/* PaperWize learn pages. Cut-paper look: warm paper, stacked sheets, tape, torn edges. */
:root,html[data-theme="light"]{
  --bg:#fdf3e1; --bg2:#f7e8cc; --sheet:#fffaf1; --ink:#2a2f3b; --muted:#6a665d;
  --blue:#2f5d78; --blue2:#7fa6c0; --blue3:#dbe8f0; --mustard:#e9a93a; --terra:#c8643a; --kraft:#d2b48c;
  --line:#e8d9ba; --good:#2e7d4f; --goodbg:#e2f1e5; --bad:#b3402f; --badbg:#f9e3dd;
  --btn:#2f5d78; --btn-edge:#1d3d51; --btn-ink:#fff; --hero:#2f5d78; --hero-ink:#fffaf1; --grain:.5;
  --shadow:0 1px 1px rgba(70,45,10,.08),0 10px 22px -10px rgba(70,45,10,.34);
  color-scheme:light;
}
html[data-theme="dark"]{
  --bg:#1b2024; --bg2:#242a2f; --sheet:#272e34; --ink:#f1e9d8; --muted:#b5b9b8;
  --blue:#7fb3cf; --blue2:#4d7b94; --blue3:#2b4351; --mustard:#e9b45a; --terra:#e28a60; --kraft:#6f5f48;
  --line:#3a444b; --good:#7ddc96; --goodbg:#1f3a28; --bad:#ff9d8c; --badbg:#432622;
  --btn:#7fb3cf; --btn-edge:#4d7b94; --btn-ink:#10212b; --hero:#27485b; --hero-ink:#fffaf1; --grain:0;
  --shadow:0 1px 1px rgba(0,0,0,.3),0 10px 22px -10px rgba(0,0,0,.6);
  color-scheme:dark;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:76px}
body{margin:0;background:var(--bg);color:var(--ink);font:18px/1.6 "Atkinson Hyperlegible",system-ui,sans-serif;position:relative}
body:before{content:"";position:fixed;inset:0;pointer-events:none;z-index:0;opacity:var(--grain);mix-blend-mode:multiply;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='220' height='220'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 .55 0 0 0 0 .42 0 0 0 0 .25 0 0 0 .09 0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E")}
body>*{position:relative;z-index:1}
h1,h2,h3,.logo{font-family:"Bricolage Grotesque","Atkinson Hyperlegible",system-ui,sans-serif;line-height:1.12;margin:0}
h1{font-size:clamp(2.3rem,6vw,3.8rem);font-weight:800;letter-spacing:-.025em}
h2{font-size:clamp(1.6rem,3.6vw,2.2rem);font-weight:800;letter-spacing:-.01em}
h3{font-size:1.1rem;font-weight:700;margin:.2rem 0 .3rem}
p{margin:.5rem 0}
a{color:var(--blue)}
.wrap{max-width:1320px;margin:0 auto;padding:0 18px}
.skip{position:absolute;left:-999px;top:0;background:var(--blue);color:#fff;padding:8px 12px;z-index:90}
.skip:focus{left:8px;top:8px}
:focus-visible{outline:3px solid var(--mustard);outline-offset:2px;border-radius:4px}
em{font-style:normal}
.small{font-size:.88rem;color:var(--muted)}

/* header */
.top{position:sticky;top:0;z-index:30;background:color-mix(in srgb,var(--bg) 90%,transparent);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.top .wrap{display:flex;align-items:center;justify-content:space-between;height:58px}
.logo{font-size:1.5rem;text-decoration:none;color:var(--ink);font-weight:700}
.logo b{color:var(--terra);font-weight:800}
.top nav{display:flex;align-items:center;gap:6px}
.top nav a{padding:6px 12px;text-decoration:none;color:var(--ink);font-weight:700;font-size:.95rem;border-radius:8px}
.top nav a:hover{background:var(--bg2)}
.theme{width:38px;height:38px;border-radius:10px;border:2px solid var(--line);background:var(--sheet);color:var(--ink);display:grid;place-items:center;cursor:pointer;margin-left:6px}
.theme svg{width:20px;height:20px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
html[data-theme=light] .i-sun{display:none}
html[data-theme=dark] .i-moon{display:none}

/* buttons: little cut-paper blocks */
.btn{font:700 1rem "Atkinson Hyperlegible",system-ui,sans-serif;background:var(--btn);color:var(--btn-ink);border:0;border-radius:10px;
  padding:10px 18px;cursor:pointer;box-shadow:0 3px 0 var(--btn-edge);transition:transform .08s,box-shadow .08s}
.btn:hover{filter:brightness(1.06)}
.btn:active{transform:translateY(2px);box-shadow:0 1px 0 var(--btn-edge)}
.btn.light{background:#fffaf1;color:#1d3d51;box-shadow:0 3px 0 rgba(0,0,0,.25)}
.btn.line{background:transparent;color:var(--hero-ink);box-shadow:inset 0 0 0 2px rgba(255,250,241,.7)}
.btn[aria-pressed=true]{background:var(--mustard);color:#2a1d06}
.btn.sm{padding:6px 12px;font-size:.92rem}

