:root{--bg:#f6f7fb;--surface:#fff;--text:#16202e;--muted:#5b6778;--line:#e2e6ee;--primary:#0b3d91;--accent:#d52b1e;--hero-from:#0b3d91;--hero-to:#1a6fd1;--soft:#eef3fc;--radius:14px;--shadow:0 1px 2px rgba(16,32,60,.06),0 8px 24px rgba(16,32,60,.07);--font-head:Georgia,'Times New Roman',serif;--font:system-ui,-apple-system,'Segoe UI',Roboto,Arial,sans-serif}
@media (prefers-color-scheme:dark){:root{--bg:#0e131b;--surface:#161d28;--text:#e8edf5;--muted:#9aa7b8;--line:#263142;--soft:#1b2433;--shadow:0 1px 2px rgba(0,0,0,.4),0 8px 24px rgba(0,0,0,.35)}}
*{box-sizing:border-box}html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font:17px/1.65 var(--font);-webkit-text-size-adjust:100%}
a{color:var(--primary);text-decoration-thickness:1px;text-underline-offset:3px}
@media (prefers-color-scheme:dark){a{color:#8fb8ff}}
h1,h2,h3{font-family:var(--font-head);line-height:1.2;margin:0 0 .5em;letter-spacing:-.01em}
h1{font-size:clamp(1.8rem,4.2vw,2.7rem)}h2{font-size:clamp(1.35rem,2.6vw,1.75rem)}h3{font-size:1.1rem}
.wrap{width:min(1120px,100% - 32px);margin-inline:auto}
.skip{position:absolute;left:-999px}.skip:focus{left:8px;top:8px;background:#fff;padding:8px 12px;z-index:99}
.muted{color:var(--muted)}
/* cabecera */
.top{position:sticky;top:0;z-index:20;background:color-mix(in srgb,var(--surface) 92%,transparent);backdrop-filter:saturate(1.4) blur(10px);border-bottom:1px solid var(--line)}
.bar{display:flex;align-items:center;gap:18px;min-height:64px;flex-wrap:wrap;padding-block:8px}
.logo{display:flex;align-items:center;gap:10px;font:700 1.2rem var(--font-head);color:var(--text);text-decoration:none}
.mark{display:grid;place-items:center;width:34px;height:34px;border-radius:9px;background:var(--primary);color:#fff;font:700 1.15rem var(--font-head)}
.nav{display:flex;gap:4px;flex:1;overflow-x:auto;scrollbar-width:none}
.nav a{padding:8px 12px;border-radius:8px;color:var(--text);text-decoration:none;font-size:.95rem;font-weight:500;white-space:nowrap}
.nav a:hover{background:var(--soft)}
.sbox{position:relative;width:210px}
.sbox input,.bigsearch input{width:100%;padding:10px 14px;border:1px solid var(--line);border-radius:10px;background:var(--surface);color:var(--text);font:inherit;font-size:.95rem}
.sres{position:absolute;top:calc(100% + 6px);left:0;right:0;min-width:300px;background:var(--surface);border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow);overflow:hidden;z-index:30}
.sbox .sres{left:auto;right:0}
.sres a{display:block;padding:10px 14px;color:var(--text);text-decoration:none;border-bottom:1px solid var(--line);font-size:.92rem}
.sres a:hover{background:var(--soft)}.sres small{display:block;color:var(--muted)}
@media (max-width:760px){.nav{order:3;flex-basis:100%}.sbox{flex:1;width:auto}.bar{gap:10px}}
/* hero */
.hero{background:linear-gradient(135deg,var(--hero-from),var(--hero-to));color:#fff;padding:clamp(40px,8vw,88px) 0 clamp(48px,8vw,96px);position:relative;overflow:hidden}
.hero:before{content:"";position:absolute;inset:0;background:radial-gradient(600px 300px at 85% 10%,rgba(255,255,255,.18),transparent 70%),radial-gradient(500px 280px at 5% 100%,rgba(255,255,255,.1),transparent 70%)}
.hero .wrap{position:relative}
.hero h1{max-width:18ch;font-size:clamp(2.1rem,5.5vw,3.6rem)}
.hero p{max-width:60ch;font-size:1.15rem;opacity:.95}
.bigsearch{display:flex;gap:8px;max-width:640px;margin:22px 0 14px;position:relative;flex-wrap:wrap}
.bigsearch input{flex:1;min-width:200px;padding:14px 18px;font-size:1.05rem;border-radius:12px}
.bigsearch .sres{top:calc(100% + 6px);width:100%}
