/* ¿Qué termo compro?
   Concepto: ficha técnica de instalador. Azul petróleo (agua) + cobre (calor). La capacidad en litros es el dato
   protagonista: va en un marcador circular, como la etiqueta de un depósito. Botón de oferta en cobre con texto blanco. */
:root {
  --bg: #f2f5f7;
  --surface: #ffffff;
  --ink: #102433;
  --muted: #536472;
  --line: #d7dfe5;
  --soft: #e8eef2;
  --deep: #0e3147;
  --on-deep: #ffffff;
  --accent: #0f6b8f;
  --heat: #c2541f;
  --heat-hover: #a54415;
  --on-heat: #ffffff;
  --good: #23784f;
  --bad: #b23b2e;
  --cold: #3b8fc7;

  --f-display: "Red Hat Display", "Segoe UI", Helvetica, Arial, sans-serif;
  --f-body: "Red Hat Text", "Segoe UI", Helvetica, Arial, sans-serif;
  --f-data: "DM Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --radius: 10px;
  --wrap: 1180px;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0d1820; --surface: #13222d; --ink: #e5edf2; --muted: #9fb0bc; --line: #253845; --soft: #1a2c38;
    --deep: #0a2433; --on-deep: #ffffff; --accent: #5cb8db; --heat: #db6a32; --heat-hover: #ec7b42; --on-heat: #ffffff;
    --good: #6cc99a; --bad: #f08c80; --cold: #6fb4e3; color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0d1820; --surface: #13222d; --ink: #e5edf2; --muted: #9fb0bc; --line: #253845; --soft: #1a2c38;
  --deep: #0a2433; --on-deep: #ffffff; --accent: #5cb8db; --heat: #db6a32; --heat-hover: #ec7b42; --on-heat: #ffffff;
  --good: #6cc99a; --bad: #f08c80; --cold: #6fb4e3; color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } * { transition: none !important; } }
body { margin: 0; background: var(--bg); color: var(--ink); font: 400 1.08rem/1.65 var(--f-body); -webkit-font-smoothing: antialiased; }
img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-underline-offset: 2px; }
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible { outline: 3px solid var(--heat); outline-offset: 2px; }
.wrap { max-width: var(--wrap); margin-inline: auto; padding-left: max(16px, env(safe-area-inset-left, 0px)); padding-right: max(16px, env(safe-area-inset-right, 0px)); }

h1, h2, h3 { font-family: var(--f-display); line-height: 1.1; letter-spacing: -0.015em; text-wrap: balance; margin: 0; }
h1 { font-size: clamp(2.1rem, 5vw, 3.4rem); font-weight: 900; }
h2 { font-size: clamp(1.5rem, 3vw, 2.05rem); font-weight: 800; }
h3 { font-size: 1.18rem; font-weight: 750; }
.eyebrow { font: 500 0.78rem/1 var(--f-data); letter-spacing: 0.08em; text-transform: uppercase; color: var(--heat); }
.muted { color: var(--muted); }

/* Cabecera */
.site-header { background: var(--deep); color: var(--on-deep); }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; gap: 0.5rem 1.4rem; min-height: 62px; flex-wrap: wrap; padding-block: 0.4rem; }
.logo { display: flex; align-items: center; gap: 0.55rem; color: var(--on-deep); text-decoration: none; font: 900 1.22rem/1 var(--f-display); letter-spacing: -0.02em; }
.logo b { color: #f0a274; font-weight: 900; }
.logo svg { width: 28px; height: 28px; flex: none; }
.nav { display: flex; gap: 0.15rem 1.15rem; flex-wrap: wrap; font: 600 0.94rem/1.2 var(--f-body); }
.nav a { color: var(--on-deep); text-decoration: none; padding-block: 0.4rem; opacity: 0.9; }
.nav a:hover, .nav a[aria-current] { opacity: 1; text-decoration: underline; text-underline-offset: 5px; text-decoration-color: #f0a274; }
@media (max-width: 680px) { .nav { width: 100%; font-size: 0.9rem; gap: 0.1rem 0.9rem; } }