/* hero: blue paper with torn edges */
.hero{background:var(--hero);color:var(--hero-ink);padding:34px 0 96px;position:relative;isolation:isolate}
.hero:before,.hero:after{content:"";position:absolute;left:0;right:0;bottom:-1px;z-index:-1}
.hero:before{height:48px;background:var(--kraft);bottom:-9px}
.hero:after{height:44px;background:var(--bg)}
.hero-in{display:grid;grid-template-columns:1.3fr 1fr;gap:34px;align-items:center}
.hero-text{padding-bottom:10px}
.crumbs{font-size:.9rem;margin:0 0 10px;opacity:.85}
.crumbs a{color:inherit}
.hero h1{color:var(--hero-ink)}
.sub{font-size:1.25rem;max-width:30em;opacity:.95}
.meta{display:flex;flex-wrap:wrap;gap:8px;margin:14px 0;padding:0}
.meta span{background:rgba(255,250,241,.16);border-radius:6px;padding:2px 12px;font-size:.9rem;font-weight:700}
.hero-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:14px}
.kas-stage{width:100%;aspect-ratio:1/1;position:relative;background:#f7efe0;padding:0;border:8px solid #fffaf1;border-radius:3px;box-shadow:0 14px 26px -10px rgba(0,0,0,.5);transform:rotate(1.6deg)}
.kas-stage canvas{width:100%;height:100%;display:none}
.kas-stage img{position:absolute;inset:0;height:100%;width:100%;display:block;object-fit:contain}
.hear{margin-top:-6px;z-index:2}
.play{font-size:.8em;margin-right:4px}
.bubble{position:absolute;bottom:calc(100% - 40px);right:55%;width:min(300px,90vw);background:var(--sheet);color:var(--ink);border-radius:16px;padding:10px 16px;
  box-shadow:var(--shadow);font-size:1rem;z-index:5;pointer-events:none}
.bubble:after{content:"";position:absolute;bottom:-9px;right:30px;width:18px;height:18px;background:var(--sheet);transform:rotate(45deg)}
.bubble[hidden]{display:none}
.bubble .who{display:inline-block;background:#c8382d;color:#fff;border-radius:6px;font-size:.75rem;font-weight:700;padding:0 10px}
.bubble p{margin:2px 0 0}

/* layout */
.layout{display:grid;grid-template-columns:170px minmax(0,1fr) 210px;gap:28px;align-items:start;margin-top:8px;max-width:1320px}
.toc{position:sticky;top:78px;font-size:.95rem}
.toc-h,.label{font:700 .78rem "Atkinson Hyperlegible",sans-serif;text-transform:uppercase;letter-spacing:.12em;color:var(--blue);margin:0 0 6px}
.toc ol{list-style:none;margin:0;padding:0;border-left:3px solid var(--line)}
.toc li a{display:block;padding:5px 12px;text-decoration:none;color:var(--muted);margin-left:-3px;border-left:3px solid transparent}
.toc li a:hover{color:var(--ink)}
.toc li a.on{border-left-color:var(--terra);font-weight:700;color:var(--ink)}
.body{min-width:0}

/* in one minute */
.inone{background:var(--sheet);color:var(--ink);border-radius:4px;padding:16px 22px 14px;box-shadow:0 14px 26px -10px rgba(0,0,0,.45);transform:rotate(1.2deg)}
.inone ul{margin:0;padding-left:1.1rem}
.inone li{margin:.15rem 0;break-inside:avoid}

/* sheets: stacked paper */
.sheet{background:var(--sheet);border-radius:4px;padding:28px 30px 30px;margin:0 0 40px;box-shadow:7px 8px 0 var(--stack,var(--blue3)),var(--shadow);position:relative}
.sheet.s0{--stack:var(--blue3)}.sheet.s1{--stack:color-mix(in srgb,var(--mustard) 38%,var(--sheet))}.sheet.s2{--stack:color-mix(in srgb,var(--terra) 30%,var(--sheet))}
.m-head{display:flex;align-items:center;gap:16px;margin-bottom:18px}
.m-head.plain{margin-bottom:10px}
.m-head>div{flex:1;min-width:0}
.num{flex:none;width:54px;height:54px;border-radius:50%;background:var(--mustard);color:#2a1d06;display:grid;place-items:center;font:800 1.7rem "Bricolage Grotesque",sans-serif;
  box-shadow:3px 3px 0 var(--btn-edge);transform:rotate(-5deg)}
.tagline{margin:.2rem 0 0;color:var(--muted);font-size:1.05rem}
.big{font-size:1.38rem;line-height:1.5;margin:.2rem 0 .6rem;color:var(--ink)}
.bang{flex:none;width:38px;height:38px;border-radius:50%;border:0;background:var(--terra);color:#fff;font:800 1.25rem "Bricolage Grotesque",sans-serif;cursor:pointer;box-shadow:0 3px 0 rgba(0,0,0,.25)}
.bang:hover{filter:brightness(1.1)}
.tag{display:inline-block;background:var(--blue3);color:var(--ink);font-size:.74rem;font-weight:700;border-radius:4px;padding:1px 9px;letter-spacing:.04em;text-transform:uppercase}

