/* Dirección A · Curvas de nivel.
   Idea: el vocabulario de la asignatura se convierte en un mapa topográfico; cada capítulo es una cota.
   Retícula asimétrica 2/3 + 1/3, ritmo por capítulos, serif de lectura para las definiciones. */
:root{
  --paper:#f3f5fb;
  --surface:#ffffff;
  --ink:#0e1a3d;
  --ink-soft:#4a5578;
  --line:#d5dbee;
  --cobalt:#2347e0;
  --cobalt-ink:#ffffff;
  --cobalt-wash:#e3e9fd;
  --lime:#c8f04d;
  --lime-ink:#1b2800;
  --orange:#c2410c;
  --orange-wash:#ffe9de;
  --amber-wash:#fff1bf;
  --amber-ink:#6b4b00;
  --contour:rgba(35,71,224,.20);
  --contour-strong:rgba(232,86,26,.55);
  --f-display:"Bricolage Grotesque","Segoe UI",system-ui,sans-serif;
  --f-read:"Newsreader",Georgia,"Times New Roman",serif;
  --f-mono:"IBM Plex Mono",ui-monospace,Menlo,monospace;
  --gutter:clamp(16px,4vw,40px);
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --paper:#0a1130;--surface:#121c45;--ink:#e9eeff;--ink-soft:#9aa7d6;--line:#26346b;
  --cobalt:#8aa2ff;--cobalt-ink:#0a1130;--cobalt-wash:#1b2a66;
  --orange:#ff9566;--orange-wash:#3a2230;--amber-wash:#3a3313;--amber-ink:#ffd866;
  --contour:rgba(138,162,255,.20);--contour-strong:rgba(255,149,102,.5);
  color-scheme:dark}}
:root[data-theme="dark"]{
  --paper:#0a1130;--surface:#121c45;--ink:#e9eeff;--ink-soft:#9aa7d6;--line:#26346b;
  --cobalt:#8aa2ff;--cobalt-ink:#0a1130;--cobalt-wash:#1b2a66;
  --orange:#ff9566;--orange-wash:#3a2230;--amber-wash:#3a3313;--amber-ink:#ffd866;
  --contour:rgba(138,162,255,.20);--contour-strong:rgba(255,149,102,.5);
  color-scheme:dark}

*{box-sizing:border-box}
[hidden]{display:none!important}
html,body{margin:0}
body{background:var(--paper);color:var(--ink);font:400 1rem/1.55 var(--f-display);
  padding-bottom:calc(5.5rem + env(safe-area-inset-bottom,0px));-webkit-text-size-adjust:100%}
h1,h2,h3,p{margin:0}
button,input{font:inherit;color:inherit}
button{cursor:pointer}
:focus-visible{outline:3px solid var(--cobalt);outline-offset:2px}
.skip{position:absolute;left:-999px;top:8px;background:var(--lime);color:var(--lime-ink);padding:.5rem .8rem;border-radius:8px;z-index:20}
.skip:focus{left:8px}
.mono{font-family:var(--f-mono);font-size:.74rem;letter-spacing:.1em;text-transform:uppercase;color:var(--ink-soft)}
.shell{width:100%;max-width:74rem;margin-inline:auto;padding-inline:var(--gutter)}

/* barra superior y navegación */
.top{border-bottom:1px solid var(--line);background:var(--paper)}
.top .shell{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:60px}
.brand{font-weight:800;font-size:1.25rem;letter-spacing:-.02em;white-space:nowrap}
.brand{display:flex;align-items:center;gap:9px}
.logo{width:30px;height:30px;border-radius:7px;flex:none}
.logo-big{width:64px;height:64px;border-radius:14px;align-self:flex-start;box-shadow:0 6px 0 var(--ink);margin-bottom:8px}
.logo-foot{width:28px;height:28px;border-radius:6px;align-self:flex-start}
.brand b{background:var(--lime);color:var(--lime-ink);padding:0 .25em;border-radius:4px}
.tabnav{display:flex;gap:6px}
.tabnav button{border:0;background:none;padding:.6rem .95rem;border-radius:10px;font-weight:600;min-height:44px;color:var(--ink-soft)}
.tabnav button[aria-current="page"]{background:var(--ink);color:var(--paper)}
@media (max-width:700px){
  .tabnav{position:fixed;left:0;right:0;bottom:0;z-index:10;justify-content:center;gap:8px;background:var(--surface);
    border-top:1px solid var(--line);padding:8px var(--gutter) calc(8px + env(safe-area-inset-bottom,0px))}
  .tabnav button{flex:1;text-align:center}
  .brand{font-size:1.1rem}
}

