:root {
  --marca: #0f766e;
  --fondo: #f8fafc;
  --texto: #0f172a;
  --suave: #475569;
}

* { box-sizing: border-box; margin: 0; }

body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--fondo);
  color: var(--texto);
  line-height: 1.6;
}

.aviso {
  background: #fef3c7;
  text-align: center;
  font-size: 0.85rem;
  padding: 0.4rem 1rem;
}

.encabezado, main, footer {
  max-width: 64rem;
  margin: 0 auto;
  padding: 1.25rem 1rem;
}

.encabezado { display: flex; justify-content: space-between; align-items: center; }
.logo { font-weight: 800; font-size: 1.4rem; color: var(--marca); }
nav a { margin-left: 1rem; color: var(--texto); text-decoration: none; }

.hero { padding: 3rem 0; }
.hero h1 { font-size: clamp(2rem, 5vw, 3rem); line-height: 1.15; }
.hero p { color: var(--suave); margin: 1rem 0 1.5rem; max-width: 36rem; }

.boton {
  display: inline-block;
  background: var(--marca);
  color: #fff;
  padding: 0.75rem 1.25rem;
  border-radius: 0.6rem;
  text-decoration: none;
  font-weight: 600;
}

section { padding: 2rem 0; }
h2 { margin-bottom: 1rem; }

.tarjetas { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr)); }
.tarjetas article { background: #fff; border: 1px solid #e2e8f0; border-radius: 1rem; padding: 1.25rem; }

footer { color: var(--suave); font-size: 0.85rem; }