/* method: the explanation leads */
.m-main{display:grid;gap:26px;align-items:center}
.m-main.with-fig{grid-template-columns:1fr 1.15fr}
.m-text .label{color:var(--terra)}
.m-main.no-fig .big{max-width:34em}
.steps{list-style:none;padding:0;margin:20px 0 0;display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:10px}
.steps li{display:flex;gap:10px;align-items:flex-start;background:var(--bg2);border-radius:6px;padding:10px 12px;font-size:.97rem}
.steps li span{flex:none;width:1.6em;height:1.6em;border-radius:50%;background:var(--blue);color:var(--btn-ink);display:grid;place-items:center;font-weight:700;font-size:.85rem}
.steps li p{margin:0;line-height:1.35}
.m-row{display:flex;flex-wrap:wrap;gap:14px;align-items:center;justify-content:space-between;margin-top:18px}
.usewhen{margin:0;color:var(--muted);font-size:1rem;flex:1 1 220px}
.usewhen b{color:var(--ink)}
.case-btn{text-align:left;display:flex;flex-direction:column;align-items:flex-start;line-height:1.25;background:var(--terra);color:#fff;box-shadow:0 3px 0 rgba(0,0,0,.28);padding:9px 16px}
html[data-theme=dark] .case-btn{color:#2a1208}
.case-btn small{font-weight:400;opacity:.92;font-size:.85rem}
.slip{background:var(--bg2);border-radius:4px;padding:8px 16px;margin:18px 0 0;position:relative;box-shadow:var(--shadow);transform:rotate(-.25deg);font-size:.98rem}
.slip.safe{background:var(--badbg)}
.slip b{font-size:.78rem;text-transform:uppercase;letter-spacing:.1em}
.slip p{margin:.1rem 0}
.slip.stretch{display:none}
body.show-stretch .slip.stretch{display:block}

/* pictures: prints with tape */
.fig{margin:0;position:relative}
.hs-img{position:relative;background:#fffaf1;padding:8px;border-radius:3px;box-shadow:var(--shadow);transform:rotate(.6deg)}
.hs-img img{width:100%;height:auto;display:block}
.hs-arrow{position:absolute;inset:8px;width:calc(100% - 16px);height:calc(100% - 16px);pointer-events:none;overflow:visible}
.hs-arrow marker path{fill:#2a2f3b}
.hs-path{fill:none;stroke:#2a2f3b;stroke-width:3.5;stroke-linecap:round;display:none}
.hs-path.show{display:block}
.hs-label{position:absolute;background:#fffaf1;color:#2a2f3b;border-radius:4px;padding:2px 10px;font:700 .86rem/1.3 "Bricolage Grotesque",sans-serif;box-shadow:0 2px 6px rgba(0,0,0,.28);z-index:2;white-space:nowrap;pointer-events:none}
.hs-label[hidden]{display:none}
.dot{position:absolute;width:26px;height:26px;margin:-13px 0 0 -13px;border-radius:50%;border:3px solid #fffaf1;background:var(--blue);cursor:pointer;z-index:4;padding:0;
  box-shadow:0 1px 4px rgba(0,0,0,.4)}
.dot:hover{background:var(--terra)}
.dot.on{background:var(--mustard);transform:scale(1.15)}
.dot.pulse{animation:pulse 2.6s ease-out infinite}
@keyframes pulse{0%{box-shadow:0 0 0 0 color-mix(in srgb,var(--blue) 75%,transparent),0 1px 4px rgba(0,0,0,.4)}
  60%,100%{box-shadow:0 0 0 16px transparent,0 1px 4px rgba(0,0,0,.4)}}
.hs-cap[hidden]{display:none}
.hs-cap{margin-top:14px;background:var(--bg2);border-radius:6px;padding:8px 14px;display:flex;gap:12px;align-items:center;justify-content:space-between;min-height:62px}
.hs-text{margin:0;font-size:1rem;line-height:1.4}
.hs-nav{display:none;align-items:center;gap:8px;flex:none;font-size:.9rem;color:var(--muted)}
.hs-nav.on{display:flex}
.hs-nav button{width:34px;height:34px;border-radius:8px;border:0;background:var(--btn);color:var(--btn-ink);font-size:1.3rem;line-height:1;cursor:pointer;box-shadow:0 2px 0 var(--btn-edge)}

