/* AlTiro — limpio, preciso, un solo acento azul. Claro y oscuro con tokens propios. */
:root{--bg:#fafafa;--card:#fff;--text:#0a0a0a;--muted:#55606f;--line:#e4e7ec;--rule:#0a0a0a;--brand:#1d4ed8;--brand-ink:#fff;--ok:#0a0a0a;--tint:#f1f4f9;--field:#fff;color-scheme:light}
@media (prefers-color-scheme:dark){:root:not([data-theme=light]){--bg:#0a0d14;--card:#111620;--text:#eef1f6;--muted:#9aa4b5;--line:#232b39;--rule:#eef1f6;--brand:#6ea0ff;--brand-ink:#06101f;--ok:#eef1f6;--tint:#151b27;--field:#0d121a;color-scheme:dark}}
:root[data-theme=dark]{--bg:#0a0d14;--card:#111620;--text:#eef1f6;--muted:#9aa4b5;--line:#232b39;--rule:#eef1f6;--brand:#6ea0ff;--brand-ink:#06101f;--ok:#eef1f6;--tint:#151b27;--field:#0d121a;color-scheme:dark}
:root[data-theme=light]{color-scheme:light}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font:16px/1.65 Inter,"Segoe UI",system-ui,-apple-system,Roboto,"Helvetica Neue",sans-serif;-webkit-font-smoothing:antialiased;font-feature-settings:"cv11","ss01"}
a{color:var(--brand);text-underline-offset:3px}
a:hover{text-decoration-thickness:2px}
.wrap{max-width:1040px;margin:0 auto;padding:0 24px}
main.wrap{padding-bottom:24px}
main>p,main>ul,main>ol,main>details,main>h2,main>h1,main>.lead,main>.badge,main>.disc{max-width:720px}
/* Cabecera */
header.site{background:var(--bg);border-bottom:1px solid var(--line)}
header.site .wrap{display:flex;gap:20px;align-items:center;justify-content:space-between;padding:12px 24px;flex-wrap:wrap}
header.site a.logo{font-weight:800;font-size:1.3rem;letter-spacing:-.03em;color:var(--text);text-decoration:none;display:inline-flex;align-items:center;gap:9px}
.mark{width:26px;height:26px}
.mark rect{fill:var(--brand)}
.mark path{fill:var(--brand-ink)}
header.site nav{display:flex;flex-wrap:wrap;gap:0 2px;align-items:center}
header.site nav a{padding:8px 11px;min-height:40px;display:inline-flex;align-items:center;text-decoration:none;font-size:.9rem;font-weight:500;color:var(--muted);border-radius:8px}
header.site nav a:hover{color:var(--text);background:var(--tint)}
header.site nav a[aria-current=page]{color:var(--text);font-weight:650;background:var(--tint)}
.theme{margin-left:8px;width:40px;height:40px;min-height:40px;padding:0;display:inline-grid;place-items:center;background:transparent;color:var(--text);border:1px solid var(--line);border-radius:8px}
.theme:hover{background:var(--tint);color:var(--text)}
.theme svg{width:18px;height:18px;display:none}
.theme[data-state=auto] .i-auto,.theme[data-state=light] .i-light,.theme[data-state=dark] .i-dark{display:block}
/* Tipografía */
h1,h2{font-weight:750;letter-spacing:-.03em}
h1{font-size:clamp(1.9rem,4.4vw,2.7rem);line-height:1.12;margin:44px 0 12px}
h2{font-size:1.4rem;line-height:1.25;margin:52px 0 12px}
.lead{color:var(--muted);font-size:1.12rem;margin:0 0 22px}
.badge{display:block;font-size:.8rem;color:var(--muted);margin:0 0 26px}
/* Portada */
.hero{padding:60px 0 28px}
.hero h1{font-size:clamp(2.4rem,6.5vw,4.2rem);line-height:1.04;letter-spacing:-.045em;margin:0 0 18px;max-width:16ch}
.hero h1 em{font-style:normal;color:var(--brand)}
.hero .lead{font-size:1.2rem;max-width:48ch;color:var(--muted)}
.meta{margin:0 0 20px;display:inline-block;font-size:.78rem;font-weight:650;letter-spacing:.02em;color:var(--brand);background:var(--tint);border:1px solid var(--line);padding:5px 12px;border-radius:999px}
/* Índice numerado */
