:root { --max: 60rem; --borde: #ccc; --fondo-suave: #f6f6f6; }
* { box-sizing: border-box; }
body { font-family: system-ui, sans-serif; line-height: 1.5; margin: 0 auto; max-width: var(--max); padding: 0 1rem 3rem; }
header, section, footer { margin-top: 2.5rem; }
h1 { font-size: 1.6rem; }
h2 { border-bottom: 2px solid #222; padding-bottom: .25rem; }
a { color: #0645ad; }
header p a { display: inline-block; background: #222; color: #fff; padding: .5rem 1rem; margin-right: .5rem; text-decoration: none; border-radius: .25rem; }
iframe { border: 1px solid var(--borde); margin-top: 1rem; }
table { border-collapse: collapse; width: 100%; margin: 1rem 0; font-size: .9rem; }
caption { font-weight: bold; text-align: left; margin-bottom: .25rem; }
th, td { border: 1px solid var(--borde); padding: .35rem .5rem; text-align: left; }
thead th { background: var(--fondo-suave); }
tbody tr:nth-child(even) { background: var(--fondo-suave); }
div button, div input { margin: .25rem .25rem .25rem 0; padding: .4rem .7rem; font-size: 1rem; }
pre { background: #1e1e1e; color: #e6e6e6; padding: 1rem; overflow-x: auto; font-size: .8rem; }
ol { padding-left: 1.25rem; }
footer { border-top: 1px solid var(--borde); color: #555; font-size: .85rem; }
@media (max-width: 40rem) {
  h1 { font-size: 1.25rem; }
  table { display: block; overflow-x: auto; }
  iframe { height: 400px; }
}