/* MaterialsMath — hoja de estilo unica.
   Sin webfonts ni peticiones externas: cero requests de terceros y CWV en verde.
   Los huecos de anuncio llevan altura reservada para no provocar CLS. */

:root {
  --bg: #ffffff;
  --bg-soft: #f4f6f8;
  --bg-card: #ffffff;
  --ink: #14202b;
  --ink-soft: #4d5c69;
  --line: #dde3e9;
  --accent: #0b5c8a;
  --accent-ink: #ffffff;
  --amber: #b46b00;
  --amber-soft: #fff6e6;
  --radius: 10px;
  --wrap: 1180px;
  --measure: 74ch;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #10171e;
    --bg-soft: #172029;
    --bg-card: #1a232d;
    --ink: #e8eef4;
    --ink-soft: #a3b1bd;
    --line: #2b3742;
    --accent: #57b6e8;
    --accent-ink: #0a1219;
    --amber: #e8a447;
    --amber-soft: #2a2113;
  }
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.65;
  color: var(--ink);
  background: var(--bg);
}

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 20px; }

a { color: var(--accent); }
a:hover { text-decoration-thickness: 2px; }

h1, h2, h3 { line-height: 1.25; font-weight: 700; }
h1 { font-size: clamp(1.75rem, 1.2rem + 2vw, 2.4rem); margin: 0 0 .4em; letter-spacing: -.015em; }
h2 { font-size: clamp(1.3rem, 1.1rem + .8vw, 1.6rem); margin: 2em 0 .5em; }
h3 { font-size: 1.15rem; margin: 1.6em 0 .4em; }

.skip {
  position: absolute; left: -9999px; top: 0; z-index: 100;
  background: var(--accent); color: var(--accent-ink); padding: .6em 1em;
}
.skip:focus { left: 0; }

:focus-visible { outline: 3px solid var(--amber); outline-offset: 2px; }

/* ---------- cabecera ---------- */

.site-header { border-bottom: 1px solid var(--line); background: var(--bg); }
.header-inner { display: flex; align-items: center; gap: 1rem; min-height: 60px; flex-wrap: wrap; }

.logo {
  font-weight: 700; font-size: 1.15rem; text-decoration: none; color: var(--ink);
  display: inline-flex; align-items: center; gap: .45rem; margin-right: auto;
}
.logo-mark {
  display: inline-grid; place-items: center; width: 1.6em; height: 1.6em;
  background: var(--accent); color: var(--accent-ink); border-radius: 6px; font-size: .85em;
}

.nav-toggle {
  display: none; background: none; border: 1px solid var(--line); border-radius: 6px;
  color: var(--ink); font-size: 1.2rem; padding: .2em .5em; cursor: pointer;
}

.site-nav ul { display: flex; gap: 1.1rem; list-style: none; margin: 0; padding: 0; flex-wrap: wrap; }
.site-nav a { color: var(--ink-soft); text-decoration: none; font-size: .93rem; font-weight: 500; }
.site-nav a:hover { color: var(--accent); text-decoration: underline; }

@media (max-width: 820px) {
  .nav-toggle { display: block; }
  .site-nav { flex-basis: 100%; display: none; }
  .site-nav.open { display: block; }
  .site-nav ul { flex-direction: column; gap: 0; padding-bottom: .6rem; }
  .site-nav li { border-top: 1px solid var(--line); }
  .site-nav a { display: block; padding: .6rem 0; }
}

/* ---------- layout de dos columnas ---------- */

.layout { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 2.5rem; align-items: start; }
.col-main { min-width: 0; padding-bottom: 3rem; }
.col-main--solo { max-width: var(--measure); }
.col-side { position: sticky; top: 1rem; }

@media (max-width: 980px) {
  .layout { grid-template-columns: 1fr; gap: 1.5rem; }
  .col-side { position: static; }
}

.breadcrumb { font-size: .85rem; color: var(--ink-soft); margin: 1.2rem 0 1rem; }
.breadcrumb a { color: var(--ink-soft); }

.lede { font-size: 1.13rem; color: var(--ink-soft); max-width: var(--measure); margin: 0 0 1.5rem; }

/* ---------- calculadora ---------- */

.calc {
  background: var(--bg-soft); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.4rem; margin: 0 0 1.5rem;
}
.calc-title { margin: 0 0 1rem; font-size: 1.15rem; }

