:root{color-scheme:light;--paper:#f5f2eb;--card:#fffdf8;--ink:#172c32;--muted:#52666b;--rule:#c4cec9;--accent:#116353;--wash:#e6eee6;--error:#9e3630;--shadow:0 12px 36px #19302b0b;font-family:system-ui,sans-serif;line-height:1.6}
:root[data-theme=dark]{color-scheme:dark;--paper:#101b20;--card:#17272c;--ink:#e9f0e8;--muted:#b0c3c2;--rule:#415a5f;--accent:#8dd5bc;--wash:#223c3c;--error:#ffb4a7;--shadow:none}
*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink)}a{color:var(--accent)}button,input,select,textarea{font:inherit}button,a.button{cursor:pointer;border:1px solid var(--rule);border-radius:8px;padding:.65rem 1rem;background:var(--card);color:var(--ink);text-decoration:none;font-weight:650}button:hover,a.button:hover{border-color:var(--accent);background:var(--wash)}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid var(--accent);outline-offset:3px}.primary{background:var(--accent);color:var(--paper)}.topbar{display:flex;gap:.7rem;align-items:center;flex-wrap:wrap;padding:1rem max(1rem,calc((100vw - 1160px)/2));border-bottom:1px solid var(--rule);background:var(--card)}.topbar a{margin-right:auto}.topbar output{font-variant-numeric:tabular-nums;font-weight:700}.wrap{max-width:1160px;margin:auto;padding:2rem 1.2rem 4rem}header.hero{padding:1rem 0 2rem;max-width:940px}.eyebrow{text-transform:uppercase;letter-spacing:.12em;font-size:.78rem;font-weight:800;color:var(--accent)}h1{font-size:clamp(2.2rem,4vw,3.8rem);line-height:1.12;letter-spacing:-.045em;margin:.6rem 0 1rem}h2{font-size:1.65rem;line-height:1.25;margin:0 0 1rem}h3{line-height:1.35;margin:.1rem 0 .6rem}p{margin:.6rem 0 1rem}.lead{font-size:1.2rem;color:var(--muted)}.chips,.actions,.controls,.case-tabs{display:flex;gap:.6rem;flex-wrap:wrap;align-items:center}.chip{border:1px solid var(--rule);border-radius:100px;padding:.2rem .8rem;font-size:.85rem}.section{margin:1.5rem 0;padding:1.7rem;background:var(--card);border:1px solid var(--rule);border-radius:16px;box-shadow:var(--shadow);scroll-margin-top:1rem}nav.jump{display:flex;gap:1rem;flex-wrap:wrap;padding-bottom:1rem}nav.jump a{font-weight:650}.grid{display:grid;grid-template-columns:1fr 1fr;gap:1.4rem}.notice{border-left:4px solid var(--accent);padding:.6rem 1rem;background:var(--wash);border-radius:0 8px 8px 0}.small{font-size:.88rem;color:var(--muted)}.route{display:grid;grid-template-columns:repeat(5,1fr);gap:1rem;padding:0;list-style:none}.route li{border-top:3px solid var(--accent);padding-top:.6rem}.route strong{display:block}.figure-card{border:1px solid var(--rule);border-radius:12px;overflow:hidden}.figure-head,.figure-foot{padding:.85rem 1rem;display:flex;gap:1rem;justify-content:space-between;flex-wrap:wrap}.figure-head{border-bottom:1px solid var(--rule)}.figure-foot{border-top:1px solid var(--rule)}.figure-head small{letter-spacing:.08em}.figure-body{background:var(--paper)}.figure-body svg{width:100%;height:auto;display:block}.figure-card [data-part] .iso-solid{transition:opacity .35s ease,filter .35s ease}.figure-card [data-part][data-on=true] .iso-solid{filter:contrast(1.7);opacity:1}.figure-card [data-part][data-on=false] .iso-solid{opacity:.48}.controls{margin:1rem 0}.controls button[aria-pressed=true],.case-tabs button[aria-pressed=true]{border-color:var(--accent);box-shadow:inset 0 -3px var(--accent);background:var(--wash)}.controls label{display:flex;align-items:center;gap:.6rem}.controls select{max-width:100%;padding:.5rem}.readings{display:grid;grid-template-columns:repeat(3,1fr);gap:.7rem;margin:1rem 0}.reading{background:var(--wash);border-radius:9px;padding:.8rem;min-width:0}.reading>span{display:block;color:var(--muted);font-size:.85rem}.reading strong{font-size:1.1rem}.task{padding:1.3rem;border:1px solid var(--rule);border-radius:12px;margin:1rem 0;break-inside:avoid}.task[data-solved=true]{border-left:5px solid var(--accent)}.fields{display:flex;gap:1rem;flex-wrap:wrap;margin:1rem 0}.field{flex:1 1 180px;max-width:320px}.field label{display:block;font-weight:650;font-size:.9rem;margin-bottom:.3rem}.field input,.field select,textarea{width:100%;padding:.65rem;background:var(--paper);color:var(--ink);border:1px