/* Fotograma Latente — tema editorial. Light por defecto, dark por sistema/toggle. */
:root{
  --bg:#ffffff; --bg-soft:#f6f7f9; --bg-card:#ffffff; --fg:#15171c; --fg-soft:#4a4f59;
  --muted:#6b7280; --line:#e5e7eb; --line-soft:#eef0f3;
  --accent:#5b3df5; --accent-2:#0bb3c4; --accent-ink:#ffffff;
  --grad:linear-gradient(100deg,#5b3df5,#a63cf0 45%,#0bb3c4);
  --maxw:1120px; --narrow:720px; --radius:14px; --shadow:0 1px 2px rgba(16,18,24,.06),0 8px 24px rgba(16,18,24,.06);
  --sans:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --serif:"Iowan Old Style","Palatino Linotype",Palatino,Georgia,"Times New Roman",serif;
}
:root[data-theme="dark"]{ --bg:#0e1014; --bg-soft:#14171d; --bg-card:#161a21; --fg:#eceef2; --fg-soft:#b9bfca; --muted:#8b93a1; --line:#252b34; --line-soft:#1c222a; --accent:#8b7bff; --accent-2:#28c7d8; --shadow:0 1px 2px rgba(0,0,0,.4),0 10px 30px rgba(0,0,0,.35); }
@media (prefers-color-scheme:dark){ :root:not([data-theme="light"]){ --bg:#0e1014; --bg-soft:#14171d; --bg-card:#161a21; --fg:#eceef2; --fg-soft:#b9bfca; --muted:#8b93a1; --line:#252b34; --line-soft:#1c222a; --accent:#8b7bff; --accent-2:#28c7d8; --shadow:0 1px 2px rgba(0,0,0,.4),0 10px 30px rgba(0,0,0,.35);} }

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--fg);font-family:var(--sans);font-size:18px;line-height:1.65;-webkit-font-smoothing:antialiased}
.wrap{max-width:var(--maxw);margin-inline:auto;padding-inline:20px}
.narrow{max-width:var(--narrow)}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;height:auto}
h1,h2,h3,h4{line-height:1.2;letter-spacing:-.02em;font-weight:750}
.skip{position:absolute;left:-999px}
.skip:focus{left:12px;top:12px;background:var(--fg);color:var(--bg);padding:8px 12px;border-radius:8px;z-index:100}

/* Brand mark: latent frame */
.brand-mark{width:20px;height:20px;border-radius:6px;background:var(--grad);display:inline-block;box-shadow:inset 0 0 0 3px var(--bg)}
.brand-mark.lg{width:40px;height:40px;border-radius:10px;flex:0 0 auto}

/* Header */
.site-header{position:sticky;top:0;z-index:50;background:color-mix(in srgb,var(--bg) 86%,transparent);backdrop-filter:saturate(1.2) blur(10px);border-bottom:1px solid var(--line)}
.header-inner{display:flex;align-items:center;gap:20px;height:62px}
.brand{display:flex;align-items:center;gap:10px;color:var(--fg);font-weight:800;letter-spacing:-.02em}
.brand:hover{text-decoration:none}
.nav{margin-left:auto}
.menu{display:flex;gap:6px;list-style:none;margin:0;padding:0}
.menu a{display:block;padding:8px 12px;border-radius:8px;color:var(--fg-soft);font-weight:600;font-size:15px}
.menu a:hover{background:var(--bg-soft);text-decoration:none;color:var(--fg)}
.menu a[aria-current]{color:var(--accent)}
.theme-toggle{background:none;border:1px solid var(--line);color:var(--fg-soft);width:38px;height:38px;border-radius:9px;cursor:pointer;font-size:16px}
.nav-toggle{display:none;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer;padding:8px}
.nav-toggle span{width:22px;height:2px;background:var(--fg)}

/* Hero */
.hero{padding:64px 0 40px;background:radial-gradient(1200px 400px at 15% -10%,color-mix(in srgb,var(--accent) 14%,transparent),transparent),var(--bg)}
.hero-kicker{font-weight:700;text-transform:uppercase;letter-spacing:.12em;font-size:12.5px;color:var(--accent)}
.hero-title{font-size:clamp(2rem,5.4vw,3.4rem);margin:.2em 0 .3em;max-width:16ch}
.grad{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero-lede{font-size:1.2rem;color:var(--fg-soft);max-width:56ch}
.hero-cta{display:flex;gap:12px;flex-wrap:wrap;margin-top:22px}
.btn{display:inline-block;background:var(--accent);color:var(--accent-ink);padding:12px 20px;border-radius:11px;font-weight:700;border:1px solid transparent}
.btn:hover{text-decoration:none;filter:brightness(1.06)}
.btn.ghost{background:transparent;color:var(--fg);border-color:var(--line)}

