margin-block-end CSS property

margin-block-end: 20px;
writing-mode: horizontal-tb;

margin-block-end: 20px;
writing-mode: vertical-rl;

margin-block-end: 20%;
writing-mode: horizontal-tb;

margin-block-end: auto;
writing-mode: vertical-lr;

<section id="default-example">
  <div id="container">
    <div class="row">One</div>
    <div class="row transition-all" id="example-element">Two</div>
    <div class="row">Three</div>
  </div>
</section>

#container {
  width: 300px;
  height: 200px;
  display: flex;
  align-content: flex-start;
  flex-direction: column;
  justify-content: flex-start;
}

.row {
  height: 33.33%;
  display: inline-block;
  border: solid #ce7777 10px;
  background-color: #2b3a55;
  color: white;
  flex-shrink: 0;
}

#example-element {
  border: solid 10px #ffbf00;
  background-color: #2b3a55;
}

/* <length> values */
margin-block-end: 10px; /* An absolute length */
margin-block-end: 1em; /* relative to the text size */
margin-block-end: 5%; /* relative to the nearest block container's width */
margin-block-end: anchor-size(inline);
margin-block-end: calc(anchor-size(--my-anchor block, 20px) / 4);

/* Keyword values */
margin-block-end: auto;

/* Global values */
margin-block-end: inherit;
margin-block-end: initial;
margin-block-end: revert;
margin-block-end: revert-layer;
margin-block-end: unset;

<div>
  <p class="exampleText">Example text</p>
</div>

div {
  background-color: yellow;
  width: 120px;
  height: 120px;
}

.exampleText {
  writing-mode: vertical-rl;
  margin-block-end: 20px;
  background-color: #c8c800;
}