/* =========================================================
   Inversión Serena — hoja de estilos principal
   Mobile-first, sin dependencias externas, ligera y rápida.
   ========================================================= */

:root {
  /* Paleta financiera: azules (confianza) + verdes (crecimiento) */
  --color-primary: #0e3a5f;
  --color-primary-dark: #0a2c48;
  --color-primary-light: #1f6fa5;
  --color-secondary: #1f8a70;
  --color-secondary-light: #2ea883;
  --color-accent: #e9b949;

  --color-bg: #f7fafc;
  --color-bg-alt: #eef3f7;
  --color-surface: #ffffff;
  --color-border: #dbe4ec;

  --color-text: #1b2430;
  --color-text-muted: #55677a;
  --color-text-on-primary: #f7fafc;

  --color-warning-bg: #fff8e8;
  --color-warning-border: #e9b949;
  --color-ad-bg: #f1f3f5;
  --color-ad-border: #c9d2da;

  --radius: 10px;
  --radius-sm: 6px;
  --max-width: 1140px;
  --content-width: 760px;

  --font-base: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;

  --shadow-sm: 0 1px 3px rgba(14, 58, 95, 0.08);
  --shadow-md: 0 4px 16px rgba(14, 58, 95, 0.10);
}

/* ---------- Reset básico ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-base);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.65;
  font-size: 17px;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-primary-light); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3, h4 { color: var(--color-primary-dark); line-height: 1.25; margin-top: 1.6em; margin-bottom: 0.6em; }
h1 { font-size: 2rem; margin-top: 0; }
h2 { font-size: 1.5rem; border-bottom: 2px solid var(--color-bg-alt); padding-bottom: 0.3em; }
h3 { font-size: 1.2rem; color: var(--color-primary); }
p { margin: 0 0 1.1em; }
ul, ol { margin: 0 0 1.1em; padding-left: 1.4em; }
li { margin-bottom: 0.4em; }
strong { color: var(--color-primary-dark); }
small { color: var(--color-text-muted); }

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.1rem;
}

/* ---------- Utilidades ---------- */
.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.visually-hidden {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0; padding: 0; margin: -1px;
}
.skip-link {
  position: absolute; left: -999px; top: 0; background: var(--color-primary);
  color: #fff; padding: 0.6em 1em; z-index: 200; border-radius: 0 0 var(--radius-sm) 0;
}
.skip-link:focus { left: 0; }

/* ---------- Barra superior de aviso ---------- */
.top-notice {
  background: var(--color-primary-dark);
  color: #cfe0ee;
  font-size: 0.82rem;
  text-align: center;
  padding: 0.45em 1em;
}
.top-notice a { color: #fff; text-decoration: underline; }

/* ---------- Header ---------- */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 1.1rem;
  max-width: var(--max-width);
  margin: 0 auto;
}
.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--color-primary-dark);
}
.logo:hover { text-decoration: none; }
.logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px; height: 34px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
  color: #fff;
  font-size: 1.05rem;
}
.logo-text-muted { color: var(--color-secondary); }

.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px; height: 42px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  cursor: pointer;
}
.nav-toggle span, .nav-toggle::before, .nav-toggle::after {
  content: "";
  display: block;
  width: 20px; height: 2px;
  background: var(--color-primary-dark);
  position: relative;
}
.nav-toggle::before { transform: translateY(-6px); position: absolute; }
.nav-toggle::after { transform: translateY(6px); position: absolute; }

.main-nav {
  display: none;
  flex-direction: column;
  gap: 0;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
}
.main-nav.is-open { display: flex; }
.main-nav a {
  display: block;
  padding: 0.9rem 1.1rem;
  color: var(--color-text);
  border-bottom: 1px solid var(--color-bg-alt);
  font-weight: 600;
}
.main-nav a:hover, .main-nav a[aria-current="page"] { color: var(--color-primary); text-decoration: none; background: var(--color-bg-alt); }

@media (min-width: 860px) {
  .nav-toggle { display: none; }
  .main-nav {
    display: flex;
    flex-direction: row;
    background: none;
    border-top: none;
    gap: 0.2rem;
  }
  .main-nav a {
    border-bottom: none;
    padding: 0.6rem 0.9rem;
    border-radius: var(--radius-sm);
  }
}

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(160deg, var(--color-primary-dark) 0%, var(--color-primary) 55%, var(--color-secondary) 130%);
  color: var(--color-text-on-primary);
  padding: 3rem 0 2.5rem;
}
.hero h1 { color: #fff; font-size: 2.1rem; max-width: 700px; }
.hero p { color: #d8e6f0; font-size: 1.1rem; max-width: 620px; }
.hero-actions { display: flex; gap: 0.8rem; flex-wrap: wrap; margin-top: 1.3rem; }