/* words and popovers */
.term{font:inherit;color:inherit;background:linear-gradient(transparent 62%,color-mix(in srgb,var(--mustard) 42%,transparent) 62%);border:0;border-bottom:2px dotted var(--blue);padding:0 1px;cursor:help;text-align:inherit}
.term:hover{background:color-mix(in srgb,var(--mustard) 40%,transparent)}
.chips{display:flex;flex-wrap:wrap;gap:8px;margin:2px 0 10px}
.term.chip{background:var(--bg2);border:0;border-radius:6px;padding:3px 12px;box-shadow:0 2px 0 var(--line);cursor:help}
.pop{position:absolute;z-index:60;width:min(320px,calc(100vw - 24px));background:var(--sheet);color:var(--ink);border-radius:6px;padding:12px 30px 14px 16px;box-shadow:0 14px 30px -8px rgba(0,0,0,.45),0 0 0 1px var(--line);font-size:1rem;line-height:1.45}
.pop[hidden]{display:none}
.pop:before{content:"";position:absolute;top:-8px;left:var(--ax,24px);width:16px;height:16px;background:var(--sheet);transform:rotate(45deg);box-shadow:-1px -1px 0 var(--line)}
.pop.up:before{top:auto;bottom:-8px;transform:rotate(225deg)}
.pop h4{margin:0 0 2px;font:800 1.05rem "Bricolage Grotesque",sans-serif}
.pop.mistake h4{color:var(--terra)}
.pop p{margin:.2rem 0 0}
.pop .close{position:absolute;top:4px;right:6px;border:0;background:none;font-size:1.3rem;color:var(--muted);cursor:pointer}
.case{border:0;border-radius:6px;padding:28px 30px 26px;max-width:min(620px,calc(100vw - 24px));background:var(--sheet);color:var(--ink);box-shadow:0 30px 60px -12px rgba(0,0,0,.55)}
.case::backdrop{background:rgba(25,20,10,.55);backdrop-filter:blur(2px)}
.case h2{font-size:1.7rem;margin-bottom:8px}
.case p{font-size:1.1rem}
.case .science{background:var(--blue3);border-radius:6px;padding:10px 16px;margin-top:14px;font-size:1rem}
.case .science b{display:block;font-size:.78rem;text-transform:uppercase;letter-spacing:.1em;color:var(--blue)}
.case .x{position:absolute;top:8px;right:12px;border:0;background:none;font-size:1.8rem;color:var(--muted);cursor:pointer;line-height:1}

/* checks and quiz */
.check,.qbox,.choose-row{border-top:2px dashed var(--line);margin-top:20px;padding-top:14px}
.choose-row{margin-top:12px}
.q{font-weight:700;margin:0 0 8px;font-size:1.05rem}
.q .n{display:inline-grid;place-items:center;width:1.7em;height:1.7em;background:var(--blue);color:var(--btn-ink);border-radius:50%;margin-right:6px;font-size:.9rem}
.opts{display:flex;flex-wrap:wrap;gap:8px}
.opts.stack{flex-direction:column;align-items:stretch}
.opts button{font:inherit;background:var(--bg2);color:var(--ink);border:2px solid transparent;border-radius:8px;padding:8px 14px;cursor:pointer;text-align:left}
.opts button:hover:not(:disabled){border-color:var(--blue)}
.opts button.on{border-color:var(--blue);background:var(--blue3)}
.opts button.right{background:var(--goodbg);border-color:var(--good)}
.opts button.wrong{background:var(--badbg);border-color:var(--bad)}
.opts button:disabled{cursor:default;opacity:1}
.opts .ltr{display:inline-grid;place-items:center;width:1.5em;height:1.5em;border-radius:50%;background:var(--sheet);margin-right:8px;font-weight:700;font-size:.85rem}
.fb{margin:8px 0 0;font-size:.98rem}
.fb.ok{color:var(--good)}.fb.no{color:var(--bad)}.fb:empty{display:none}
.score{font-weight:700;color:var(--blue);margin-top:12px}
.result{margin-top:16px;text-align:center;background:var(--bg2);border-radius:8px;padding:14px}
.result:empty{display:none}
.result .big2{font:800 2.6rem "Bricolage Grotesque",sans-serif;margin:0;color:var(--blue)}
.explain-h{margin-top:30px}
textarea{width:100%;font:inherit;padding:10px;border:2px solid var(--line);border-radius:8px;background:var(--sheet);color:var(--ink);margin-bottom:8px;resize:vertical}
.mark{background:var(--bg2);border-radius:8px;padding:6px 16px;margin-top:10px}
.keys{list-style:none;padding:0}.keys li{margin:.3rem 0}
.keys input{width:1.1rem;height:1.1rem;margin-right:6px;accent-color:var(--blue)}
.tally{font-weight:700;color:var(--blue)}
.flow{margin-top:14px;background:var(--bg2);border-radius:8px;padding:8px 14px}
.flow summary{cursor:pointer;font-weight:700}

