postdown/static/markdown.css

pre {
  background-color: #f5f5f5;
  padding: 0.5rem 0.25rem;
  border-radius: 0.25rem;
}
table {
  border-collapse: collapse;
}
table th, table td {
  border: 1px solid #d6d6d6;
  padding: 0.25rem 0.5rem;
}