.grid{display:block;margin:12px 0 0;border-top:1px solid var(--line);counter-reset:n}
.grid a{counter-increment:n;position:relative;display:grid;grid-template-columns:3rem 1fr;column-gap:8px;padding:20px 44px 20px 0;border-bottom:1px solid var(--line);text-decoration:none;color:var(--text);transition:background .15s,padding-left .15s}
.grid a::before{content:counter(n,decimal-leading-zero);grid-row:1/3;font:600 .85rem/2 ui-monospace,"SF Mono","Cascadia Mono",Consolas,monospace;color:var(--muted);font-variant-numeric:tabular-nums}
.grid a::after{content:"→";position:absolute;right:8px;top:18px;font-size:1.2rem;color:var(--brand);opacity:0;transition:.15s}
.grid a:hover{background:var(--tint);padding-left:10px}
.grid a:hover::after{opacity:1;right:14px}
.grid a:hover::before{color:var(--brand)}
.grid a strong{display:block;font-size:1.12rem;font-weight:650;letter-spacing:-.015em;color:var(--text)}
.grid a span{display:block;font-size:.93rem;color:var(--muted);line-height:1.5;margin-top:2px}
/* Calculadora */
.card{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:24px}
.calc{display:grid;grid-template-columns:minmax(0,1.05fr) minmax(0,1fr);gap:20px;align-items:start;margin-top:8px}
@media (max-width:860px){.calc{grid-template-columns:1fr}}
#out{margin:0;position:sticky;top:20px;background:var(--tint)}
#out:empty{display:none}
@media (max-width:860px){#out{position:static}}
form .f{margin-bottom:18px}
label{display:block;font-weight:600;font-size:.86rem;margin-bottom:6px}
input,select,textarea{width:100%;padding:11px 12px;font:inherit;color:var(--text);background:var(--field);border:1px solid var(--line);border-radius:8px;transition:border-color .12s,box-shadow .12s}
input:hover,select:hover,textarea:hover{border-color:var(--muted)}
input:focus,select:focus,textarea:focus{outline:0;border-color:var(--brand);box-shadow:0 0 0 3px color-mix(in srgb,var(--brand) 28%,transparent)}
input[type=checkbox]{width:20px;height:20px;min-height:0;margin-right:10px;accent-color:var(--brand)}
.chk label{font-weight:400;display:flex;align-items:center;font-size:1rem}
.hint{font-size:.82rem;color:var(--muted);margin-top:5px}
.row2{display:grid;grid-template-columns:1fr 1fr;gap:12px}
@media (max-width:520px){.row2{grid-template-columns:1fr}}
button{background:var(--brand);color:var(--brand-ink);border:0;border-radius:8px;padding:12px 22px;font:inherit;font-weight:650;cursor:pointer;transition:filter .12s}
button:hover{filter:brightness(1.1)}
button:disabled{opacity:.6;cursor:default}
/* Resultados */
table.res{width:100%;border-collapse:collapse}
table.res th{text-align:left;font-weight:400;color:var(--muted);padding:11px 0;border-bottom:1px solid var(--line)}
table.res td{text-align:right;padding:11px 0;border-bottom:1px solid var(--line);font-variant-numeric:tabular-nums;white-space:nowrap;font-weight:600}
table.res tr.total th{color:var(--text);font-weight:650;border-bottom:0;padding-top:20px;font-size:.9rem}
table.res tr.total td{font-size:2rem;font-weight:750;letter-spacing:-.035em;color:var(--text);border-bottom:0;padding-top:16px;line-height:1.1}
.note{font-size:.83rem;color:var(--muted);margin:14px 0 0;line-height:1.5}
/* Contenido */
details{border-bottom:1px solid var(--line);padding:0;margin:0}
summary{cursor:pointer;font-weight:650;padding:16px 0}
details p{margin:0 0 16px;color:var(--muted)}
.ad{min-height:0;margin:24px 0}
