media-alignment.css

.ck-content .drupal-media-style-align-right {
  float: right;
  margin-left: 1.5rem;
}
.ck-content .drupal-media-style-align-left {
  float: left;
  margin-right: 1.5rem;
}
.ck-content .drupal-media-style-align-left,
.ck-content .drupal-media-style-align-right {
  clear: both;
  max-width: 50%;
}
.ck-content .drupal-media-style-align-center {
  max-width: 50%;
  margin-right: auto;
  margin-left: auto;
}

File

core/modules/ckeditor5/css/media-alignment.css

View source 
  1. .ck-content .drupal-media-style-align-right {

  2.   float: right;

  3.   margin-left: 1.5rem;

  4. }

  5. .ck-content .drupal-media-style-align-left {

  6.   float: left;

  7.   margin-right: 1.5rem;

  8. }

  9. .ck-content .drupal-media-style-align-left,

  10. .ck-content .drupal-media-style-align-right {

  11.   clear: both;

  12.   max-width: 50%;

  13. }

  14. .ck-content .drupal-media-style-align-center {

  15.   max-width: 50%;

  16.   margin-right: auto;

  17.   margin-left: auto;

  18. }