/* portada */
.hero{position:relative;overflow:hidden;border-bottom:1px solid var(--line)}
.hero canvas{position:absolute;inset:0;width:100%;height:100%;display:block}
.hero-in{position:relative;padding-block:clamp(40px,8vw,96px) clamp(36px,6vw,64px);display:flex;flex-direction:column;gap:20px}
.hero h1{font-weight:800;font-size:clamp(2.7rem,9.5vw,6.6rem);line-height:.95;letter-spacing:-.035em;text-wrap:balance;max-width:14ch}
.hero h1 mark{background:var(--lime);color:var(--lime-ink);padding:0 .12em;border-radius:6px}
.hero p.lead{font:400 clamp(1.1rem,2.2vw,1.45rem)/1.5 var(--f-read);max-width:34em;color:var(--ink)}

/* disposición 2/3 + 1/3 */
.cols{display:grid;grid-template-columns:minmax(0,2fr) minmax(0,1fr);gap:clamp(24px,4vw,56px);padding-block:clamp(28px,5vw,56px)}
.cols>aside{align-self:start;position:sticky;top:16px}
@media (max-width:860px){.cols{grid-template-columns:minmax(0,1fr)}.cols>aside{position:static}}
.stack{display:flex;flex-direction:column;gap:clamp(28px,4vw,44px)}
.sec-h{display:flex;align-items:baseline;justify-content:space-between;gap:12px;flex-wrap:wrap}
.sec-h h2{font-weight:700;font-size:clamp(1.3rem,2.6vw,1.8rem);letter-spacing:-.02em}
.step{font:500 .8rem var(--f-mono);color:var(--cobalt);margin-right:.5em}
.linkbtn{background:none;border:0;color:var(--cobalt);text-decoration:underline;text-underline-offset:3px;padding:.4rem 0;min-height:44px;font-weight:600}

/* temas */
.chapters{display:grid;grid-template-columns:repeat(auto-fill,minmax(min(100%,19rem),1fr));gap:10px;margin-top:14px}
.chap{display:grid;grid-template-columns:2.6rem minmax(0,1fr) auto;gap:14px;align-items:center;padding:16px 18px;
  background:var(--surface);border:2px solid var(--line);border-radius:14px;cursor:pointer;min-height:68px}
.chap:has(input:checked){border-color:var(--cobalt);background:var(--cobalt-wash)}
.chap:has(input:focus-visible){outline:3px solid var(--cobalt);outline-offset:2px}
.chap input{position:absolute;opacity:0;pointer-events:none}
.chap .box{width:2.6rem;height:2.6rem;border-radius:10px;border:2px solid var(--ink-soft);display:grid;place-items:center;font:700 1rem var(--f-mono)}
.chap:has(input:checked) .box{background:var(--cobalt);border-color:var(--cobalt);color:var(--cobalt-ink)}
.chap .box::after{content:attr(data-n)}
.chap .nm{font-weight:700;font-size:1.25rem;letter-spacing:-.01em}
.chap .ct{font:500 .78rem var(--f-mono);color:var(--ink-soft);white-space:nowrap}
.seg{display:flex;flex-wrap:wrap;gap:8px;margin-top:14px}
.seg label{position:relative}
.seg input{position:absolute;opacity:0;inset:0;cursor:pointer;margin:0}
.seg span{display:block;min-width:4.4rem;padding:.75rem 1.1rem;border:2px solid var(--line);border-radius:12px;background:var(--surface);
  text-align:center;font:600 1.05rem var(--f-mono)}
.seg input:checked+span{background:var(--ink);border-color:var(--ink);color:var(--paper)}
.seg input:focus-visible+span{outline:3px solid var(--cobalt);outline-offset:2px}