/* mixture / why / parents */
.why-grid,.p-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:10px}
.why-card,.p-item{background:var(--bg2);border-radius:6px;padding:14px 16px}
.why-card h3{margin-top:8px;font-size:1.25rem}
.why-card p,.p-item p{font-size:.98rem;margin:.3rem 0 0}
.pts{padding-left:1.2rem;color:var(--muted)}
.earlier{background:var(--bg2);border-radius:6px;padding:10px 14px;font-size:.97rem;color:var(--muted)}
.soonlink{display:inline-block;border:1px dashed var(--muted);border-radius:6px;padding:0 10px;margin:4px 6px 0 0;font-size:.85rem}
.soonlink em,.further em{font-size:.72rem;font-weight:700;color:var(--terra);margin-left:4px;text-transform:uppercase;letter-spacing:.06em}
.parents{--stack:color-mix(in srgb,var(--mustard) 38%,var(--sheet))}
.further{list-style:none;padding:0}
.further li{padding:6px 0;border-bottom:1px solid var(--line)}
.lvl{display:inline-block;background:var(--bg2);border-radius:4px;padding:0 8px;font-size:.78rem;font-weight:700;margin-right:6px}
.enrich{background:var(--bg2);border-radius:6px;padding:8px 18px 12px;margin-top:16px}
.eq{font:700 1.25rem "Bricolage Grotesque",sans-serif}

.chk{display:block;margin:8px 0;font-size:.95rem}
.chk input{accent-color:var(--terra);margin-right:6px}
.row{display:flex;gap:8px;margin:10px 0}
.warnp{color:var(--bad)}
.rf{border-collapse:collapse;width:100%;font-size:.95rem}
.rf th,.rf td{border-bottom:1px solid var(--line);padding:4px 8px;text-align:left}
.dotc{display:inline-block;width:.8em;height:.8em;border-radius:50%;margin-right:6px}

/* home */
.home-hero{padding:56px 0 100px}
.home-h{margin:26px 0 16px}
.lesson-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:22px}
.lesson-card{display:block;background:var(--sheet);border-radius:4px;text-decoration:none;color:var(--ink);box-shadow:var(--shadow);overflow:hidden;transition:transform .12s}
a.lesson-card:hover{transform:translateY(-4px) rotate(-.4deg)}
.lesson-card img{display:block;width:100%;aspect-ratio:3/2;object-fit:cover}
.lc-body{padding:12px 16px 16px}
.lc-tag{margin:0;font:700 .74rem "Atkinson Hyperlegible",sans-serif;letter-spacing:.1em;text-transform:uppercase;color:var(--terra)}
.lesson-card h3{font-size:1.35rem;margin:.1rem 0 .2rem}
.lesson-card p{color:var(--muted);font-size:.98rem;margin:0}
.lesson-card.ghost{background:transparent;box-shadow:none;border:2px dashed var(--line);display:grid;align-items:center;min-height:120px}
.lesson-card.ghost h3{color:var(--muted)}
.about{margin-bottom:30px}
.foot{border-top:1px solid var(--line);padding:24px 0 40px;margin-top:30px;color:var(--muted)}

@media (max-width:900px){
  .hero-in{grid-template-columns:1fr}
  .hero{padding-bottom:70px}
  .layout{grid-template-columns:1fr}
  .toc{position:static;overflow-x:auto}
  .toc ol{display:flex;gap:6px;border:0}
  .toc li a{border:0;border-radius:6px;white-space:nowrap;margin:0;padding:4px 12px;background:var(--bg2)}
  .toc li a.on{background:var(--mustard);color:#2a1d06}
  .m-main.with-fig,.why-grid,.p-grid{grid-template-columns:1fr}
  .inone ul{columns:1}
  .sheet{padding:22px 18px 24px}
  .big{font-size:1.2rem}
  .hs-label{font-size:.72rem;padding:1px 7px}
}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}.dot.pulse{animation:none}}

@media print{
  @page{size:A4;margin:14mm}
  html,body{background:#fff!important;color:#000}
  body{font-size:11pt}
  body:before,.top,.toc,.hero-kas,.hero-actions,.foot .small,[data-widget=choose],[data-widget=chromatography],.flow,#stretchToggle,.skip,.bang,.case-btn,.hs-nav,.dot,.hs-arrow,.hs-label,.inone,.hs-cap{display:none!important}
  .hero{background:#fff!important;color:#000;padding:0}.hero:before,.hero:after{display:none}.hero h1{color:#000}
  .hero-in{grid-template-columns:1fr}
  .sheet{box-shadow:none;border:1px solid #999;break-inside:avoid;margin-bottom:8mm;background:#fff}
  .layout{display:block}
  .slip.stretch{display:block}.slip{box-shadow:none;border:1px solid #999;transform:none}  .hs-img{box-shadow:none;transform:none;padding:0}  .m-main.with-fig{grid-template-columns:1fr 1fr}
  .opts button{border:1px solid #999;background:#fff;color:#000}
  textarea{border:1px solid #999;min-height:30mm}
  .check:after{content:"Write your answer: ______________________________________";display:block;margin-top:8px}
  a{color:#000;text-decoration:none}
}