/* Cabecera de página: franja fría a caliente */
.hero { background: var(--surface); border-bottom: 1px solid var(--line); padding-block: clamp(1.8rem, 5vw, 3.2rem); position: relative; }
.hero::after { content: ""; position: absolute; left: 0; right: 0; bottom: -1px; height: 4px; background: linear-gradient(90deg, var(--cold), var(--heat)); }
.hero .wrap { display: grid; gap: 0.9rem; }
.hero .lead { font-size: 1.2rem; color: var(--muted); max-width: 64ch; margin: 0; }
.meta { font: 400 0.82rem/1.4 var(--f-data); color: var(--muted); display: flex; flex-wrap: wrap; gap: 0.3rem 1.2rem; margin: 0; }
.meta a { color: var(--muted); }
.crumbs { font: 400 0.8rem/1.4 var(--f-data); color: var(--muted); padding-block: 0.9rem 0; }
.crumbs ol { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 0.35rem; }
.crumbs li + li::before { content: "›"; margin-right: 0.35rem; }
.crumbs a { color: var(--muted); }

/* Botones */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 0.4em; font: 700 0.98rem/1.1 var(--f-body); text-decoration: none; padding: 0.85rem 1.15rem; border-radius: 8px; border: 0; cursor: pointer; transition: background .15s; text-align: center; }
.btn-cta { background: var(--heat); color: var(--on-heat); }
.btn-cta:hover { background: var(--heat-hover); }
.btn-cta small { font: 400 0.76rem/1 var(--f-data); opacity: 0.92; }
.btn-line { background: transparent; color: var(--ink); border: 1.5px solid var(--line); }
.btn-line:hover { border-color: var(--ink); }

/* Tarjetas de producto */
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); display: grid; grid-template-rows: auto 1fr; min-width: 0; overflow: hidden; }
.card .img { background: #ffffff; aspect-ratio: 4 / 3; display: grid; place-items: center; overflow: hidden; max-width: 100%; position: relative; border-bottom: 1px solid var(--line); }
.card .img img { width: 100%; height: 100%; object-fit: contain; padding: 0.6rem; }
.card .tag { position: absolute; left: 0.6rem; top: 0.6rem; background: var(--deep); color: var(--on-deep); font: 500 0.7rem/1 var(--f-data); letter-spacing: 0.04em; text-transform: uppercase; padding: 0.45rem 0.6rem; border-radius: 6px; }
.dial { position: absolute; right: 0.6rem; bottom: 0.6rem; width: 62px; height: 62px; border-radius: 50%; background: var(--surface); border: 3px solid var(--accent); display: grid; place-content: center; text-align: center; box-shadow: 0 2px 8px rgba(0,0,0,.08); }
.dial b { font: 900 1.15rem/1 var(--f-display); color: var(--ink); }
.dial span { font: 500 0.6rem/1.1 var(--f-data); color: var(--muted); text-transform: uppercase; }
.dial.gas { border-color: var(--heat); }
.card .body { padding: 1rem; display: grid; gap: 0.55rem; align-content: start; }
.card h3 { font-size: 1.08rem; }
.card h3 a { color: var(--ink); text-decoration: none; }
.card h3 a:hover { color: var(--accent); }
.card .marca { font: 500 0.74rem/1 var(--f-data); text-transform: uppercase; letter-spacing: 0.05em; color: var(--muted); }
.card p { margin: 0; font-size: 0.98rem; }
.chips { display: flex; flex-wrap: wrap; gap: 0.35rem; list-style: none; padding: 0; margin: 0; }
.chips li { font: 500 0.75rem/1 var(--f-data); background: var(--soft); color: var(--ink); padding: 0.4rem 0.5rem; border-radius: 6px; }
.chips li.hot { background: color-mix(in srgb, var(--heat) 14%, transparent); }
.card .acciones { display: grid; gap: 0.45rem; margin-top: 0.2rem; }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(245px, 1fr)); gap: 1rem; margin-block: 1.4rem; }
.picks { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; margin-block: 1.4rem; }
@media (max-width: 900px) { .picks { grid-template-columns: 1fr; } }
.card.wide { grid-template-columns: 230px 1fr; grid-template-rows: auto; margin-block: 1.6rem; }
.card.wide .img { aspect-ratio: auto; height: 100%; min-height: 220px; border-bottom: 0; border-right: 1px solid var(--line); }
@media (max-width: 600px) { .card.wide { grid-template-columns: 1fr; } .card.wide .img { aspect-ratio: 4 / 3; border-right: 0; border-bottom: 1px solid var(--line); } }