.btn {
  display: inline-block;
  padding: 0.75em 1.4em;
  border-radius: var(--radius-sm);
  font-weight: 700;
  cursor: pointer;
  border: 2px solid transparent;
}
.btn-primary { background: var(--color-accent); color: var(--color-primary-dark); }
.btn-primary:hover { background: #f3c866; text-decoration: none; }
.btn-outline { border-color: rgba(255,255,255,0.55); color: #fff; }
.btn-outline:hover { background: rgba(255,255,255,0.12); text-decoration: none; }

/* ---------- Layout de contenido con sidebar ---------- */
.page-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  padding: 2.2rem 0 3rem;
}
@media (min-width: 900px) {
  .page-layout.with-sidebar {
    grid-template-columns: minmax(0, var(--content-width)) minmax(260px, 320px);
    align-items: start;
  }
}

.content { min-width: 0; }
.sidebar { min-width: 0; display: flex; flex-direction: column; gap: 1.5rem; }

/* ---------- Tarjetas ---------- */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.3rem;
  box-shadow: var(--shadow-sm);
}
.card h3 { margin-top: 0; }

.grid-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.3rem;
  margin: 1.5rem 0;
}
@media (min-width: 640px) {
  .grid-cards { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 980px) {
  .grid-cards.cols-3 { grid-template-columns: repeat(3, 1fr); }
}

.article-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.article-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); }
.article-card .card-tag {
  display: inline-block;
  align-self: flex-start;
  background: var(--color-bg-alt);
  color: var(--color-secondary);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  padding: 0.25em 0.7em;
  border-radius: 999px;
  margin: 1rem 1rem 0;
}
.article-card .card-body { padding: 0.7rem 1.1rem 1.2rem; flex: 1; display: flex; flex-direction: column; }
.article-card h3 { margin-top: 0.3rem; font-size: 1.1rem; }
.article-card p { color: var(--color-text-muted); font-size: 0.95rem; flex: 1; }
.article-card .read-more { font-weight: 700; font-size: 0.92rem; }

.category-pill-row { display: flex; flex-wrap: wrap; gap: 0.6rem; margin: 1.2rem 0; }
.category-pill {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  color: var(--color-primary-dark);
  padding: 0.5em 1em;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.9rem;
}
.category-pill:hover { background: var(--color-secondary-light); color: #fff; text-decoration: none; }

/* ---------- Bloques de anuncios AdSense ---------- */
.ad-slot {
  background: var(--color-ad-bg);
  border: 1px dashed var(--color-ad-border);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  font-size: 0.8rem;
  text-align: center;
  margin: 1.8rem auto;
  padding: 1rem;
  min-height: 90px;
}
.ad-slot::before {
  content: "Publicidad";
  display: block;
  width: 100%;
}
.ad-slot-header { max-width: 728px; min-height: 90px; margin: 0.8rem auto; }
.ad-slot-incontent { max-width: 100%; min-height: 250px; }
.ad-slot-sidebar { min-height: 250px; position: sticky; top: 90px; }
.ad-slot-footer { max-width: 728px; min-height: 90px; }

/* ---------- Artículo ---------- */
.article-header { padding: 2.2rem 0 0.5rem; }
.breadcrumbs { font-size: 0.85rem; color: var(--color-text-muted); margin-bottom: 0.8rem; }
.breadcrumbs a { color: var(--color-text-muted); }
.article-meta {
  display: flex; flex-wrap: wrap; gap: 0.5rem 1rem;
  color: var(--color-text-muted); font-size: 0.88rem; margin-bottom: 1.2rem;
}
.article-tag {
  display: inline-block; background: var(--color-bg-alt); color: var(--color-secondary);
  font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.03em;
  padding: 0.25em 0.7em; border-radius: 999px; margin-bottom: 0.8rem;
}
.lead {
  font-size: 1.12rem;
  color: var(--color-text-muted);
}

.disclaimer-box {
  background: var(--color-warning-bg);
  border-left: 4px solid var(--color-warning-border);
  border-radius: var(--radius-sm);
  padding: 1rem 1.2rem;
  margin: 1.5rem 0;
  font-size: 0.95rem;
}
.disclaimer-box strong { color: var(--color-primary-dark); }

.key-takeaways {
  background: var(--color-bg-alt);
  border-radius: var(--radius);
  padding: 1.2rem 1.4rem;
  margin: 1.6rem 0;
}
.key-takeaways h2 { margin-top: 0; border-bottom: none; font-size: 1.15rem; }

/* Tablas */
.table-wrap { overflow-x: auto; margin: 1.4rem 0; }
table {
  border-collapse: collapse;
  width: 100%;
  min-width: 420px;
  background: var(--color-surface);
  font-size: 0.95rem;
}
caption { text-align: left; font-size: 0.85rem; color: var(--color-text-muted); margin-bottom: 0.5em; }
th, td {
  border: 1px solid var(--color-border);
  padding: 0.6em 0.8em;
  text-align: left;
}
thead th { background: var(--color-bg-alt); color: var(--color-primary-dark); }
tbody tr:nth-child(even) { background: var(--color-bg); }