.disc{border:0;border-left:3px solid var(--brand);padding:2px 0 2px 16px;font-size:.88rem;color:var(--muted);margin:32px 0}
footer{margin-top:64px;padding:10px 0 44px;border-top:1px solid var(--line);color:var(--muted);font-size:.88rem}
footer a{color:var(--muted)}
footer a:hover{color:var(--brand)}
[hidden]{display:none!important}
/* Accesibilidad */
.skip{position:absolute;left:-9999px;top:0;background:var(--brand);color:var(--brand-ink);padding:10px 16px;z-index:50;font-weight:700;border-radius:0 0 8px 0}
.skip:focus{left:0}
:focus-visible{outline:3px solid var(--brand);outline-offset:2px}
main:focus{outline:0}
button,input,select,textarea{min-height:44px}
input[type=checkbox]{min-height:0}
.theme{min-height:40px}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
@media (max-width:700px){
header.site .wrap{flex-wrap:wrap;gap:6px 12px;padding:10px 16px}
header.site a.logo{order:1}
.theme{order:2;margin-left:auto}
header.site nav{order:3;width:100%;flex-wrap:nowrap;overflow-x:auto;margin:0 -16px;padding:0 16px;scrollbar-width:none}
header.site nav::-webkit-scrollbar{display:none}
header.site nav a{white-space:nowrap;flex:none}
.wrap{padding:0 16px}
}

/* Errores de validación */
:root{--err:#b42318;--err-bg:#fef3f2}
@media (prefers-color-scheme:dark){:root:not([data-theme=light]){--err:#ff9b8f;--err-bg:#2a1512}}
:root[data-theme=dark]{--err:#ff9b8f;--err-bg:#2a1512}
.err{color:var(--text)}
.err strong{display:block;color:var(--err);margin-bottom:6px}
.err ul{margin:0;padding-left:20px}
.err li{margin:4px 0}
#out:has(.err){background:var(--err-bg);border-color:var(--err)}
input[aria-invalid=true],select[aria-invalid=true]{border-color:var(--err);box-shadow:0 0 0 3px color-mix(in srgb,var(--err) 25%,transparent)}
/* Impresión: solo el contenido útil */
@media print{
header.site,footer,.skip,form,.theme,nav,.grid,.ad{display:none!important}
body{background:#fff;color:#000}
#out{position:static;background:none;border:0;padding:0}
a{color:#000;text-decoration:none}
}

/* Ayudas de lectura */
.toc{margin:22px 0 4px;max-width:720px;padding:16px 18px;border:1px solid var(--line);border-radius:12px;background:var(--card)}
.toc strong{display:block;font-size:.85rem;margin-bottom:6px}
.toc ul{margin:0;padding-left:18px;columns:2;column-gap:28px}
@media (max-width:620px){.toc ul{columns:1}}
.toc li{margin:3px 0;font-size:.93rem;break-inside:avoid}
.reportar{margin:28px 0 0;padding:12px 16px;border-left:3px solid var(--brand);font-size:.9rem;color:var(--muted);max-width:720px}
.acciones{margin:16px 0 0}
button.ghost{background:transparent;color:var(--text);border:1px solid var(--line);padding:8px 14px;font-weight:600;font-size:.88rem;border-radius:8px;min-height:40px}
button.ghost:hover{background:var(--tint);filter:none;transform:none}
.copiado{font-size:.85rem;color:var(--muted);margin-left:8px}
h2[id]{scroll-margin-top:16px}
@media print{.toc,.reportar,.acciones{display:none!important}}
.lang-switch{margin-left:6px;min-width:40px;height:40px;display:inline-flex;align-items:center;justify-content:center;padding:0 10px;border:1px solid var(--line);border-radius:8px;color:var(--text);font-weight:700;font-size:.82rem;letter-spacing:.04em;text-decoration:none}
.lang-switch:hover{background:var(--tint);color:var(--brand)}
@media (max-width:700px){.lang-switch{order:2;margin-left:auto}.lang-switch+.theme{margin-left:6px}}
@media print{.lang-switch{display:none!important}}