/* Feature card */
.feature{display:block;margin:36px 0;padding:28px;border:1px solid var(--line);border-radius:var(--radius);background:var(--bg-card);box-shadow:var(--shadow);color:var(--fg)}
.feature:hover{text-decoration:none;border-color:color-mix(in srgb,var(--accent) 40%,var(--line))}
.feature h2{margin:.15em 0 .3em;font-size:1.7rem}
.feature p{color:var(--fg-soft);margin:0 0 .5em}
.feature-go{color:var(--accent);font-weight:700}
.kicker{display:inline-block;font-size:12.5px;font-weight:700;text-transform:uppercase;letter-spacing:.1em;color:var(--accent)}

/* Cards grid */
.row-title{font-size:1.4rem;margin:36px 0 16px}
.card-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:18px;margin-bottom:48px}
.card{border:1px solid var(--line);border-radius:var(--radius);background:var(--bg-card);overflow:hidden;transition:transform .12s ease,border-color .12s ease}
.card:hover{transform:translateY(-2px);border-color:color-mix(in srgb,var(--accent) 35%,var(--line))}
.card a{display:block;padding:20px;color:var(--fg)}
.card a:hover{text-decoration:none}
.card-tag{font-size:11.5px;text-transform:uppercase;letter-spacing:.09em;font-weight:700;color:var(--muted)}
.card h3{margin:.35em 0 .35em;font-size:1.18rem}
.card p{margin:0;color:var(--fg-soft);font-size:.95rem}

/* Breadcrumbs */
.breadcrumbs{padding:20px 0 6px}
.breadcrumbs ol{display:flex;flex-wrap:wrap;gap:8px;list-style:none;margin:0;padding:0;font-size:13.5px;color:var(--muted)}
.breadcrumbs li+li::before{content:"/";margin-right:8px;color:var(--line)}
.breadcrumbs a{color:var(--muted)}

/* Article */
.article-head{padding:6px 0 10px;border-bottom:1px solid var(--line-soft);margin-bottom:26px}
.article-head h1{font-size:clamp(1.9rem,4.4vw,2.7rem);margin:.15em 0 .25em}
.lede{font-size:1.22rem;color:var(--fg-soft)}
.article-meta{display:flex;flex-wrap:wrap;gap:14px;color:var(--muted);font-size:14px;margin-top:14px}
.article-meta .upd{color:var(--accent-2);font-weight:600}
.toc{background:var(--bg-soft);border:1px solid var(--line);border-radius:12px;padding:16px 20px;margin:0 0 28px;font-size:15px}
.toc strong{display:block;margin-bottom:6px;font-size:13px;text-transform:uppercase;letter-spacing:.08em;color:var(--muted)}
.toc ul{margin:0;padding-left:18px}
.toc a{color:var(--fg-soft)}

/* Prose */
.prose{font-size:1.06rem}
.prose>h2{font-size:1.62rem;margin:1.9em 0 .5em;padding-top:.3em}
.prose>h3{font-size:1.28rem;margin:1.5em 0 .4em}
.prose p{margin:0 0 1.1em}
.prose ul,.prose ol{margin:0 0 1.2em;padding-left:1.3em}
.prose li{margin:.35em 0}
.prose a{text-decoration:underline;text-underline-offset:2px}
.prose blockquote{margin:1.4em 0;padding:.4em 1.1em;border-left:3px solid var(--accent);color:var(--fg-soft);background:var(--bg-soft);border-radius:0 10px 10px 0}
.prose img{border-radius:12px;border:1px solid var(--line)}
.prose figure{margin:1.6em 0}
.prose figcaption{color:var(--muted);font-size:14px;text-align:center;margin-top:8px}
.prose code{background:var(--bg-soft);border:1px solid var(--line);border-radius:6px;padding:.1em .4em;font-size:.9em}
.prose pre{background:#0d1117;color:#e6edf3;padding:18px;border-radius:12px;overflow:auto}
.prose pre code{background:none;border:0;padding:0}
.prose table{width:100%;border-collapse:collapse;margin:1.4em 0;font-size:.96rem;display:block;overflow-x:auto}
.prose th,.prose td{border:1px solid var(--line);padding:10px 12px;text-align:left;vertical-align:top}
.prose thead th{background:var(--bg-soft);font-weight:700}
.prose tbody tr:nth-child(even){background:color-mix(in srgb,var(--bg-soft) 55%,transparent)}