/* FAQ (usa <details>/<summary> nativos, sin JS) */
.faq-section { margin-top: 2rem; }
.faq-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  margin-bottom: 0.7rem;
  overflow: hidden;
}
.faq-item summary {
  cursor: pointer;
  padding: 0.9em 1.1em;
  font-weight: 700;
  color: var(--color-primary-dark);
  list-style: none;
  position: relative;
  padding-right: 2.2em;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 1em; top: 0.75em;
  font-size: 1.2em;
  color: var(--color-secondary);
}
.faq-item[open] summary::after { content: "–"; }
.faq-item .faq-answer { padding: 0 1.1em 1.1em; color: var(--color-text-muted); }

/* Enlaces relacionados */
.related-articles {
  margin-top: 2.2rem;
  padding-top: 1.6rem;
  border-top: 1px solid var(--color-border);
}
.related-list { display: grid; grid-template-columns: 1fr; gap: 0.8rem; padding: 0; list-style: none; margin: 0; }
@media (min-width: 640px) { .related-list { grid-template-columns: 1fr 1fr; } }
.related-list a {
  display: block;
  background: var(--color-bg-alt);
  border-radius: var(--radius-sm);
  padding: 0.9em 1em;
  font-weight: 600;
  color: var(--color-primary-dark);
}
.related-list a:hover { background: var(--color-secondary-light); color: #fff; text-decoration: none; }

/* Autor / caja de credibilidad */
.author-box {
  display: flex; gap: 1rem; align-items: flex-start;
  background: var(--color-bg-alt);
  border-radius: var(--radius);
  padding: 1.2rem;
  margin-top: 2rem;
}
.author-avatar {
  flex-shrink: 0;
  width: 52px; height: 52px; border-radius: 50%;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  color: #fff; display: flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: 1.1rem;
}

/* Índice de contenidos */
.toc {
  background: var(--color-bg-alt);
  border-radius: var(--radius);
  padding: 1.1rem 1.3rem;
  margin: 1.5rem 0;
}
.toc h2 { margin-top: 0; font-size: 1.05rem; border-bottom: none; }
.toc ol { margin: 0; padding-left: 1.3em; }
.toc a { font-weight: 600; }

/* ---------- Secciones home ---------- */
.section { padding: 2.6rem 0; }
.section-alt { background: var(--color-bg-alt); }
.section-title { text-align: left; margin-bottom: 0.3rem; }
.section-subtitle { color: var(--color-text-muted); margin-bottom: 1.6rem; max-width: 640px; }

.pillar-callout {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.6rem;
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  box-shadow: var(--shadow-sm);
}
@media (min-width: 760px) {
  .pillar-callout { flex-direction: row; align-items: center; justify-content: space-between; }
}

/* ---------- Formulario de contacto ---------- */
.form-field { margin-bottom: 1.1rem; display: flex; flex-direction: column; gap: 0.4rem; }
.form-field label { font-weight: 700; font-size: 0.92rem; }
.form-field input, .form-field textarea {
  padding: 0.7em 0.9em;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 1rem;
  background: var(--color-surface);
}
.form-field input:focus, .form-field textarea:focus {
  outline: 2px solid var(--color-primary-light);
  outline-offset: 1px;
}
.form-note { font-size: 0.85rem; color: var(--color-text-muted); }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--color-primary-dark);
  color: #c7d7e4;
  padding: 2.6rem 0 1.4rem;
  margin-top: 2rem;
  font-size: 0.92rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.8rem;
  margin-bottom: 1.8rem;
}
@media (min-width: 700px) {
  .footer-grid { grid-template-columns: 1.3fr 1fr 1fr; }
}
.footer-grid h4 { color: #fff; margin: 0 0 0.8rem; font-size: 1rem; }
.footer-grid ul { list-style: none; padding: 0; margin: 0; }
.footer-grid li { margin-bottom: 0.5em; }
.footer-grid a { color: #c7d7e4; }
.footer-grid a:hover { color: #fff; }
.footer-brand { display: flex; align-items: center; gap: 0.5rem; font-weight: 800; color: #fff; font-size: 1.15rem; margin-bottom: 0.6rem; }
.footer-disclaimer {
  border-top: 1px solid rgba(255,255,255,0.12);
  padding-top: 1.2rem;
  font-size: 0.82rem;
  color: #9fb4c6;
  line-height: 1.6;
}
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.12);
  margin-top: 1.2rem;
  padding-top: 1.2rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.6rem;
  font-size: 0.82rem;
  color: #9fb4c6;
}

/* ---------- Páginas legales ---------- */
.legal-content h2 { margin-top: 1.8em; }
.legal-content ul { padding-left: 1.4em; }
.update-date { color: var(--color-text-muted); font-size: 0.9rem; margin-bottom: 1.5rem; }