padding-block-start

padding-block-start: 20px;
writing-mode: horizontal-tb;

padding-block-start: 20px;
writing-mode: vertical-rl;

padding-block-start: 5em;
writing-mode: horizontal-tb;

padding-block-start: 5em;
writing-mode: vertical-lr;

<section id="default-example">
  <div class="transition-all" id="example-element">
    <div class="box">
      Far out in the uncharted backwaters of the unfashionable end of the
      western spiral arm of the Galaxy lies a small unregarded yellow sun.
    </div>
  </div>
</section>

#example-element {
  border: 10px solid #ffc129;
  overflow: hidden;
  text-align: left;
}

.box {
  border: dashed 1px;
  unicode-bidi: bidi-override;
}

/* <length> 値 */
padding-block-start: 10px; /* 絶対的な長さ */
padding-block-start: 1em; /* テキストの大きさに対する相対値 */

/* <percentage> 値 */
padding-block-start: 5%; /* ブロックコンテナーの幅に対する割合のパディング */

/* グローバル値 */
padding-block-start: inherit;
padding-block-start: initial;
padding-block-start: revert;
padding-block-start: revert-layer;
padding-block-start: unset;

<div>
  <p class="exampleText">テキストの例</p>
</div>

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

.exampleText {
  writing-mode: vertical-lr;
  padding-block-start: 20px;
  background-color: #c8c800;
}