/* panel lateral */
.panel{background:var(--surface);border:2px solid var(--ink);border-radius:18px;padding:22px;display:flex;flex-direction:column;gap:18px}
.bignum{font-weight:800;font-size:clamp(3.6rem,8vw,5.4rem);line-height:.9;letter-spacing:-.04em}
.bignum small{display:block;font:500 .85rem var(--f-mono);letter-spacing:0;color:var(--ink-soft);margin-top:10px;text-transform:none}
.opt{display:flex;gap:12px;align-items:flex-start;cursor:pointer;padding:6px 0}
.opt input{width:22px;height:22px;accent-color:var(--cobalt);flex:none;margin-top:2px}
.opt b{display:block;font-weight:600}
.opt span{display:block;font-size:.88rem;color:var(--ink-soft);line-height:1.4}
.btn{border:2px solid var(--ink);background:var(--surface);color:var(--ink);border-radius:12px;padding:.8rem 1.3rem;font-weight:700;min-height:50px;font-size:1rem}
.btn:hover{background:var(--cobalt-wash)}
.btn.go{background:var(--lime);border-color:var(--ink);color:var(--lime-ink);font-size:1.15rem;min-height:58px}
.btn.go:hover{background:#d6f56f}
.btn.blue{background:var(--cobalt);border-color:var(--cobalt);color:var(--cobalt-ink)}
.btn:disabled{opacity:.4;cursor:not-allowed}
.row{display:flex;flex-wrap:wrap;gap:10px;align-items:center}
.row.end{justify-content:space-between}
.note{font-size:.88rem;color:var(--ink-soft);max-width:60ch}

/* examen */
.examtop{position:sticky;top:0;z-index:5;background:var(--paper);border-bottom:1px solid var(--line);padding-top:env(safe-area-inset-top,0px)}
.examtop .shell{padding-block:12px;display:flex;flex-direction:column;gap:10px}
.meta{display:flex;justify-content:space-between;gap:10px;font:500 .85rem var(--f-mono);color:var(--ink-soft)}
.alt{height:8px;background:var(--line);border-radius:4px;position:relative}
.alt i{position:absolute;left:0;top:0;bottom:0;background:var(--cobalt);border-radius:4px;transition:width .25s}
.alt i::after{content:"";position:absolute;right:-5px;top:-4px;width:16px;height:16px;border-radius:50%;background:var(--lime);border:3px solid var(--ink)}
.qtag{align-self:flex-start;font:500 .74rem/1 var(--f-mono);letter-spacing:.1em;text-transform:uppercase;color:var(--cobalt);border:1.5px solid var(--cobalt);padding:.45rem .6rem;border-radius:6px}
.qdef{font:400 clamp(1.3rem,2.7vw,1.85rem)/1.55 var(--f-read);max-width:34em;hyphens:auto}
.blank{display:inline-block;min-width:3.4em;border-bottom:3px solid var(--orange);margin-inline:.12em;transform:translateY(-.12em)}
.ans-label{font:500 .74rem/1 var(--f-mono);letter-spacing:.1em;text-transform:uppercase;color:var(--ink-soft)}
.ans{width:100%;border:2px solid var(--ink);border-radius:12px;background:var(--surface);padding:.85rem 1rem;font:600 1.25rem var(--f-display);min-height:58px}
.ans:focus{border-color:var(--cobalt);outline:3px solid var(--cobalt-wash);outline-offset:0}
.pista{font:400 .85rem var(--f-mono);color:var(--ink-soft)}
.bank{border-top:1px dashed var(--line);padding-top:12px}
.bank summary{cursor:pointer;font-weight:600;color:var(--cobalt);min-height:44px;display:flex;align-items:center}
.chips{display:flex;flex-wrap:wrap;gap:6px;margin-top:6px}
.chip{border:1.5px solid var(--line);background:var(--paper);border-radius:999px;padding:.4rem .8rem;font-size:.9rem;min-height:40px}
.chip:hover{border-color:var(--cobalt)}
.chip.used{opacity:.35;text-decoration:line-through}
.dots{display:grid;grid-template-columns:repeat(auto-fill,minmax(2.5rem,1fr));gap:6px}
.dot{border:1.5px solid var(--line);background:var(--surface);border-radius:8px;min-height:40px;font:500 .8rem var(--f-mono)}
.dot.done{background:var(--cobalt-wash);border-color:var(--cobalt)}
.dot.cur{background:var(--ink);color:var(--paper);border-color:var(--ink)}
.confirm{background:var(--amber-wash);color:var(--amber-ink);border:2px solid var(--amber-ink);border-radius:12px;padding:14px 16px;display:flex;flex-direction:column;gap:10px}

