:root {
  --bg: #fbfaf7;
  --surface: #ffffff;
  --text: #1d2321;
  --muted: #5b6662;
  --line: #e4e1da;
  --accent: #1f7a5a;
  --accent-soft: #e5f2ec;
  --warn: #b5651d;
  --radius: 10px;
  --max: 1120px;
  --read: 720px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121615;
    --surface: #1a1f1e;
    --text: #e8ecea;
    --muted: #a3ada9;
    --line: #2c3331;
    --accent: #4cc497;
    --accent-soft: #1d2f28;
    --warn: #e0a165;
  }
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Source Sans 3", system-ui, -apple-system, "Segoe UI", sans-serif;
  font-size: 18px;
  line-height: 1.65;
}

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

img { max-width: 100%; height: auto; }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 16px; }
.read { max-width: var(--read); margin: 0 auto; padding: 0 16px; }

/* Cabecera */
.site-header {
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  padding-top: 14px;
  padding-bottom: 14px;
}
.logo {
  font-family: "Fraunces", Georgia, serif;
  font-weight: 700;
  font-size: 1.35rem;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.01em;
}
.logo span { color: var(--accent); }
.site-nav { display: flex; gap: 20px; flex-wrap: wrap; font-size: 0.95rem; }
.site-nav a { color: var(--muted); text-decoration: none; }
.site-nav a:hover, .site-nav a[aria-current="page"] { color: var(--text); }

/* Portada */
.hero { padding: 56px 0 40px; }
.hero h1 {
  font-family: "Fraunces", Georgia, serif;
  font-size: clamp(2rem, 5vw, 3.1rem);
  line-height: 1.12;
  margin: 0 0 16px;
  max-width: 18ch;
  letter-spacing: -0.02em;
}
.hero p { color: var(--muted); max-width: 56ch; margin: 0; font-size: 1.1rem; }

.section-title {
  font-family: "Fraunces", Georgia, serif;
  font-size: 1.5rem;
  margin: 40px 0 16px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}
.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.card .tag {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  font-weight: 600;
}
.card h3 { margin: 0; font-size: 1.2rem; line-height: 1.3; }
.card h3 a { color: var(--text); text-decoration: none; }
.card h3 a:hover { color: var(--accent); }
.card p { margin: 0; color: var(--muted); font-size: 0.98rem; }
.card .meta { font-size: 0.85rem; color: var(--muted); margin-top: auto; }

.topics { display: flex; flex-wrap: wrap; gap: 10px; margin: 0; padding: 0; list-style: none; }
.topics li {
  background: var(--accent-soft);
  color: var(--text);
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 0.92rem;
}

/* Artículo */
.article { padding: 40px 0 24px; }
.article .breadcrumb { font-size: 0.9rem; color: var(--muted); margin-bottom: 12px; }
.article .breadcrumb a { color: var(--muted); }
.article h1 {
  font-family: "Fraunces", Georgia, serif;
  font-size: clamp(1.9rem, 4.5vw, 2.6rem);
  line-height: 1.15;
  margin: 0 0 12px;
  letter-spacing: -0.015em;
}
.article .lead { font-size: 1.15rem; color: var(--muted); margin: 0 0 8px; }
.article .byline { font-size: 0.9rem; color: var(--muted); margin-bottom: 28px; }
.article h2 { font-family: "Fraunces", Georgia, serif; font-size: 1.5rem; margin: 36px 0 10px; line-height: 1.25; }
.article h3 { font-size: 1.15rem; margin: 26px 0 6px; }
.article ul, .article ol { padding-left: 1.3em; }
.article li { margin-bottom: 6px; }

.toc {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin: 24px 0;
  font-size: 0.98rem;
}
.toc strong { display: block; margin-bottom: 6px; }
.toc ol { margin: 0; }

.callout {
  border-left: 4px solid var(--accent);
  background: var(--accent-soft);
  padding: 14px 18px;
  border-radius: 0 var(--radius) var(--radius) 0;
  margin: 24px 0;
}
.callout.warn { border-color: var(--warn); }

