:root{--azul:#0B1F3A;--azul2:#123058;--esm:#10B981;--amb:#F5A524;--gris:#E6EAF0;--txt:#1F2937;--fondo:#FFFFFF;--suave:#F5F7FA;--borde:#E1E6EE;--rojo:#D64545}
@media (prefers-color-scheme:dark){:root{--txt:#E6EAF0;--fondo:#0B1424;--suave:#101C32;--borde:#22314D}}
*{box-sizing:border-box}
html{font-family:Inter,system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif;color:var(--txt);background:var(--fondo);line-height:1.6}
body{margin:0}
.cont{max-width:1040px;margin:0 auto;padding:0 16px}
.estrecho{max-width:760px}
img{max-width:100%;height:auto}
a{color:#0a7f5a}
@media (prefers-color-scheme:dark){a{color:#34d399}}
h1,h2,h3{font-family:Oswald,Impact,"Arial Narrow",sans-serif;line-height:1.15;letter-spacing:.01em}
h1{font-size:clamp(2rem,6vw,3.2rem);margin:.6em 0 .3em}
h2{font-size:clamp(1.4rem,4vw,1.9rem);margin:1.6em 0 .5em}
h3{font-size:1.2rem;margin:.2em 0 .4em}
.salto{position:absolute;left:-999px}.salto:focus{left:8px;top:8px;background:#fff;color:#000;padding:8px;z-index:9}
.cab{background:var(--azul);color:#fff;position:sticky;top:0;z-index:5}
.fila{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap;padding-top:8px;padding-bottom:8px}
.marca{display:flex;align-items:center;gap:10px;color:#fff;text-decoration:none;font-family:Oswald,sans-serif;letter-spacing:.08em}
.marca b{color:var(--esm)}
.cab nav{display:flex;gap:4px 16px;flex-wrap:wrap}
.cab nav a{color:#dbe4f0;text-decoration:none;padding:6px 2px;border-bottom:2px solid transparent}
.cab nav a:hover,.cab nav a[aria-current]{color:#fff;border-bottom-color:var(--esm)}
.hero{background:radial-gradient(circle at 50% 30%,var(--azul2),var(--azul) 70%);color:#fff;padding:56px 0 64px}
.hero h1 span{color:var(--esm)}
.hero .lead{color:#dbe4f0}
.lead{font-size:1.15rem;max-width:62ch}
.etiqueta{display:inline-block;font-size:.8rem;text-transform:uppercase;letter-spacing:.1em;color:var(--esm);font-weight:600;margin:0}
.etiqueta a{color:inherit}
.acciones{display:flex;gap:12px;flex-wrap:wrap;margin:24px 0}
.btn,button{display:inline-block;background:var(--esm);color:var(--azul);font:700 1rem Inter,sans-serif;border:0;border-radius:10px;padding:12px 22px;text-decoration:none;cursor:pointer}
.btn:hover,button:hover{filter:brightness(1.08)}
.btn.sec{background:transparent;color:inherit;border:2px solid currentColor}
.btn.off{background:var(--borde);color:#6b7280;cursor:not-allowed}
:focus-visible{outline:3px solid var(--amb);outline-offset:2px}
.rejilla{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:16px;margin:16px 0}
.tarj{background:var(--suave);border:1px solid var(--borde);border-radius:14px;padding:18px;color:inherit;text-decoration:none;display:block}
.tarj.enlace:hover{border-color:var(--esm)}
.tarj p{margin:.3em 0 0}
.banda{background:var(--suave);border-block:1px solid var(--borde);margin:40px 0;padding:8px 0 32px}
.nivel details{border:1px solid var(--borde);border-radius:12px;margin:10px 0;padding:6px 14px;background:var(--suave)}
.nivel summary{cursor:pointer;font-weight:600;padding:8px 0}
.nivel summary small{font-weight:400;opacity:.7;margin-left:8px}
.lecciones{padding-left:1.4em}
.lecciones li{padding:3px 0}
.pronto{opacity:.6}
.video{aspect-ratio:16/9;background:var(--azul);border-radius:14px;overflow:hidden;margin:20px 0;display:flex;align-items:center;justify-content:center;color:#dbe4f0}
.video iframe{width:100%;height:100%;border:0}
.video.vacio a{color:var(--esm)}
.transcripcion{border-left:4px solid var(--esm);padding-left:16px;max-width:68ch}
.fuentes li{margin:6px 0;word-break:break-word}
.paginado{display:flex;justify-content:space-between;gap:12px;margin:32px 0;flex-wrap:wrap}
.aviso{background:#fff7e6;color:#4a3300;border:1px solid var(--amb);border-radius:10px;padding:12px 14px;font-size:.92rem}
.peq{font-size:.85rem;opacity:.8}
.check{list-style:none;padding:0}.check li{padding:4px 0 4px 28px;position:relative}
.check li:before{content:"✓";position:absolute;left:0;color:var(--esm);font-weight:700}
.check.no li:before{content:"✕";color:var(--rojo)}
.suscribir{display:grid;gap:8px;max-width:460px;margin:16px 0}
.suscribir input[type=email],.calc input{width:100%;padding:12px;border:1px solid var(--borde);border-radius:8px;font:inherit;background:var(--fondo);color:var(--txt)}
.chk{display:flex;gap:8px;font-size:.85rem;align-items:flex-start}.chk input{margin-top:4px}
.trampa{position:absolute;left:-9999px}
.estado{min-height:1.4em;font-size:.95rem;margin:0}
.calc{background:var(--suave);border:1px solid var(--borde);border-radius:14px;padding:18px;margin:16px 0}
.calc label{display:block;font-weight:600;margin:12px 0 4px}
.cols{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:0 16px}
.calc button{margin-top:16px}
.resultado{margin-top:16px}
.resultado table{border-collapse:collapse;width:100%}
.resultado td{padding:8px;border-bottom:1px solid var(--borde)}.resultado td:last-child{text-align:right;font-weight:700}
.resultado .err{color:var(--rojo);font-weight:600}
.pie{background:var(--azul);color:#c9d4e5;margin-top:64px;padding:28px 0}
.pie .aviso{background:transparent;color:#c9d4e5;border-color:#3a4d6e}
.pie .enlaces{display:flex;gap:8px 18px;flex-wrap:wrap;margin:14px 0}.pie a{color:#fff}
@media (prefers-reduced-motion:no-preference){.btn,button,.tarj{transition:filter .15s,border-color .15s}}
.articulo h2{margin-top:1.8em}.articulo ul,.articulo ol{padding-left:1.3em}.articulo li{margin:6px 0}.articulo p{max-width:68ch}
.toc{background:var(--suave);border:1px solid var(--borde);border-radius:12px;padding:12px 18px;margin:18px 0}.toc ul{margin:6px 0 0;padding-left:1.2em}
.anuncio{margin:28px 0;text-align:center;min-height:90px}.anuncio small{display:block;opacity:.6}