/* resultados */
.score{position:relative;overflow:hidden;border-bottom:1px solid var(--line)}
.score canvas{position:absolute;inset:0;width:100%;height:100%}
.score-in{position:relative;padding-block:clamp(32px,6vw,64px);display:flex;flex-direction:column;gap:18px}
.nota{font-weight:800;font-size:clamp(5rem,18vw,10rem);line-height:.85;letter-spacing:-.05em}
.nota small{font-size:.28em;color:var(--ink-soft);letter-spacing:0;font-weight:600}
.det{font:500 1rem var(--f-mono);color:var(--ink)}
.bk{display:grid;gap:12px;margin-top:14px}
.bk-row{display:grid;grid-template-columns:minmax(0,12rem) 1fr 3.6rem;gap:12px;align-items:center}
.bk-row span{font-weight:600}
.bk-row b{font:600 .9rem var(--f-mono);text-align:right}
.bar{height:12px;background:var(--line);border-radius:6px;overflow:hidden}
.bar i{display:block;height:100%;background:var(--cobalt)}
.tabs{display:flex;flex-wrap:wrap;gap:8px}
.tab{border:2px solid var(--line);background:var(--surface);border-radius:999px;padding:.5rem 1.1rem;min-height:44px;font-weight:600}
.tab[aria-pressed="true"]{background:var(--ink);color:var(--paper);border-color:var(--ink)}
.rlist{display:flex;flex-direction:column;gap:14px}
.ritem{background:var(--surface);border:2px solid var(--line);border-left-width:8px;border-radius:12px;padding:16px 18px;display:flex;flex-direction:column;gap:8px;min-width:0}
.ritem.ok{border-left-color:var(--cobalt)}
.ritem.typo{border-left-color:#c79a00}
.ritem.no,.ritem.blank{border-left-color:var(--orange)}
.ritem header{display:flex;flex-wrap:wrap;justify-content:space-between;gap:8px;align-items:center}
.pill{font:600 .72rem/1 var(--f-mono);letter-spacing:.06em;text-transform:uppercase;padding:.4rem .6rem;border-radius:6px}
.ok .pill{background:var(--lime);color:var(--lime-ink)}
.typo .pill{background:var(--amber-wash);color:var(--amber-ink)}
.no .pill,.blank .pill{background:var(--orange-wash);color:var(--orange)}
.ritem h3{font-weight:700;font-size:1.3rem;letter-spacing:-.01em}
.ritem .def{font:400 1.05rem/1.6 var(--f-read);color:var(--ink-soft)}
.yours b{font-weight:700}