.calc-form fieldset { border: 0; margin: 0 0 1rem; padding: 0; }
.calc-form legend {
  font-weight: 600; font-size: .8rem; text-transform: uppercase; letter-spacing: .06em;
  color: var(--ink-soft); padding: 0; margin-bottom: .6rem;
}

.fields { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); gap: 1rem; }

.field label { display: block; font-weight: 600; font-size: .92rem; margin-bottom: .3rem; }
.field .unit { font-weight: 400; color: var(--ink-soft); }
.field input[type="text"], .field input[type="number"], .field select {
  width: 100%; padding: .55em .7em; font: inherit; font-size: 1rem;
  color: var(--ink); background: var(--bg-card);
  border: 1px solid var(--line); border-radius: 7px;
}
.field input:focus, .field select:focus { border-color: var(--accent); }
.field--checkbox { display: flex; align-items: center; gap: .5rem; }
.field--checkbox label { margin: 0; }
.field--checkbox input { width: 1.15em; height: 1.15em; }
.help { font-size: .82rem; color: var(--ink-soft); margin: .3rem 0 0; }

.results { border-top: 2px solid var(--line); margin-top: 1.2rem; padding-top: 1.1rem; }
.results-title { margin: 0 0 .7rem; font-size: .8rem; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-soft); }
.result-list { list-style: none; margin: 0; padding: 0; display: grid; gap: .5rem; }
.result {
  display: flex; align-items: baseline; gap: .5rem; flex-wrap: wrap;
  padding: .55em .8em; background: var(--bg-card); border: 1px solid var(--line); border-radius: 7px;
}
.result-label { flex: 1 1 auto; min-width: 45%; }
.result-value { font-weight: 700; font-size: 1.25rem; font-variant-numeric: tabular-nums; }
.result-unit { color: var(--ink-soft); font-size: .9rem; }
.result-note { flex-basis: 100%; font-size: .82rem; color: var(--ink-soft); }
.result--primary { background: var(--amber-soft); border-color: var(--amber); }
.result--primary .result-value { color: var(--amber); font-size: 1.6rem; }

.calc-error { color: #b3261e; font-size: .9rem; margin: .8rem 0 0; }
@media (prefers-color-scheme: dark) { .calc-error { color: #ff8a80; } }

/* ---------- siguiente paso ---------- */

.next-steps {
  border: 1px solid var(--line); border-left: 4px solid var(--accent);
  border-radius: var(--radius); padding: 1rem 1.2rem; margin: 2rem 0;
}
.next-steps h2 { margin: 0 0 .6rem; font-size: 1.05rem; }
.next-list { list-style: none; margin: 0; padding: 0; display: grid; gap: .55rem; }
.next-list a { font-weight: 600; }
.next-why { display: block; font-size: .87rem; color: var(--ink-soft); }

/* ---------- prosa ---------- */

.prose { max-width: var(--measure); }
.prose p, .prose ul, .prose ol { margin: 0 0 1.1em; }
.prose li { margin-bottom: .35em; }
.prose strong { font-weight: 700; }
.prose code { font-family: var(--mono); font-size: .9em; background: var(--bg-soft); padding: .1em .35em; border-radius: 4px; }

/* Los bloques de formula desbordaban la ventana en movil: tienen que hacer
   scroll dentro de su propia caja, nunca ensanchar la pagina. */
.prose pre {
  overflow-x: auto;
  max-width: 100%;
  margin: 0 0 1.3em;
  padding: .9em 1.1em;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.prose pre code { background: none; padding: 0; font-size: .86em; line-height: 1.55; }
.prose blockquote {
  margin: 1.4em 0; padding: .1em 1.1em; border-left: 4px solid var(--amber);
  color: var(--ink-soft); background: var(--amber-soft); border-radius: 0 var(--radius) var(--radius) 0;
}

/* ---------- tablas ---------- */

.table-scroll { overflow-x: auto; margin: 0 0 1.3em; }
table { border-collapse: collapse; width: 100%; font-size: .95rem; }
th, td { text-align: left; padding: .55em .8em; border-bottom: 1px solid var(--line); }
thead th { background: var(--bg-soft); font-size: .82rem; text-transform: uppercase; letter-spacing: .04em; white-space: nowrap; }
tbody th { font-weight: 600; }
td { font-variant-numeric: tabular-nums; }

/* ---------- FAQ, supuestos, fuentes ---------- */

.faq details {
  border: 1px solid var(--line); border-radius: 7px; padding: .7em 1em; margin-bottom: .6rem;
}
.faq summary { font-weight: 600; cursor: pointer; }
.faq details > div { padding-top: .5em; color: var(--ink-soft); }
.faq details > div p:last-child { margin-bottom: 0; }