/* GEO datos + nota */
.datos{background:linear-gradient(180deg,color-mix(in srgb,var(--accent) 9%,var(--bg-soft)),var(--bg-soft));border:1px solid color-mix(in srgb,var(--accent) 22%,var(--line));border-radius:12px;padding:16px 20px;margin:1.6em 0}
.datos-title{display:block;font-size:12.5px;text-transform:uppercase;letter-spacing:.09em;color:var(--accent);margin-bottom:6px}
.datos-body>*:first-child{margin-top:0}.datos-body>*:last-child{margin-bottom:0}
.nota{border:1px solid var(--line);border-left:3px solid var(--accent-2);background:var(--bg-soft);border-radius:0 10px 10px 0;padding:12px 16px;margin:1.4em 0;font-size:.98rem}
.nota--aviso{border-left-color:#e0a800}
.nota p:last-child{margin-bottom:0}

/* FAQ */
.faq{margin:44px 0 10px;border-top:1px solid var(--line);padding-top:26px}
.faq h2{font-size:1.5rem;margin:0 0 14px}
.faq-item{border:1px solid var(--line);border-radius:11px;margin-bottom:10px;background:var(--bg-card);overflow:hidden}
.faq-item summary{cursor:pointer;padding:15px 18px;font-weight:650;list-style:none;display:flex;justify-content:space-between;gap:12px}
.faq-item summary::-webkit-details-marker{display:none}
.faq-item summary::after{content:"+";color:var(--accent);font-weight:700}
.faq-item[open] summary::after{content:"–"}
.faq-answer{padding:0 18px 16px;color:var(--fg-soft)}
.faq-answer>*:first-child{margin-top:0}

/* Tabla de herramientas (interactiva) */
.th-wrap{margin:1.6em 0}
.th-filter{width:100%;max-width:340px;padding:10px 14px;border:1px solid var(--line);border-radius:10px;background:var(--bg);color:var(--fg);font-size:1rem;font-family:inherit;margin-bottom:14px}
.th-scroll{overflow-x:auto;border:1px solid var(--line);border-radius:12px}
.th-table{width:100%;border-collapse:collapse;font-size:.94rem}
.th-table th,.th-table td{padding:11px 14px;text-align:left;border-bottom:1px solid var(--line-soft);white-space:nowrap}
.th-table thead th{background:var(--bg-soft);font-weight:700;position:sticky;top:0}
.th-sortable{cursor:pointer;user-select:none}
.th-sortable:hover{color:var(--accent)}
.th-sortable::after{content:"↕";opacity:.4;margin-left:5px;font-size:11px}
.th-asc::after{content:"↑";opacity:1;color:var(--accent)}
.th-desc::after{content:"↓";opacity:1;color:var(--accent)}
.th-table tbody tr:hover{background:var(--bg-soft)}
.th-table a{font-weight:600}
.th-bar{display:inline-block;width:64px;height:9px;border-radius:5px;background:var(--line);position:relative;vertical-align:middle}
.th-bar::before{content:"";position:absolute;left:0;top:0;bottom:0;width:calc(var(--n)/5*100%);background:var(--grad);border-radius:5px}
.th-precio{font-size:.82rem;font-weight:600;padding:2px 9px;border-radius:20px;border:1px solid var(--line)}
.th-p-bajo{color:#0a8f57;border-color:color-mix(in srgb,#0a8f57 40%,var(--line))}
.th-p-medio{color:#b8860b;border-color:color-mix(in srgb,#b8860b 40%,var(--line))}
.th-p-alto{color:#c0492b;border-color:color-mix(in srgb,#c0492b 40%,var(--line))}
.th-nota{font-size:12.5px;color:var(--muted);margin-top:10px}

/* Búsqueda */
.search-trigger{background:none;border:1px solid var(--line);color:var(--fg-soft);width:38px;height:38px;border-radius:9px;cursor:pointer;display:inline-flex;align-items:center;justify-content:center}
.search-trigger:hover{color:var(--fg);border-color:color-mix(in srgb,var(--accent) 40%,var(--line))}
.search-overlay{position:fixed;inset:0;z-index:200;background:color-mix(in srgb,#0e1014 55%,transparent);backdrop-filter:blur(3px);display:none;align-items:flex-start;justify-content:center;padding:12vh 20px 20px}
.search-overlay.open{display:flex}
.search-box{width:100%;max-width:600px;background:var(--bg-card);border:1px solid var(--line);border-radius:16px;box-shadow:var(--shadow);overflow:hidden}
.search-input{width:100%;border:0;border-bottom:1px solid var(--line);background:transparent;color:var(--fg);font-size:1.15rem;padding:18px 20px;font-family:inherit;outline:none}
.search-results{max-height:52vh;overflow-y:auto}
.search-hit{display:block;padding:12px 20px;border-bottom:1px solid var(--line-soft);color:var(--fg)}
.search-hit:hover{background:var(--bg-soft);text-decoration:none}
.search-hit-tag{display:block;font-size:11px;text-transform:uppercase;letter-spacing:.08em;color:var(--muted)}
.search-hit strong{display:block;font-size:1rem;margin:2px 0}
.search-hit-d{display:block;font-size:.88rem;color:var(--fg-soft)}
.search-empty{padding:20px;color:var(--muted)}
.search-hint{padding:10px 20px;font-size:12.5px;color:var(--muted);background:var(--bg-soft)}
.search-hint kbd{background:var(--bg);border:1px solid var(--line);border-radius:4px;padding:1px 5px;font-size:11px}

