html{-webkit-text-size-adjust:100%}
body{margin:0}
[hidden]{display:none!important}
img{max-width:100%}

/* Layout: libro de cuentas — índice lateral fijo + mesa de trabajo (formulario | resultado) */
:root{
  --bg:#f3f6f4; --surface:#ffffff; --ink:#12241f; --muted:#5a6b65; --line:#dbe3df;
  --accent:#0d6e55; --accent-ink:#ffffff; --accent-soft:#e1f0ea; --mark:#c9e8dc;
  --warn:#9a5b00;
  --f-display:"Bricolage Grotesque", "Avenir Next", "Segoe UI", system-ui, sans-serif;
  --f-body:"Instrument Sans", "Helvetica Neue", "Segoe UI", system-ui, sans-serif;
  --f-num:"IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --bg:#0c1412; --surface:#13201c; --ink:#e4eeea; --muted:#93a59f; --line:#24352f;
    --accent:#4fd1a5; --accent-ink:#06231a; --accent-soft:#183a30; --mark:#1d4639; --warn:#f0b35c;
    color-scheme:dark;
  }
}
:root[data-theme="dark"]{
  --bg:#0c1412; --surface:#13201c; --ink:#e4eeea; --muted:#93a59f; --line:#24352f;
  --accent:#4fd1a5; --accent-ink:#06231a; --accent-soft:#183a30; --mark:#1d4639; --warn:#f0b35c;
  color-scheme:dark;
}
*{box-sizing:border-box}
body{background:var(--bg);color:var(--ink);font-family:var(--f-body);font-size:16px;line-height:1.55;
  padding-left:max(16px, env(safe-area-inset-left, 0px));padding-right:max(16px, env(safe-area-inset-right, 0px))}
a{color:var(--accent)}
.wrap{max-width:1160px;margin:0 auto}

/* Cabecera */
.top{display:flex;align-items:center;justify-content:space-between;gap:16px;padding-block:22px 18px;border-bottom:1px solid var(--line)}
.brand{display:flex;align-items:center;gap:12px;text-decoration:none;color:var(--ink)}
.mark{width:34px;height:34px;display:grid;grid-template-columns:1fr 1fr;gap:3px}
.mark i{background:var(--accent);border-radius:3px}
.mark i:nth-child(2){background:var(--mark)} .mark i:nth-child(3){background:var(--mark)}
.brand b{font-family:var(--f-display);font-size:1.6rem;letter-spacing:-.02em;font-weight:700}
.top p{margin:0;color:var(--muted);font-size:.92rem;max-width:34ch;text-align:right}

/* Estructura */
.shell{display:grid;grid-template-columns:230px minmax(0,1fr);gap:40px;padding-block:32px 48px}
nav.index{position:sticky;top:calc(env(safe-area-inset-top, 0px) + 20px);align-self:start;display:flex;flex-direction:column;gap:22px}
.group h2{font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);margin:0 0 8px;font-weight:600}
.group ul{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:2px}
.group a{text-decoration:none;cursor:pointer;display:flex;justify-content:space-between;align-items:center;width:100%;padding:8px 10px;border-radius:8px;font-weight:500;color:var(--ink);box-sizing:border-box}
.group a:hover{background:var(--accent-soft)}
.group a[aria-current="page"]{background:var(--ink);color:var(--bg)}
.group a:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.group a small{font-family:var(--f-num);font-size:.7rem;opacity:.6}

.ad{border:1px dashed var(--line);border-radius:10px;color:var(--muted);font-size:.72rem;letter-spacing:.1em;text-transform:uppercase;display:grid;place-items:center;text-align:center}
.ad.side{height:250px}
.ad.wide{height:100px;margin-block:8px}