/* repaso */
.sbar{position:sticky;top:0;z-index:4;background:var(--paper);padding-block:12px;display:flex;flex-direction:column;gap:12px;border-bottom:1px solid var(--line)}
.search{width:100%;border:2px solid var(--ink);border-radius:12px;background:var(--surface);padding:.8rem 1rem;min-height:52px;font-size:1.05rem}
.search:focus{border-color:var(--cobalt);outline:3px solid var(--cobalt-wash)}
.slist{display:flex;flex-direction:column;gap:clamp(24px,4vw,40px);padding-block:24px}
.sgroup>h2{display:flex;gap:12px;align-items:baseline;font-weight:800;font-size:clamp(1.6rem,4vw,2.6rem);letter-spacing:-.03em;padding-bottom:12px;border-bottom:3px solid var(--ink)}
.term{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,2fr);gap:8px 32px;padding-block:20px;border-bottom:1px solid var(--line)}
.term h3{font-weight:700;font-size:1.3rem;line-height:1.2;letter-spacing:-.015em}
.term p{font:400 1.08rem/1.65 var(--f-read);max-width:46em}
.term mark{background:var(--lime);color:var(--lime-ink);border-radius:3px;padding-inline:2px}
@media (max-width:700px){.term{grid-template-columns:minmax(0,1fr)}}

.donate{display:flex;flex-wrap:wrap;gap:10px 16px;align-items:center;max-width:46em;font-size:.95rem;color:var(--ink-soft)}
.donate .btn{text-decoration:none;display:inline-flex;align-items:center}

/* perfil, puntos y tienda */
.me{display:flex;align-items:center;gap:8px;border:2px solid var(--ink);background:var(--surface);border-radius:999px;padding:4px 12px 4px 4px;min-height:44px;font-weight:700;cursor:pointer}
.me:hover{background:var(--cobalt-wash)}
.me-nick{max-width:9rem;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.me-bal{font:600 .85rem var(--f-mono);color:var(--cobalt)}
.av{display:inline-grid;place-items:center;width:34px;height:34px;border-radius:50%;font-weight:800;flex:none;border:2px solid var(--ink)}
.av.big{width:64px;height:64px;font-size:1.8rem}
@media (max-width:700px){.me-nick{display:none}}
.pts{display:flex;flex-direction:column;gap:6px;align-items:flex-start}
.pts b{font:800 clamp(2rem,6vw,3.2rem)/1 var(--f-display);letter-spacing:-.03em;color:var(--cobalt)}
.pts>span{font:500 .8rem var(--f-mono);text-transform:uppercase;letter-spacing:.08em}
.fb .pt{font:700 .9rem var(--f-mono);background:var(--ink);color:var(--paper);border-radius:999px;padding:.1rem .6rem;margin-left:.5rem}
.shop-body{display:flex;flex-direction:column;gap:22px;padding-bottom:24px}
.shop-top{display:flex;flex-wrap:wrap;gap:18px 32px;align-items:center;justify-content:space-between}
.shop-me{display:flex;gap:14px;align-items:center}
.shop-me h2{font-weight:800;font-size:1.6rem;letter-spacing:-.02em}
.shop-bal{display:flex;flex-direction:column;gap:2px}
.shop-bal b{font:800 2.6rem/1 var(--f-display);letter-spacing:-.03em;color:var(--cobalt)}
.shop-bal small{font:400 .8rem var(--f-mono);color:var(--ink-soft)}
.shop-how{border:2px solid var(--line);border-radius:12px;padding:12px 16px;background:var(--surface)}
.shop-how summary{font-weight:700;cursor:pointer}
.shop-how ul{margin:10px 0 0;padding-left:1.2rem;display:flex;flex-direction:column;gap:4px;color:var(--ink-soft)}
.shop-sec h2{font-weight:800;font-size:1.5rem;letter-spacing:-.02em;padding-bottom:10px;border-bottom:3px solid var(--ink);margin-bottom:14px}
.shop-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:12px}
.si{border:2px solid var(--ink);border-radius:14px;background:var(--surface);padding:14px;display:flex;flex-direction:column;gap:6px;align-items:flex-start}
.si.eq{background:var(--cobalt-wash);border-color:var(--cobalt)}
.si .mono{font:500 .78rem var(--f-mono);color:var(--ink-soft)}
.si small{font:400 .78rem var(--f-mono);color:var(--orange)}
.si .btn{margin-top:auto;min-height:44px;padding:.5rem 1rem;font-size:.95rem;align-self:stretch}
.si-prev{min-height:64px;display:flex;align-items:center}
.si-title{font-weight:800;font-size:1.05rem;background:var(--lime);color:var(--lime-ink);padding:.2rem .6rem;border-radius:6px}
.si-dots{display:flex;gap:4px}.si-dots i{width:16px;height:28px;border-radius:4px;display:block;transform:rotate(12deg);outline:1px solid var(--line)}
#nick{position:fixed;inset:0;z-index:60;background:rgba(14,26,61,.65);display:grid;place-items:center;padding:16px}
.nk-card{background:var(--surface);border:2px solid var(--ink);border-radius:18px;padding:24px;max-width:420px;width:100%;display:flex;flex-direction:column;gap:14px}
.nk-card h2{font-weight:800;font-size:1.6rem;letter-spacing:-.02em}
.nk-err{color:var(--orange);font-weight:600;min-height:1.4em}