.assumptions, .sources { max-width: var(--measure); font-size: .95rem; color: var(--ink-soft); }
.sources li { margin-bottom: .4em; }

.updated { font-size: .85rem; color: var(--ink-soft); margin-top: 2.5rem; }

/* ---------- tarjetas ---------- */

.hero { background: var(--bg-soft); border-bottom: 1px solid var(--line); padding: 2.5rem 0 2rem; margin-bottom: 2rem; }
.hero h1 { margin-bottom: .3em; }
.hero .lede { font-size: 1.2rem; }

.silo-block { margin: 0 0 3rem; }
.silo-block h2 { margin-top: 0; }
.silo-block h2 a { text-decoration: none; color: var(--ink); }
.silo-block h2 a:hover { color: var(--accent); }
.silo-lede { color: var(--ink-soft); max-width: var(--measure); margin-top: -.3em; }

.card-grid { list-style: none; margin: 1.2rem 0 0; padding: 0; display: grid; gap: .9rem; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); }
.card a {
  display: block; height: 100%; padding: .9rem 1rem; text-decoration: none;
  background: var(--bg-card); border: 1px solid var(--line); border-radius: var(--radius);
}
.card a:hover { border-color: var(--accent); }
.card-title { display: block; font-weight: 650; color: var(--ink); margin-bottom: .2rem; }
.card-desc { display: block; font-size: .87rem; color: var(--ink-soft); line-height: 1.45; }
.more { font-weight: 600; }

.related { margin-bottom: 1.8rem; }
.related h2 { font-size: .8rem; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-soft); margin: 0 0 .6rem; }
.related ul { list-style: none; margin: 0; padding: 0; }
.related li { border-top: 1px solid var(--line); }
.related a { display: block; padding: .45em 0; font-size: .93rem; text-decoration: none; }
.related a:hover { text-decoration: underline; }

/* ---------- huecos de anuncio ----------
   Altura reservada desde el primer pintado: los anuncios no deben mover nada. */

.ad-slot { margin: 2rem 0; min-height: 100px; display: block; }
.ad-slot--after-calc { min-height: 280px; }
.ad-slot--in-content { min-height: 280px; }
.ad-slot--rail { min-height: 600px; margin-top: 0; }
@media (max-width: 980px) { .ad-slot--rail { min-height: 280px; } }

/* ---------- aviso de consentimiento ----------
   Fijo abajo y por encima del contenido: no empuja nada, asi que no hay CLS.
   Aceptar y rechazar tienen el mismo peso visual a proposito. */

.consent {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 60;
  background: var(--bg-card);
  border-top: 1px solid var(--line);
  box-shadow: 0 -6px 24px rgba(0, 0, 0, .12);
  padding: 1rem 20px calc(1rem + env(safe-area-inset-bottom, 0px));
}
.consent-inner {
  max-width: var(--wrap); margin: 0 auto;
  display: flex; align-items: center; gap: 1.5rem; flex-wrap: wrap;
}
.consent-text { flex: 1 1 380px; min-width: 0; }
.consent-text p { margin: 0; font-size: .92rem; line-height: 1.55; color: var(--ink-soft); }
.consent-text p:first-child { color: var(--ink); margin-bottom: .2rem; }
.consent-actions { display: flex; gap: .6rem; flex: 0 0 auto; }

.btn {
  font: inherit; font-size: .93rem; font-weight: 600;
  padding: .6em 1.4em; border-radius: 7px; cursor: pointer;
  border: 1px solid var(--accent); background: var(--accent); color: var(--accent-ink);
}
.btn:hover { filter: brightness(1.08); }
.btn--ghost { background: transparent; color: var(--accent); }
.btn--ghost:hover { background: var(--bg-soft); filter: none; }

@media (max-width: 560px) {
  .consent-inner { gap: .9rem; }
  .consent-actions { width: 100%; }
  .consent-actions .btn { flex: 1 1 0; }
}

/* ---------- pie ---------- */

.site-footer { border-top: 1px solid var(--line); background: var(--bg-soft); padding: 2rem 0; margin-top: 2rem; }
.disclaimer { font-size: .87rem; color: var(--ink-soft); max-width: 80ch; }
.footer-links { list-style: none; display: flex; flex-wrap: wrap; gap: 1.1rem; padding: 0; margin: 1rem 0; font-size: .9rem; }
.copyright { font-size: .82rem; color: var(--ink-soft); margin: 0; }