/* Calculadora */
.eyebrow{font-family:var(--f-num);font-size:.78rem;color:var(--accent);letter-spacing:.04em}
.calc h1{font-family:var(--f-display);font-weight:700;font-size:clamp(1.9rem,4vw,2.7rem);letter-spacing:-.025em;line-height:1.08;margin:6px 0 10px;text-wrap:balance}
.lede{color:var(--muted);margin:0 0 26px;max-width:62ch;font-size:1.04rem}
.desk{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:0;border:1px solid var(--line);border-radius:16px;background:var(--surface);overflow:hidden}
form.fields{padding:24px;display:flex;flex-direction:column;gap:16px;border-right:1px solid var(--line)}
.field{display:flex;flex-direction:column;gap:6px;min-width:0}
.field label{font-weight:600;font-size:.9rem}
.field .hint{font-size:.8rem;color:var(--muted)}
.row2{display:grid;grid-template-columns:1fr 1fr;gap:14px}
input,select{font:inherit;color:var(--ink);background:var(--bg);border:1px solid var(--line);border-radius:10px;padding:10px 12px;width:100%;min-width:0}
input:focus-visible,select:focus-visible{outline:2px solid var(--accent);outline-offset:1px;border-color:var(--accent)}
.unit{position:relative}
.unit input{padding-right:42px;font-family:var(--f-num)}
.unit span{position:absolute;right:12px;top:50%;transform:translateY(-50%);color:var(--muted);font-size:.85rem;pointer-events:none}
.seg{display:flex;gap:6px;flex-wrap:wrap}
.seg label{flex:1;min-width:max-content}
.seg input{position:absolute;opacity:0;width:1px;height:1px}
.seg span{display:block;text-align:center;padding:9px 12px;border:1px solid var(--line);border-radius:10px;cursor:pointer;font-weight:500;font-size:.9rem;background:var(--bg)}
.seg input:checked+span{background:var(--ink);color:var(--bg);border-color:var(--ink)}
.seg input:focus-visible+span{outline:2px solid var(--accent);outline-offset:2px}

.result{padding:24px;display:flex;flex-direction:column;gap:16px;background:var(--accent-soft)}
.result .label{font-size:.78rem;letter-spacing:.1em;text-transform:uppercase;color:var(--muted);font-weight:600}
.big{font-family:var(--f-display);font-weight:700;font-size:clamp(2.2rem,5vw,3.1rem);letter-spacing:-.03em;line-height:1;font-variant-numeric:tabular-nums;color:var(--ink)}
.big small{font-size:.42em;font-family:var(--f-body);font-weight:500;color:var(--muted);letter-spacing:0}
.sub{color:var(--muted);font-size:.95rem;margin-top:-6px}
dl.ledger{margin:0;display:flex;flex-direction:column}
dl.ledger div{display:flex;justify-content:space-between;gap:12px;padding:8px 0;border-bottom:1px dotted var(--line)}
dl.ledger div:last-child{border-bottom:0}
dl.ledger dt{color:var(--muted);font-size:.92rem}
dl.ledger dd{margin:0;font-family:var(--f-num);font-size:.9rem;font-variant-numeric:tabular-nums;text-align:right;white-space:nowrap}
dl.ledger div.total{border-top:1px solid var(--ink);border-bottom:0;margin-top:4px;padding-top:10px}
dl.ledger div.total dt,dl.ledger div.total dd{color:var(--ink);font-weight:600}
.msg{font-size:.9rem;color:var(--warn);font-weight:500}
.bar{display:flex;height:12px;border-radius:6px;overflow:hidden;background:var(--line)}
.bar i{display:block;height:100%}
.bar i.a{background:var(--accent)} .bar i.b{background:var(--mark)}
.keys{display:flex;gap:16px;flex-wrap:wrap;font-size:.82rem;color:var(--muted)}
.keys span::before{content:"";display:inline-block;width:10px;height:10px;border-radius:3px;margin-right:6px;vertical-align:-1px;background:var(--mark)}
.keys span.a::before{background:var(--accent)}
svg.growth{width:100%;height:auto;display:block}
svg.growth text{fill:var(--muted);font-family:var(--f-num);font-size:11px}

.howto{max-width:68ch;margin-top:36px}
.howto h2{font-family:var(--f-display);font-size:1.35rem;letter-spacing:-.015em;margin:0 0 8px}
.howto p,.howto li{color:var(--ink);font-size:.98rem}
.howto ul{padding-left:20px}
.note{font-size:.82rem;color:var(--muted);border-left:3px solid var(--line);padding-left:12px;margin-top:18px}

.pct{display:flex;flex-direction:column;gap:12px}
.pct .line{display:flex;align-items:center;flex-wrap:wrap;gap:8px;font-size:.95rem}
.pct .line input{width:110px;font-family:var(--f-num)}
.pct output{font-family:var(--f-num);font-weight:600;background:var(--surface);border:1px solid var(--line);border-radius:8px;padding:6px 10px;min-width:90px;text-align:right}

footer{border-top:1px solid var(--line);padding-block:24px 36px;color:var(--muted);font-size:.85rem;display:flex;flex-wrap:wrap;gap:8px 24px;justify-content:space-between}
footer nav{display:flex;gap:18px;flex-wrap:wrap}
footer nav span{color:var(--ink)}