.chips{display:flex;gap:8px;flex-wrap:wrap;margin:0}
.chip{display:inline-block;padding:7px 14px;border-radius:999px;background:rgba(255,255,255,.16);color:#fff;text-decoration:none;font-size:.9rem;border:1px solid rgba(255,255,255,.3);cursor:pointer;font-family:inherit}
.chip:hover{background:rgba(255,255,255,.28)}
.filters .chip{background:var(--surface);color:var(--text);border-color:var(--line)}
.filters .chip.on{background:var(--primary);color:#fff;border-color:var(--primary)}
.filters{display:flex;gap:8px;flex-wrap:wrap;margin-top:18px}
.btn{display:inline-block;padding:12px 22px;border-radius:12px;background:var(--accent);color:#fff;font:600 1rem var(--font);border:0;cursor:pointer;text-decoration:none}
.btn:hover{filter:brightness(1.08)}.btn.ghost{background:transparent;color:var(--primary);border:1px solid var(--line);padding:9px 16px;font-size:.9rem}
@media (prefers-color-scheme:dark){.btn.ghost{color:#8fb8ff}}
/* estadísticas */
.stats{display:flex;gap:12px;flex-wrap:wrap;margin-top:-34px;position:relative}
.stats div{flex:1;min-width:140px;background:var(--surface);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px 20px;text-align:center}
.stats strong{display:block;font:700 1.9rem var(--font-head);color:var(--primary)}.stats span{color:var(--muted);font-size:.9rem}
@media (prefers-color-scheme:dark){.stats strong{color:#8fb8ff}}
/* secciones y tarjetas */
.sec{padding-block:38px}.pagehead{padding-block:34px 6px}
.shead{display:flex;justify-content:space-between;align-items:baseline;gap:12px;margin-bottom:6px}.shead a{font-weight:600;text-decoration:none;white-space:nowrap}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(270px,1fr));gap:16px}
.card{display:flex;flex-direction:column;gap:6px;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:18px 20px;text-decoration:none;color:var(--text);transition:transform .15s,box-shadow .15s,border-color .15s}
.card:hover{transform:translateY(-2px);box-shadow:var(--shadow);border-color:color-mix(in srgb,var(--primary) 40%,var(--line))}
.card h3{margin:2px 0 0}.card p{margin:0;color:var(--muted);font-size:.93rem;line-height:1.5;flex:1}
.card .meta{font-size:.82rem;color:var(--muted);margin-top:6px}
.card .ico,.ico{font-size:1.7rem;line-height:1}
.badge{display:inline-block;align-self:flex-start;font-size:.74rem;font-weight:700;letter-spacing:.04em;text-transform:uppercase;color:var(--primary);background:var(--soft);padding:3px 10px;border-radius:999px;margin-bottom:6px}
@media (prefers-color-scheme:dark){.badge{color:#8fb8ff}}
.meta{color:var(--muted);font-size:.9rem}
/* artículo */
.art{max-width:780px;padding-block:28px 10px}
.crumbs{font-size:.85rem;color:var(--muted);margin-bottom:14px}.crumbs a{color:var(--muted)}
.lead{font-size:1.2rem;color:var(--muted);margin:.3em 0 .6em}
.prose h2{margin-top:1.8em}.prose h3{margin-top:1.4em}
.prose p,.prose li{font-size:1.05rem}.prose ul,.prose ol{padding-left:1.3em}.prose li{margin:.3em 0}
.toc{background:var(--soft);border-radius:var(--radius);padding:14px 20px;margin:18px 0}
.toc ol{margin:.5em 0 0;padding-left:1.2em}.toc li{margin:.2em 0;font-size:.97rem}
.callout{border-left:4px solid var(--accent);background:var(--soft);padding:14px 18px;border-radius:0 var(--radius) var(--radius) 0;margin:1.2em 0}
.tbl{overflow-x:auto;margin:1.2em 0;border:1px solid var(--line);border-radius:12px}
table{border-collapse:collapse;width:100%;font-size:.95rem}th,td{padding:10px 14px;text-align:left;border-bottom:1px solid var(--line)}th{background:var(--soft);font-weight:700}tr:last-child td{border-bottom:0}