/* Comparativa sin scroll lateral */
.compare { width: 100%; border-collapse: separate; border-spacing: 0; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; font-size: 0.97rem; margin-block: 1.4rem; table-layout: fixed; }
.compare th, .compare td { text-align: left; padding: 0.7rem; border-bottom: 1px solid var(--line); vertical-align: middle; overflow-wrap: anywhere; }
.compare tr:last-child td { border-bottom: 0; }
.compare thead th { font: 500 0.72rem/1.2 var(--f-data); letter-spacing: 0.05em; text-transform: uppercase; color: var(--muted); background: var(--soft); }
.compare td.n { font-family: var(--f-display); font-weight: 800; }
.compare td.n a { color: var(--ink); text-decoration: none; }
.compare td.d { font: 500 0.88rem/1.35 var(--f-data); }
.compare td .btn { width: 100%; padding: 0.6rem; font-size: 0.88rem; }
@media (max-width: 760px) {
  .compare, .compare tbody, .compare tr, .compare td { display: block; width: 100%; }
  .compare thead { display: none; }
  .compare tr { border-bottom: 1px solid var(--line); padding-block: 0.5rem; }
  .compare td { border: 0; padding: 0.3rem 0.9rem; }
  .compare td[data-l]::before { content: attr(data-l) ": "; font: 500 0.72rem/1 var(--f-data); text-transform: uppercase; color: var(--muted); }
}

/* Artículo */
.layout { padding-block: 1.4rem 4rem; }
.prose { min-width: 0; }
.prose > * + * { margin-top: 1.05em; }
.prose > p, .prose > ul, .prose > ol, .prose > h2, .prose > h3, .prose > blockquote { max-width: 75ch; }
.prose h2 { margin-top: 2.3em; scroll-margin-top: 1rem; }
.prose h3 { margin-top: 1.6em; scroll-margin-top: 1rem; }
.prose h2 + p, .prose h3 + p { margin-top: 0.6em; }
.prose p, .prose li { margin-block: 0; }
.prose ul:not([class]), .prose ol:not([class]) { padding-left: 1.3rem; display: grid; gap: 0.4rem; }
.prose blockquote { margin: 1.4rem 0; padding: 1rem 1.2rem; background: var(--soft); border-left: 4px solid var(--accent); border-radius: 0 8px 8px 0; }
.prose table:not(.compare) { width: 100%; border-collapse: collapse; font-size: 0.97rem; table-layout: fixed; background: var(--surface); }
.prose table:not(.compare) th, .prose table:not(.compare) td { border: 1px solid var(--line); padding: 0.55rem 0.6rem; text-align: left; vertical-align: top; overflow-wrap: anywhere; }
.prose table:not(.compare) th { font: 500 0.74rem/1.25 var(--f-data); text-transform: uppercase; letter-spacing: 0.04em; color: var(--muted); background: var(--soft); }
.prose strong { font-weight: 700; }
.respuesta { background: var(--surface); border: 1px solid var(--line); border-left: 5px solid var(--heat); border-radius: 8px; padding: 1rem 1.2rem; max-width: 75ch; }
.respuesta p { margin: 0; }
.respuesta p + p { margin-top: 0.5em; }

.toc { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 0.9rem 1.2rem 1rem; margin-block: 1.6rem; font: 500 0.98rem/1.4 var(--f-body); }
.toc p { margin: 0 0 0.6rem; }
.toc ol { display: block; margin: 0; padding-left: 1.2rem; columns: 2 260px; column-gap: 2.5rem; }
.toc li { break-inside: avoid; padding-block: 0.18rem; }
.toc a { color: var(--ink); text-decoration: none; }
.toc a:hover { color: var(--accent); text-decoration: underline; }
.disclosure { font: 400 0.82rem/1.5 var(--f-data); color: var(--muted); border-left: 3px solid var(--heat); padding: 0.3rem 0 0.3rem 0.8rem; max-width: 75ch; }
.aviso-final { margin-top: 2.5rem; }

/* Selector por litros */
.litros, .prose ul.litros { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-block: 1rem; list-style: none; padding: 0; }
.litros a { display: grid; place-content: center; text-align: center; width: 84px; height: 84px; border-radius: 50%; background: var(--surface); border: 3px solid var(--accent); text-decoration: none; color: var(--ink); transition: transform .15s; }
.litros a:hover { transform: translateY(-2px); border-color: var(--heat); }
.litros b { font: 900 1.35rem/1 var(--f-display); }
.litros span { font: 500 0.66rem/1.2 var(--f-data); color: var(--muted); }

