:root {
  --fondo: #f7f7f5; --superficie: #ffffff; --tinta: #1c1d21; --tinta-2: #55575f; --borde: #e3e3df;
  --acento: #3b5bdb; --acento-suave: #e8edff;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --fondo: #121316; --superficie: #1b1c20; --tinta: #ececef; --tinta-2: #a4a6ae; --borde: #2c2d33;
    --acento: #8ea6ff; --acento-suave: #1f2540;
  }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--fondo); color: var(--tinta);
  font: 16px/1.65 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
a { color: var(--acento); }
header, main, footer { max-width: 760px; margin: 0 auto; padding: 0 16px; }
header { display: flex; justify-content: space-between; align-items: center; padding-top: 24px; padding-bottom: 24px; }
header .marca { font-weight: 700; font-size: 1.15rem; text-decoration: none; color: var(--tinta); letter-spacing: -0.01em; }
header nav a { margin-left: 16px; color: var(--tinta-2); text-decoration: none; font-size: .95rem; }
h1 { font-size: clamp(1.8rem, 5vw, 2.6rem); line-height: 1.15; letter-spacing: -0.02em; margin: 24px 0 12px; }
h2 { font-size: 1.25rem; margin: 36px 0 8px; }
h3 { font-size: 1.05rem; margin: 24px 0 4px; }
p, li { color: var(--tinta-2); }
.lead { font-size: 1.15rem; }
.tarjeta { background: var(--superficie); border: 1px solid var(--borde); border-radius: 12px; padding: 20px; margin: 16px 0; }
.boton { display: inline-block; background: var(--acento); color: #fff; padding: 12px 20px; border-radius: 10px;
  text-decoration: none; font-weight: 600; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .boton { color: #121316; } }
.rejilla { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 12px; }
.rejilla .tarjeta { margin: 0; }
.rejilla h3 { margin-top: 0; }
.nota { font-size: .9rem; }
footer { padding-top: 48px; padding-bottom: 32px; font-size: .9rem; color: var(--tinta-2); }
footer a { color: var(--tinta-2); margin-right: 16px; }