.cta{display:flex;gap:16px;align-items:center;justify-content:space-between;flex-wrap:wrap;background:linear-gradient(135deg,var(--hero-from),var(--hero-to));color:#fff;border-radius:var(--radius);padding:20px 24px;margin:28px 0}
.cta p{margin:.2em 0 0;opacity:.92}.cta .btn{background:#fff;color:var(--primary)}
.aviso{font-size:.82rem;color:var(--muted);border-top:1px solid var(--line);padding-top:14px;margin-top:28px}
.about{padding-bottom:40px}
/* calculadora */
.calc{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:20px;align-items:start;margin-top:18px}
@media (max-width:860px){.calc{grid-template-columns:1fr}}
.cform,.cres{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow)}
.cres{position:sticky;top:84px}@media (max-width:860px){.cres{position:static}}
.cform h2,.cres h2{font-size:1.15rem}
.f{display:block;margin-bottom:14px}.f>span{display:block;font-weight:600;font-size:.92rem;margin-bottom:5px}.f small{display:block;color:var(--muted);font-size:.8rem;margin-top:4px}
.inp{display:flex;align-items:center;border:1px solid var(--line);border-radius:10px;background:var(--bg);overflow:hidden}
.inp:focus-within,select:focus{outline:2px solid var(--primary);outline-offset:1px}
.inp i{font-style:normal;color:var(--muted);padding:0 12px;font-size:.92rem;white-space:nowrap}
.inp input{flex:1;min-width:0;border:0;background:transparent;color:var(--text);font:inherit;padding:11px 12px;outline:0}
select{width:100%;padding:11px 12px;border:1px solid var(--line);border-radius:10px;background:var(--bg);color:var(--text);font:inherit}
.rmain{background:var(--soft);border-radius:12px;padding:16px 18px;margin-bottom:14px}.rmain span{display:block;color:var(--muted);font-size:.9rem}.rmain strong{font:700 clamp(1.7rem,4vw,2.3rem) var(--font-head);color:var(--primary);word-break:break-word}
@media (prefers-color-scheme:dark){.rmain strong{color:#8fb8ff}}
.rrows{margin:0}.rrows div{display:flex;justify-content:space-between;gap:12px;padding:9px 0;border-bottom:1px solid var(--line)}.rrows dt{color:var(--muted)}.rrows dd{margin:0;font-weight:600;text-align:right}
.rnote{font-size:.85rem;color:var(--muted);margin-top:12px}.rerr{color:var(--accent);font-weight:600}
.rtable{max-height:320px;overflow:auto;margin-top:14px}
.faq{border:1px solid var(--line);border-radius:12px;padding:12px 16px;margin:10px 0;background:var(--surface)}.faq summary{cursor:pointer;font-weight:600}.faq p{margin:.6em 0 0}
/* cursos */
.lessons{list-style:none;padding:0;margin:0;display:grid;gap:10px}
.lessons a{display:flex;gap:14px;align-items:center;background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:14px 18px;text-decoration:none;color:var(--text)}
.lessons a:hover{border-color:var(--primary)}.lessons small{display:block;color:var(--muted)}.lessons .meta{margin-left:auto;white-space:nowrap}
.num{display:grid;place-items:center;flex:none;width:36px;height:36px;border-radius:50%;background:var(--primary);color:#fff;font-weight:700}
/* pie */
.foot{background:var(--surface);border-top:1px solid var(--line);margin-top:40px;padding-top:34px}
.fgrid{display:grid;grid-template-columns:2fr 1.4fr 1fr;gap:28px}@media (max-width:760px){.fgrid{grid-template-columns:1fr}}
.foot h3{font:700 .95rem var(--font);text-transform:uppercase;letter-spacing:.05em;color:var(--muted)}
.foot ul{list-style:none;padding:0;margin:0;columns:2;font-size:.93rem}.foot li{margin:.35em 0}.foot a{text-decoration:none}
.legal{border-top:1px solid var(--line);margin-top:26px;padding-block:18px;font-size:.82rem;color:var(--muted)}.legal p{margin:.3em 0}
@media print{.top,.foot,.cta,.sbox,.btn{display:none}}