/* Barra de progreso de lectura */
.reading-progress{position:fixed;top:0;left:0;right:0;height:3px;z-index:60;background:transparent;pointer-events:none}
.reading-progress span{display:block;height:100%;width:0;background:var(--grad);transition:width .1s linear}

/* Gráficos (Chart.js) */
.grafico{margin:1.8em 0;padding:18px;border:1px solid var(--line);border-radius:14px;background:var(--bg-card)}
.grafico-tit{font-weight:700;font-size:1rem;margin-bottom:12px;color:var(--fg)}
.grafico-canvas{position:relative;height:340px;width:100%}
.grafico-tabla{margin-top:12px;font-size:.9rem}
.grafico-tabla summary{cursor:pointer;color:var(--accent);font-weight:600}
.grafico-tabla table{width:100%;margin-top:10px;border-collapse:collapse}
.grafico-tabla th,.grafico-tabla td{border:1px solid var(--line);padding:6px 10px;text-align:left}
.grafico-fuente{font-size:12.5px;color:var(--muted);margin:10px 0 0}
.comparativa-vis,.ilustracion{margin:1.6em 0}
.comparativa-vis svg,.ilustracion svg{width:100%;height:auto;border-radius:16px;display:block}

/* Relacionados */
.relacionados{margin:44px 0 10px;border-top:1px solid var(--line);padding-top:26px}
.relacionados h2{font-size:1.4rem;margin:0 0 16px}
.rel-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:14px}
.rel-card{display:block;padding:16px;border:1px solid var(--line);border-radius:12px;background:var(--bg-card);color:var(--fg)}
.rel-card:hover{text-decoration:none;border-color:color-mix(in srgb,var(--accent) 35%,var(--line));transform:translateY(-2px);transition:.12s}
.rel-card span{display:block;font-size:11.5px;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);margin-bottom:6px}
.rel-card strong{font-size:1rem;line-height:1.3}

/* Author box */
.author-box{display:flex;gap:16px;align-items:flex-start;margin:40px 0 10px;padding:20px;border:1px solid var(--line);border-radius:14px;background:var(--bg-soft)}
.author-box strong{display:block}
.author-box p{margin:.35em 0 .5em;color:var(--fg-soft);font-size:.96rem}

/* Section head */
.section-head{padding:8px 0 22px}
.section-head h1{font-size:clamp(1.8rem,4vw,2.5rem)}
.section-intro{color:var(--fg-soft);max-width:70ch}

/* Calculadora */
.calc{border:1px solid var(--line);border-radius:14px;background:var(--bg-card);padding:22px;margin:1.6em 0;box-shadow:var(--shadow)}
.calc .field{margin-bottom:14px}
.calc label{display:block;font-weight:600;margin-bottom:6px;font-size:.95rem}
.calc input,.calc select{width:100%;padding:10px 12px;border:1px solid var(--line);border-radius:10px;background:var(--bg);color:var(--fg);font-size:1rem;font-family:inherit}
.calc .row{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.calc-out{margin-top:16px;padding:16px;border-radius:12px;background:var(--bg-soft);border:1px solid var(--line)}
.calc-out .big{font-size:2rem;font-weight:800;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.calc small{color:var(--muted)}

/* Footer */
.site-footer{margin-top:64px;border-top:1px solid var(--line);background:var(--bg-soft)}
.footer-inner{display:flex;flex-wrap:wrap;gap:32px;justify-content:space-between;padding:40px 0 20px}
.footer-brand{max-width:340px}
.footer-brand p{color:var(--muted);font-size:.92rem;margin:.5em 0 0}
.footer-nav{display:flex;flex-wrap:wrap;gap:8px 20px;align-content:flex-start}
.footer-nav a{color:var(--fg-soft);font-size:.95rem}
.footer-legal{border-top:1px solid var(--line);padding:16px 0 30px}
.footer-legal p{color:var(--muted);font-size:13px;margin:0}

@media (max-width:720px){
  body{font-size:17px}
  .menu{position:absolute;top:62px;left:0;right:0;flex-direction:column;background:var(--bg);border-bottom:1px solid var(--line);padding:8px 16px 16px;display:none}
  .menu.open{display:flex}
  .nav-toggle{display:flex}
  .calc .row{grid-template-columns:1fr}
  .author-box{flex-direction:column}
}