/* libros */
.books{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:clamp(14px,3vw,24px);padding-block:8px 24px}
.book{border:2px solid var(--ink);border-radius:16px;background:var(--surface);padding:clamp(16px,3vw,24px);display:flex;flex-direction:column;gap:14px;justify-content:space-between}
.book h3{font-weight:800;font-size:clamp(1.3rem,3vw,1.7rem);line-height:1.15;letter-spacing:-.02em}
.book p{font:400 1.02rem/1.55 var(--f-read);color:var(--ink-soft)}
.book p.mono{font:500 .8rem var(--f-mono);color:var(--cobalt);margin-top:6px}
.book .btn{align-self:flex-start;text-decoration:none;display:inline-flex;align-items:center}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
@media (max-width:700px){.books{grid-template-columns:minmax(0,1fr)}}

footer{margin-top:24px;border-top:1px solid var(--line)}
footer .shell{padding-block:24px;display:flex;flex-direction:column;gap:6px}
@media (prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important;scroll-behavior:auto!important}}
@media (max-width:480px){.chap{grid-template-columns:2.4rem minmax(0,1fr);}.chap .ct{grid-column:2}.bk-row{grid-template-columns:minmax(0,7.5rem) 1fr 3.2rem}}

/* recompensa y motivación */
#cv-fx{position:fixed;inset:0;width:100vw;height:100vh;pointer-events:none;z-index:50}
.meta-line{font:500 .85rem var(--f-mono);color:var(--cobalt)}
.streak{font:700 .85rem var(--f-mono);color:var(--orange);background:var(--orange-wash);border-radius:999px;padding:.2rem .7rem}
.streak.pop{animation:pop .45s var(--ease,cubic-bezier(.22,1,.36,1))}
.fb{border:2px solid var(--ink);border-radius:12px;padding:12px 14px;font-weight:600;display:flex;flex-direction:column;gap:2px}
.fb small{font:400 .85rem var(--f-mono);color:var(--ink-soft)}
.fb.ok{background:var(--lime);color:var(--lime-ink);animation:pop .4s cubic-bezier(.22,1,.36,1)}
.fb.ok small{color:var(--lime-ink)}
.fb.typo{background:var(--amber-wash);color:var(--amber-ink);border-color:var(--amber-ink);animation:pop .4s cubic-bezier(.22,1,.36,1)}
.fb.typo small{color:var(--amber-ink)}
.fb.no{background:var(--orange-wash);color:var(--orange);border-color:var(--orange);animation:shake .35s}
.fb.no small{color:var(--orange)}
.ans[readonly]{background:var(--paper)}
.dot.hit{background:var(--lime);color:var(--lime-ink);border-color:var(--ink)}
.dot.miss{background:var(--orange-wash);border-color:var(--orange);color:var(--orange)}
.verdict{font:600 clamp(1.2rem,3vw,1.8rem)/1.25 var(--f-display);letter-spacing:-.02em;max-width:24em}
.nota.done{animation:pop .5s cubic-bezier(.22,1,.36,1)}
@keyframes pop{0%{transform:scale(.88);opacity:.2}60%{transform:scale(1.04);opacity:1}100%{transform:scale(1)}}
@keyframes shake{0%,100%{transform:translateX(0)}25%{transform:translateX(-6px)}75%{transform:translateX(6px)}}