@media (max-width:900px){
  .shell{grid-template-columns:minmax(0,1fr);gap:24px;padding-top:16px}
  nav.index{position:static;flex-direction:row;overflow-x:auto;gap:8px;padding-bottom:6px;scrollbar-width:thin}
  .group{display:contents}
  .group h2{display:none}
  .group ul{flex-direction:row;gap:8px}
  .group a{white-space:nowrap;border:1px solid var(--line);background:var(--surface);padding:8px 12px}
  .group a small{display:none}
  .ad.side{display:none}
  .top p{display:none}
}
@media (max-width:680px){
  .desk{grid-template-columns:minmax(0,1fr)}
  form.fields{border-right:0;border-bottom:1px solid var(--line)}
}
@media (max-width:420px){ .row2{grid-template-columns:1fr} }
@media (prefers-reduced-motion:no-preference){
  .calc:not([hidden]){animation:rise .35s ease both}
  @keyframes rise{from{opacity:.4;transform:translateY(6px)}to{opacity:1;transform:none}}
}

.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}
/* Portada */
.hero{padding-block:8px 28px;max-width:62ch}
.hero h1{font-family:var(--f-display);font-weight:700;font-size:clamp(2rem,5vw,3.2rem);letter-spacing:-.03em;line-height:1.05;margin:6px 0 14px;text-wrap:balance}
.hero p{color:var(--muted);font-size:1.08rem;margin:0}
.sect-h{font-size:.74rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);font-weight:600;margin:28px 0 12px}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:14px}
.card{display:flex;flex-direction:column;gap:6px;padding:18px;border:1px solid var(--line);border-radius:14px;background:var(--surface);text-decoration:none;color:var(--ink);min-width:0}
.card:hover{border-color:var(--accent)}
.card:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.card b{font-family:var(--f-display);font-size:1.15rem;letter-spacing:-.01em}
.card span{color:var(--muted);font-size:.92rem}
.card em{font-style:normal;font-family:var(--f-num);font-size:.75rem;color:var(--accent);margin-top:auto;padding-top:6px}
/* Páginas legales */
.legal{max-width:70ch}
.legal h1{font-family:var(--f-display);font-weight:700;font-size:clamp(1.8rem,4vw,2.4rem);letter-spacing:-.025em;margin:6px 0 16px}
.legal h2{font-family:var(--f-display);font-size:1.2rem;margin:28px 0 8px}
.legal p,.legal li{font-size:.98rem}
.legal table{border-collapse:collapse;width:100%;font-size:.9rem}
.legal td,.legal th{border-bottom:1px solid var(--line);padding:8px 6px;text-align:left;vertical-align:top}
.tablewrap{overflow-x:auto}
.fill{background:#fff3b0;color:#3b2f00;padding:0 4px;border-radius:4px}
.related{margin-top:36px}
footer nav a{color:var(--ink);text-decoration:none}
footer nav a:hover{text-decoration:underline}

/* Guías */
.article{max-width:70ch}
.article h1{font-family:var(--f-display);font-weight:700;font-size:clamp(1.9rem,4.4vw,2.7rem);letter-spacing:-.025em;line-height:1.1;margin:6px 0 14px;text-wrap:balance}
.article .lede{margin-bottom:22px}
.article h2{font-family:var(--f-display);font-size:1.3rem;letter-spacing:-.01em;margin:32px 0 8px;text-wrap:balance}
.article p,.article li{font-size:1.02rem;line-height:1.65}
.article ul{padding-left:20px;display:flex;flex-direction:column;gap:6px}
.article table{border-collapse:collapse;width:100%;font-size:.92rem;font-variant-numeric:tabular-nums}
.article th{font-size:.78rem;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);font-weight:600}
.article td,.article th{border-bottom:1px solid var(--line);padding:9px 8px;text-align:left;vertical-align:top}
.article .tablewrap{margin-block:12px}
.meta{font-size:.85rem;color:var(--muted);margin:0 0 6px}
.cta{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px 20px;padding:18px 20px;border-radius:14px;background:var(--accent-soft);margin-block:28px}
.cta p{margin:0;font-weight:500}
.cta a{background:var(--accent);color:var(--accent-ink);text-decoration:none;font-weight:600;padding:10px 16px;border-radius:10px;white-space:nowrap}
.cta a:focus-visible{outline:2px solid var(--ink);outline-offset:2px}
.related ul{list-style:none;padding:0;display:flex;flex-direction:column;gap:8px}
.related a{font-weight:600}
.sources{margin-top:32px;padding-top:16px;border-top:1px solid var(--line)}
.sources h2{font-size:1rem;margin:0 0 8px}
.sources ul{list-style:none;padding:0;display:flex;flex-direction:column;gap:6px;font-size:.92rem}