list-style-image

list-style-image: url("/shared-assets/images/examples/rocket.svg");

list-style-image: none;

<section class="default-example" id="default-example">
  <div>
    <p>NASA Notable Missions</p>
    <ul class="transition-all unhighlighted" id="example-element">
      <li>Apollo</li>
      <li>Hubble</li>
      <li>Chandra</li>
      <li>Cassini-Huygens</li>
      <li>Spitzer</li>
    </ul>
  </div>
</section>

.default-example {
  font-size: 1.2rem;
}
#example-element {
  width: 100%;
  background: #be094b;
  color: white;
}
section {
  text-align: left;
  flex-direction: column;
}
hr {
  width: 50%;
  color: lightgray;
  margin: 0.5em;
}
.note {
  font-size: 0.8rem;
}
.note a {
  color: #009e5f;
}
@counter-style space-counter {
  symbols: "\1F680" "\1F6F8" "\1F6F0" "\1F52D";
  suffix: " ";
}

/* キーワード値 */
list-style-image: none;
/* <url>  値 */
list-style-image: url("star-solid.gif");
/* 有効な画像値 */
list-style-image: linear-gradient(to left bottom, red, blue);
/* グローバル値 */
list-style-image: inherit;
list-style-image: initial;
list-style-image: revert;
list-style-image: revert-layer;
list-style-image: unset;

<ul>
  <li>アイテム 1</li>
  <li>アイテム 2</li>
</ul>

ul {
  list-style-image: url("star-solid.gif");
}

<ul>
  <li>アイテム 1</li>
  <li>アイテム 2</li>
</ul>

ul {
  font-size: 200%;
  list-style-image: linear-gradient(to left bottom, red, blue);
}