/* one-at-a-time games */
.prog{display:flex;align-items:center;gap:12px;font-weight:700;color:var(--muted);font-size:.95rem;margin:6px 0 10px}
.bar{flex:1;height:8px;background:var(--bg2);border-radius:99px;overflow:hidden}
.bar i{display:block;height:100%;background:var(--mustard);border-radius:99px;transition:width .3s}
.prompt{font:800 clamp(1.3rem,3vw,1.7rem)/1.2 "Bricolage Grotesque",sans-serif;margin:4px 0 16px}
.prompt.sm{font-size:1.3rem;margin-bottom:12px}
.pics{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}
.pic{background:#fffaf1;border:0;border-radius:4px;padding:8px 8px 10px;cursor:pointer;box-shadow:var(--shadow);font:700 1.05rem "Bricolage Grotesque",sans-serif;color:#2a2f3b;
  display:flex;flex-direction:column;gap:8px;text-align:center;transition:transform .1s;outline-offset:3px}
.pic img{width:100%;aspect-ratio:16/9;object-fit:cover;border-radius:2px;display:block}
.pic:hover:not(:disabled){transform:translateY(-3px) rotate(-.5deg)}
.pic.right{box-shadow:0 0 0 4px var(--good),var(--shadow)}
.pic.wrong{opacity:.45;filter:grayscale(.6)}
.pic:disabled{cursor:default}
.qlayout{display:grid;grid-template-columns:1fr 1.2fr;gap:22px;align-items:start}
.qimg{margin:0;background:#fffaf1;padding:8px;border-radius:3px;box-shadow:var(--shadow);transform:rotate(-.6deg)}
.qimg img{width:100%;aspect-ratio:3/2;object-fit:cover;display:block}
#choose .btn,#quiz .btn{margin-top:14px}

/* parents: progressive disclosure */
.p-list{display:grid;gap:10px;margin-top:6px}
.p-item{background:var(--bg2);border-radius:6px;padding:0}
.p-item summary{list-style:none;cursor:pointer;padding:12px 18px;display:flex;flex-wrap:wrap;align-items:baseline;gap:4px 14px;position:relative;padding-right:44px}
.p-item summary::-webkit-details-marker{display:none}
.p-item summary:after{content:"+";position:absolute;right:16px;top:8px;font:700 1.6rem "Bricolage Grotesque",sans-serif;color:var(--terra)}
.p-item[open] summary:after{content:"–"}
.p-item summary b{font:700 1.15rem "Bricolage Grotesque",sans-serif}
.p-item summary span{color:var(--muted);font-size:.95rem}
.p-item p{margin:0;padding:0 18px 14px;font-size:1rem}

/* go further: a mission with video */
.mission{display:grid;grid-template-columns:1.1fr 1fr;gap:26px;align-items:center;margin-top:8px}
.vid-poster{position:relative;display:block;width:100%;padding:8px;background:#fffaf1;border:0;border-radius:3px;box-shadow:var(--shadow);cursor:pointer;transform:rotate(-.6deg)}
.vid-poster img{width:100%;aspect-ratio:16/9;object-fit:cover;display:block;filter:brightness(.78)}
.vid-play{position:absolute;left:50%;top:44%;transform:translate(-50%,-50%);width:76px;height:76px;border-radius:50%;background:var(--terra);color:#fff;display:grid;place-items:center;font-size:2rem;padding-left:6px;box-shadow:0 4px 0 rgba(0,0,0,.3)}
.vid-poster:hover .vid-play{filter:brightness(1.1)}
.vid-cap{position:absolute;left:8px;right:8px;bottom:8px;padding:8px 14px;background:rgba(25,25,30,.72);color:#fff;font:700 1rem "Bricolage Grotesque",sans-serif;text-align:left}
.vid-frame{width:100%;aspect-ratio:16/9;border:0;border-radius:3px;display:block;background:#000}
.mtitle{font-size:1.7rem;margin:.1rem 0}
.tasks{padding-left:1.2rem;margin:8px 0}.tasks li{margin:.25rem 0}
.outcome{background:var(--bg2);border-radius:6px;padding:8px 14px}
.next-h{margin:30px 0 6px;font-size:1.05rem;font-weight:700;color:var(--muted)}
@media (max-width:900px){.qlayout,.mission{grid-template-columns:1fr}.pics{gap:10px}}

/* Kas dock: stays beside the lesson as you scroll */
.rail{position:sticky;top:76px;align-self:start}
.kas-dock{position:relative;display:flex;flex-direction:column;align-items:center;gap:8px}
.rail-hint{font-size:.85rem;color:var(--muted);text-align:center;margin:0}
.bubble{bottom:auto;top:100%;margin-top:8px;right:auto;left:-10px;width:230px;transform:none}
.bubble:after{right:auto;left:60px;bottom:auto;top:-9px}
.hear{width:100%}
.speak{display:inline-flex;align-items:center;gap:6px;margin:0 0 8px;padding:5px 12px;border-radius:99px;border:2px solid var(--line);background:var(--bg2);color:var(--ink);font:700 .88rem "Atkinson Hyperlegible",sans-serif;cursor:pointer}
.speak:hover,.speak.on{border-color:var(--terra)}
.speak.on{background:color-mix(in srgb,var(--terra) 18%,var(--sheet))}
.reading{background:color-mix(in srgb,var(--mustard) 30%,transparent);border-radius:4px;box-shadow:0 0 0 6px color-mix(in srgb,var(--mustard) 30%,transparent)}

