pelican-elegant/static/css/custom.css

figure img {
  display: block;
  margin-left: auto;
  margin-right: auto;
}

/* Next 2 rules add ability to have paragraph numbers */
.article-content p {
  padding-left: 50px;
  position: relative;
}

.article-content p:before {
  display: block;
  position: absolute;
  left: 5px;
}