-width:0;height:44px}
  .learning-toolbar .nav{justify-content:flex-start}
  .learning-toolbar .mode-toggle{align-self:center;min-width:0;font-size:14px;padding:8px 12px}
  .comparison{grid-template-columns:1fr;gap:14px}
  .comparison article{padding:16px 14px}
  .comparison h3{font-size:20px}
  .comparison dd{font-size:15px}
  .learn-detail__body{margin-left:6px;padding-left:16px}
  .worksheet{transform:none}
  .worksheet__actions>button{flex:1 1 auto}
}
@media (max-width:420px){
  .model--leverage .model-cells{grid-template-columns:1fr}
  .learning-toolbar .nav{gap:6px}
  .learning-toolbar .nav__count{min-width:50px;font-size:14px}
}
/* short landscape phones: slimmer chrome, one toolbar row */
@media (max-height:500px) and (min-width:701px){
  body[data-deck]{--deck-top:70px;--deck-bottom:84px}
  .learning-toolbar{padding:6px 16px calc(6px + env(safe-area-inset-bottom));gap:10px}
  .learning-toolbar label{font-size:0;gap:0}
  .learning-toolbar select{font-size:14px;height:44px;min-width:180px;max-width:260px}
  .learning-toolbar .mode-toggle{align-self:center}
  .crest,.crumb{top:10px}
}
/* below 1180px (where it would sit on the sheet) and on short screens the floating button moves to the free space between the top chips */
@media (max-width:1180px),(max-height:500px){
  body[data-deck] .lh-fab{top:14px;bottom:auto;right:auto;left:50%;transform:translateX(-50%);min-width:44px;min-height:44px;padding:9px 11px}
  body[data-deck] .lh-fab:hover{transform:translate(calc(-50% - 1px),-2px)}
  body[data-deck] .lh-fab:active{transform:translate(calc(-50% + 2px),2px)}
}
@media (max-width:640px){body[data-deck] .lh-fab{top:12px}}
@media (prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;animation:none!important;transition:none!important}}
@media print{
  body[data-deck],html{height:auto;overflow:visible;background:white}
  body.paper::before{display:none}
  .deck{height:auto;overflow:visible}
  .slide{display:block;position:static;overflow:visible;padding:24px;break-after:page;background:white;color:#111}
  .inner{box-shadow:none;animation:none}
  .learning-toolbar,.lh-fab,.crest,.crumb,.lesson-skip,.progress{display:none}
  .learn-detail::details-content{block-size:auto}
}