editor.css

body {
	margin: 0 auto;
	padding: 2rem;
  font-family: -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;
	font-size: inherit;
	max-width: 50rem;
}

body.wp-autoresize {
  padding: 2rem !important;
}

a, a:visited {
  color: rgb(40, 52, 175);
  text-decoration: none;
}
a:hover {
  cursor: pointer;
  text-decoration: underline;
}

table {
  width: 100%;
}

thead {
  color: black;
  font-size: 1.125rem;
  font-weight: bold;
}

.btn,
.mce-content-body a[data-mce-selected].btn {
  background-color: rgb(40, 52, 175);
  color: #fff !important;
  font-size: 1rem;
  font-weight: bold;
  padding: 0.425em 1.25em;
  display: inline-block;
  text-decoration: none;
  cursor: pointer;
  margin-left: 0;
  margin-right: 0.5em;
}

.wpview.wpview-wrap {
  width: 100%;
  height: 0;
  position: relative;
  padding-bottom: 56.25%;
}

.wpview.wpview-wrap iframe {
  position: absolute;
  width: 100%;
  height: 100%;
}