/* Calculadoras */
.calc { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.2rem; display: grid; gap: 1rem; margin-block: 1.6rem; }
.calc .campos { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); gap: 0.9rem; }
.calc label { display: grid; gap: 0.35rem; font: 600 0.92rem/1.25 var(--f-body); }
.calc input, .calc select { font: 500 1.02rem/1 var(--f-data); width: 100%; padding: 0.65rem; border: 1px solid var(--line); border-radius: 6px; background: var(--bg); color: var(--ink); }
.calc .res { display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 0.8rem; }
.calc .res div { background: var(--soft); border-radius: 8px; padding: 0.85rem; }
.calc .res .top { background: var(--deep); color: var(--on-deep); }
.calc .res .top span { color: rgba(255,255,255,.8); }
.calc .res b { display: block; font: 900 1.6rem/1.1 var(--f-display); }
.calc .res span { font: 400 0.8rem/1.35 var(--f-data); color: var(--muted); }
.calc .nota { margin: 0; font-size: 0.92rem; color: var(--muted); }

/* Portada: temas */
.section { padding-block: clamp(2rem, 5vw, 3.4rem); }
.alt { background: var(--surface); border-block: 1px solid var(--line); }
.section-head { display: grid; gap: 0.5rem; margin-bottom: 1.3rem; }
.topics { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 1.6rem 2rem; }
.topic h3 { font: 500 0.78rem/1 var(--f-data); text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); margin-bottom: 0.7rem; }
.topic ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.5rem; }
.topic a { font: 700 1.03rem/1.3 var(--f-display); color: var(--ink); text-decoration: none; }
.topic a:hover { color: var(--accent); }

/* Ficha */
.ficha { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: clamp(1.5rem, 4vw, 3rem); align-items: start; padding-block: 1.2rem 1rem; }
@media (max-width: 860px) { .ficha { grid-template-columns: 1fr; } }
.ficha .foto { background: #ffffff; border: 1px solid var(--line); border-radius: var(--radius); aspect-ratio: 1 / 1; max-width: 100%; display: grid; place-items: center; overflow: hidden; position: relative; }
.ficha .foto img { width: 100%; height: 100%; object-fit: contain; padding: 1rem; }
.ficha-info { display: grid; gap: 1rem; min-width: 0; }
.datos { width: 100%; border-collapse: collapse; font-size: 0.98rem; }
.datos th, .datos td { text-align: left; padding: 0.55rem 0; border-bottom: 1px solid var(--line); vertical-align: top; }
.datos th { font: 500 0.76rem/1.4 var(--f-data); text-transform: uppercase; letter-spacing: 0.05em; color: var(--muted); width: 42%; padding-right: 0.8rem; }
.proscons { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; max-width: 900px; }
@media (max-width: 640px) { .proscons { grid-template-columns: 1fr; } }
.proscons > div { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 1rem 1.1rem; }
.proscons h3 { font-size: 1rem; margin-bottom: 0.5rem; }
.proscons ul { margin: 0; padding-left: 1.1rem; display: grid; gap: 0.4rem; }
.pros h3 { color: var(--good); }
.cons h3 { color: var(--bad); }
.autor { display: flex; gap: 1rem; align-items: center; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 1rem 1.2rem; max-width: 75ch; margin-top: 2rem; }
.autor .av { width: 52px; height: 52px; border-radius: 50%; background: var(--deep); color: var(--on-deep); display: grid; place-items: center; font: 900 1.1rem/1 var(--f-display); flex: none; }
.autor p { margin: 0; font-size: 0.95rem; }

/* Pie */
.site-footer { background: var(--deep); color: var(--on-deep); padding-block: 2.5rem; margin-top: 2rem; }
.site-footer a { color: var(--on-deep); opacity: 0.88; }
.site-footer a:hover { opacity: 1; }
.site-footer p { margin: 0; max-width: 75ch; font-size: 0.97rem; opacity: 0.88; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 1.6rem; }
@media (max-width: 900px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px) { .footer-grid { grid-template-columns: 1fr; } }
.site-footer h3 { font: 500 0.76rem/1 var(--f-data); text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 0.8rem; opacity: 0.75; }
.site-footer ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.4rem; font: 500 0.95rem/1.3 var(--f-body); }
.site-footer ul a { text-decoration: none; }
.legal { margin-top: 2rem; padding-top: 1rem; border-top: 1px solid rgba(255, 255, 255, 0.2); display: flex; flex-wrap: wrap; gap: 0.4rem 1.3rem; font: 400 0.8rem/1.4 var(--f-data); }