solid var(--rule);border-radius:7px;min-height:45px}.field input{font-variant-numeric:tabular-nums}textarea{min-height:110px;resize:vertical}.feedback{color:var(--error);font-weight:650;min-height:1.5em}.feedback.ok{color:var(--accent)}details{border-top:1px solid var(--rule);margin-top:1rem;padding-top:.7rem}summary{cursor:pointer;font-weight:650}.solution{background:var(--wash);padding:.8rem;border-radius:8px}.table-scroll{overflow-x:auto}table{border-collapse:collapse;width:100%}th,td{text-align:center;padding:.5rem;border-bottom:1px solid var(--rule)}th{background:var(--wash)}.mission{background:var(--wash);padding:1rem;border-radius:9px}.print-title{display:none}footer{margin-top:2rem;color:var(--muted)}.board-mode .wrap{font-size:1.18rem;max-width:1400px}.board-mode .task{padding:1.7rem}.board-mode .topbar{position:static}.katex-display{max-width:100%;overflow-x:auto;overflow-y:hidden}.diagram{display:block;padding:1rem;border:1px dashed var(--rule);border-radius:8px}.unit-note{display:block;font-size:.8rem;color:var(--muted)}.no-js{padding:1rem;border:2px solid var(--error)}
@media(max-width:720px){.grid{grid-template-columns:1fr}.section{padding:1rem}.wrap{padding:1.4rem .8rem}.route{grid-template-columns:1fr 1fr}.readings{grid-template-columns:1fr 1fr}.topbar{padding:.7rem}.topbar a{width:100%}.field{max-width:none}.figure-head,.figure-foot{font-size:.85rem}.board-mode .wrap{font-size:1rem}}@media(prefers-reduced-motion:reduce){*,*::before,*::after{transition:none!important;animation:none!important;scroll-behavior:auto!important}}
@page{size:A4;margin:14mm}@media print{ :root,:root[data-theme=dark]{color-scheme:light;--paper:#fff;--card:#fff;--ink:#000;--muted:#333;--rule:#aaa;--accent:#000;--wash:#f2f2f2}body{font-size:10pt}.wrap{padding:0;max-width:none}.topbar,.hero,nav.jump,.screen-only,footer,.task button,.feedback,.task details:not(.solution-details),#ruta,#teoria,#laboratori{display:none!important}.print-title{display:block}.section{border:0;padding:0;margin:5mm 0;box-shadow:none}.task{padding:4mm;margin:4mm 0;border-radius:0}.task[data-solved=true]{border:1px solid #aaa}.task .fields{gap:5mm;margin:3mm 0}.field{flex:1 1 40mm}.field input,.field select,textarea{background:#fff;border:0;border-bottom:1px solid #555;border-radius:0;color:transparent;box-shadow:none}.field input::placeholder,textarea::placeholder{color:transparent}.solution-details{display:none}.print-solutions .solution-details{display:block}.print-solutions .solution-details summary{display:none}.print-solutions .solution{background:#f4f4f4}.print-solutions .solution-details:not([open])>.solution{display:block}.grid{display:block}.mission{background:#fff;border:1px solid #aaa}.small{color:#333}h2{font-size:16pt}h3{font-size:12pt}.katex{font-size:1.05em}.print-title h1{font-size:23pt}.print-title p{margin:2mm 0}.answer-lines{height:16mm;border-bottom:1px solid #aaa}.task .feedback{display:none}.report textarea{height:25mm;min-height:25mm}}
/* Les peces es mantenen opaques: l’estat canvia el contorn, mai la geometria. */
.figure-card [data-part] .iso-solid{opacity:1!important;filter:none!important}.figure-card [data-part] .iso-line{transition:stroke .35s ease}.figure-card [data-part^=key][data-on=false] .iso-edge{stroke:var(--anatomy-mid)}.figure-card [data-part^=key][data-on=true] .iso-edge{stroke:var(--anatomy-hi)}.figure-card [data-part=output][data-on=true] .iso-top{fill:var(--anatomy-lit)}.figure-card [data-part=output] .iso-top{transition:fill .35s ease}

.figure-card.iso[data-theme=dark]{--anatomy-mid:#9aa5a4;--anatomy-lo:#626f70;--anatomy-faint:#3d4c50}
@media print{html[data-theme] body[data-lesson] .katex{color:#000!important}.task{padding:3mm;margin:3mm 0}.task .fields{margin:2mm 0}.field input,.field select{min-height:0;height:7mm;padding:1mm 0}.solution p.small{margin:1mm 0}.solution-details{padding-top:2mm;margin-top:2mm}.solution{padding:2mm}.report textarea{height:23mm;min-height:23mm}}
@media print{.report>.small{display:none}.task .fields{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:4mm}.field{min-width:0;max-width:none}.field label{white-space:normal}}