/* why-it-matters picture cards */
.why-grid{align-items:start}
.why-card{padding:0;background:transparent}
.why-btn{display:block;width:100%;position:relative;background:#fffaf1;border:0;border-radius:4px;padding:8px 8px 12px;text-align:left;cursor:pointer;box-shadow:var(--shadow);color:#2a2f3b;transition:transform .12s}
.why-btn:hover{transform:translateY(-3px) rotate(-.4deg)}
.why-btn img{display:block;width:100%;aspect-ratio:3/2;object-fit:cover;object-position:50% 35%;border-radius:2px;margin-bottom:10px}
.why-title{display:block;font:800 1.2rem/1.2 "Bricolage Grotesque",sans-serif;margin-top:6px;padding-right:40px}
.why-plus{position:absolute;right:14px;bottom:10px;width:28px;height:28px;border-radius:50%;background:var(--terra);color:#fff;display:grid;place-items:center;font:700 1.3rem/1 "Bricolage Grotesque",sans-serif}
.why-text{background:var(--bg2);border-radius:4px;padding:10px 14px;margin:8px 0 0;font-size:1rem}
.why-text[hidden]{display:none}

/* case modal figure */
.case-img{margin:10px 0 14px;background:#fffaf1;padding:6px;border-radius:3px;box-shadow:var(--shadow)}
.case-img img{width:100%;display:block;max-height:280px;object-fit:cover}
.case{overflow:auto;max-height:calc(100vh - 32px)}

/* sieve activity */
.try{display:flex;flex-wrap:wrap;align-items:center;gap:12px;margin-top:18px}
.try[hidden]{display:none}
.pwi{--pwi-ink:var(--ink);--pwi-paper:var(--bg2);--pwi-card:var(--sheet);--pwi-teal:var(--blue);--pwi-line:var(--line);font-family:inherit}
.pwi-stage{border:0;border-radius:4px;box-shadow:var(--shadow)}
.pwi-predict{background:var(--bg2);color:var(--ink)}
.pwi-btn{border:0;box-shadow:0 3px 0 var(--btn-edge);background:var(--btn);color:var(--btn-ink)}

@media (max-width:1100px){
  .layout{grid-template-columns:170px minmax(0,1fr)}
  .rail{position:fixed;right:10px;bottom:10px;top:auto;width:92px;z-index:40}
  .rail .kas-stage{border-width:4px}
  .rail-hint,.rail .hear{display:none}
  .bubble{left:auto;right:0;width:min(240px,70vw);top:auto;bottom:100%;margin:0 0 10px}
  .bubble:after{left:auto;right:28px;top:auto;bottom:-9px}
}
@media (max-width:900px){
  .hero-in{grid-template-columns:1fr}
  .layout{grid-template-columns:1fr}
}

/* mission: video beside its questions */
.mlabel{color:var(--terra);margin-top:4px}
.mission{grid-template-columns:1fr 1fr;align-items:start}
.vid-title{font:700 1.05rem "Bricolage Grotesque",sans-serif;margin:10px 0 2px}
.vq{background:var(--bg2);border-radius:8px;padding:16px 18px}
.vq .prompt.sm{font-size:1.15rem}
.vq textarea{margin-bottom:8px}
@media (max-width:900px){.mission{grid-template-columns:1fr}}

.kas-mouth{position:absolute;inset:0;width:100%;height:100%;pointer-events:none;overflow:visible;z-index:2}
.kas-mouth[hidden]{display:none}

/* modal must stay fixed in the viewport (body>* sets position:relative) */
dialog.case{position:fixed;inset:0;margin:auto;z-index:100}
dialog.case:not([open]){display:none}

/* method label */
.steps-label{margin:20px 0 6px}
.steps-label span{font-weight:400;text-transform:none;letter-spacing:0;color:var(--muted);font-size:.9rem}
.steps-label+.steps{margin-top:0}

/* learning objectives inside the In-one-minute note */
.obj-btn{display:flex;align-items:center;justify-content:space-between;gap:10px;width:100%;margin-top:10px;padding:8px 0 0;border:0;border-top:2px dashed var(--line);background:none;color:var(--ink);font:700 1rem "Atkinson Hyperlegible",sans-serif;cursor:pointer;text-align:left}
.obj-btn .why-plus{position:static;flex:none}
.objectives{padding-top:4px}
.objectives[hidden]{display:none}
.objectives ul{margin:.2rem 0 0;padding-left:1.1rem}