.table-wrap { overflow-x: auto; margin: 20px 0; }
table { border-collapse: collapse; width: 100%; font-size: 0.96rem; }
th, td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--line); }
th { background: var(--surface); }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }

.disclaimer {
  font-size: 0.88rem;
  color: var(--muted);
  border-top: 1px solid var(--line);
  padding-top: 16px;
  margin-top: 40px;
}

.related { margin: 32px 0; }
.related ul { padding-left: 1.2em; }

/* Calculadora */
.calc {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  margin: 24px 0;
}
.calc .fields { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 14px; }
.calc label { display: flex; flex-direction: column; font-size: 0.92rem; color: var(--muted); gap: 4px; }
.calc input {
  font: inherit;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px 10px;
}
.calc .out { margin-top: 16px; display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 12px; }
.calc .out div { background: var(--accent-soft); border-radius: 8px; padding: 12px; }
.calc .out span { display: block; font-size: 0.82rem; color: var(--muted); }
.calc .out b { font-size: 1.3rem; font-variant-numeric: tabular-nums; }

/* Formularios */
form.contact { display: grid; gap: 14px; margin: 24px 0; }
form.contact label { display: grid; gap: 4px; font-size: 0.95rem; }
form.contact input, form.contact textarea {
  font: inherit; color: var(--text); background: var(--surface);
  border: 1px solid var(--line); border-radius: 8px; padding: 10px 12px;
}
.btn {
  font: inherit; font-weight: 600; background: var(--accent); color: #fff;
  border: 0; border-radius: 8px; padding: 10px 18px; cursor: pointer; justify-self: start;
}

/* Espacios publicitarios de AdSense */
.ad-slot {
  margin: 32px auto;
  min-height: 100px;
  text-align: center;
  overflow: hidden;
}
.ad-slot::before {
  content: "Publicidad";
  display: block;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 4px;
}

/* Pie */
.site-footer {
  margin-top: 64px;
  border-top: 1px solid var(--line);
  background: var(--surface);
  font-size: 0.92rem;
  color: var(--muted);
}
.site-footer .wrap {
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 16px;
  padding-top: 24px; padding-bottom: 24px;
}
.site-footer nav { display: flex; gap: 16px; flex-wrap: wrap; }
.site-footer a { color: var(--muted); }

@media (max-width: 600px) {
  body { font-size: 17px; }
  .hero { padding: 36px 0 24px; }
}

/* Imágenes, autor y portada por categorías */
.hero-img { margin: 0 0 24px; border-radius: var(--radius); overflow: hidden; border: 1px solid var(--line); }
.hero-img img { display: block; width: 100%; height: auto; }
.hero-grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 32px; align-items: center; }
.hero-grid p { margin-bottom: 20px; }
.hero-art { width: 100%; height: auto; border-radius: var(--radius); border: 1px solid var(--line); }
.btn { display: inline-block; text-decoration: none; }
a.btn:hover { color: #fff; filter: brightness(1.08); }
.topics a { color: inherit; text-decoration: none; }
.topics li:hover { filter: brightness(0.96); }
.card-img { display: block; margin: -22px -22px 6px; border-radius: var(--radius) var(--radius) 0 0; overflow: hidden; }
.card-img img { display: block; width: 100%; height: auto; aspect-ratio: 2 / 1; object-fit: cover; }
.cat-section { scroll-margin-top: 16px; }
.cat-head p { color: var(--muted); margin: -8px 0 16px; }
.author-box { display: flex; gap: 16px; align-items: flex-start; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 20px; margin: 32px 0; }
.author-box p { margin: 4px 0 0; font-size: 0.95rem; color: var(--muted); }
.author-avatar { flex: none; width: 52px; height: 52px; border-radius: 50%; background: var(--accent); color: #fff; display: grid; place-items: center; font-weight: 700; font-family: "Fraunces", Georgia, serif; }
@media (max-width: 760px) { .hero-grid { grid-template-columns: 1fr; } .hero-art { display: none; } }