/* settings */
.settings{position:relative}
.gear{width:38px;height:38px;border-radius:10px;border:2px solid var(--line);background:var(--sheet);color:var(--ink);display:grid;place-items:center;cursor:pointer;margin-left:6px}
.gear svg{width:21px;height:21px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linejoin:round}
.settings-panel{position:absolute;right:0;top:46px;width:250px;background:var(--sheet);color:var(--ink);border-radius:6px;padding:12px 16px 10px;box-shadow:0 14px 30px -8px rgba(0,0,0,.45),0 0 0 1px var(--line);z-index:70}
.settings-panel[hidden]{display:none}
.sw{display:flex;align-items:center;gap:12px;padding:8px 0;cursor:pointer;font-size:1rem}
.sw input{appearance:none;width:42px;height:24px;border-radius:99px;background:var(--line);position:relative;flex:none;cursor:pointer;transition:background .15s}
.sw input:after{content:"";position:absolute;left:3px;top:3px;width:18px;height:18px;border-radius:50%;background:#fffaf1;box-shadow:0 1px 2px rgba(0,0,0,.3);transition:left .15s}
.sw input:checked{background:var(--blue)}
.sw input:checked:after{left:21px}
.hide-kas .rail{display:none}
.hide-kas .layout{grid-template-columns:170px minmax(0,1fr)}
.hide-cases .case-btn{display:none}
.hide-checks .check{display:none}
@media (max-width:900px){.hide-kas .layout{grid-template-columns:1fr}}

/* about page */
.about-wrap{max-width:900px}
.maker{display:grid;grid-template-columns:200px 1fr;gap:28px;align-items:center}
.maker-print{background:#fffaf1;padding:8px;border-radius:3px;box-shadow:var(--shadow);transform:rotate(-1.5deg)}
.maker-ph{aspect-ratio:3/4;background:var(--bg2);display:grid;place-items:center;text-align:center;color:var(--muted);font-weight:700}
@media (max-width:700px){.maker{grid-template-columns:1fr}.maker-print{max-width:200px}}

.hide-kas .speak{display:none}

.maker.solo{display:block}
.maker-print img{display:block;width:100%;height:auto}

/* key information stays in the main text, beside the picture and above any demo */
.usewhen{color:var(--ink);font-size:1.05rem;margin:.9rem 0 0;flex:none}
.m-text .steps{grid-template-columns:1fr;margin-top:6px}
.m-main.no-fig .m-text .steps{grid-template-columns:repeat(auto-fit,minmax(200px,1fr))}
.m-row{justify-content:flex-start}

/* full screen: an icon on the thing itself */
.fs-btn{position:absolute;top:10px;right:10px;z-index:7;width:34px;height:34px;display:grid;place-items:center;padding:0;border:0;border-radius:50%;background:rgba(255,250,241,.94);color:#2a2f3b;cursor:pointer;box-shadow:0 2px 6px rgba(0,0,0,.3)}
.fs-btn svg{width:18px;height:18px;fill:none;stroke:currentColor;stroke-width:2.2;stroke-linecap:round;stroke-linejoin:round}
.fs-btn:hover{background:#fff}
.hs-img,.pwi-stage{position:relative}
.fs{position:fixed;inset:0;z-index:90;background:var(--bg);padding:56px 18px 18px;overflow:auto;display:flex;flex-direction:column;align-items:center;justify-content:center}
.fs .fs-btn{position:fixed;top:14px;right:14px}
.hs.fs .hs-img{width:min(100%,calc((100vh - 170px) * var(--ar)));transform:none}
.hs.fs .hs-cap{width:min(100%,900px)}
.pwi.fs{justify-content:flex-start}
.pwi.fs .pwi-stage{width:min(100%,calc((100vh - 300px) * 2))}
.pwi.fs .pwi-controls,.pwi.fs .pwi-live,.pwi.fs .pwi-notice,.pwi.fs .pwi-predict{width:min(100%,900px)}
body.fs-lock{overflow:hidden}
@media print{.fs-btn{display:none!important}}

.m-media{min-width:0}
.m-media .try{margin-top:14px}
.m-media .pwi{margin-top:10px}
.rw-h{margin-top:16px}
.rw-links{list-style:none;padding:0;margin:4px 0 0}
.rw-links li{padding:8px 0;border-bottom:1px solid var(--line);font-size:1.05rem}
.rw-links small{color:var(--muted);margin-left:6px}
.sdg{margin:16px 0 0;font-size:1rem;color:var(--ink);background:var(--bg2);border-radius:6px;padding:10px 14px}

.m-main.with-fig{align-items:start}

.hs-all{display:inline-flex;margin-top:10px;padding:6px 14px;border:0;border-radius:99px;background:var(--bg2);color:var(--ink);font:700 .9rem "Atkinson Hyperlegible",sans-serif;cursor:pointer;box-shadow:0 2px 0 var(--line)}
.hs-all[aria-pressed=true]{background:var(--mustard);color:#2a1d06}
.hs-label.all{box-shadow:0 1px 4px rgba(0,0,0,.28)}
.hs-path.all{display:block}

/* an apparatus diagram with many labels gets the full width, below the text */
.m-main.with-fig.wide{grid-template-columns:1fr}
.m-main.with-fig.wide .m-text{max-width:46em}
.m-main.with-fig.wide .m-text .steps{grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}

.why-sdg{display:block;margin-top:8px;padding-top:8px;border-top:1px dashed var(--line);font-size:.95rem}
.why-sdg small{color:var(--muted)}

.align{margin:6px 0 0;font-size:.95rem;opacity:.85;color:var(--hero-ink)}