<!DOCTYPE html>
<html lang="ja">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>.arrow-explain2 {
  position: relative; /* 追加 */
  width: 60px;
  height: 20px;
  margin-right: 30px; /* 追加 */
  color: #0000cc;
  background: currentColor;
  top: 30px; /* 追加 */
}
.arrow-explain2:after {
  content: "";
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  left: 100%;
  width: 0;
  height: 0;
  border: 30px solid currentColor;
  border-top-color: transparent;
  border-right-color: transparent;
  border-right-width: 0;
  border-bottom-color: transparent;
}</style>
</head>
<body>
<html lang="en">
<body>
<div class="arrow-explain2">
</div>
<script>
</script>
</body>
</html>
.arrow-explain2 {
  position: relative; /* 追加 */
  width: 60px;
  height: 20px;
  margin-right: 30px; /* 追加 */
  color: #0000cc;
  background: currentColor;
  top: 30px; /* 追加 */
}
.arrow-explain2:after {
  content: "";
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  left: 100%;
  width: 0;
  height: 0;
  border: 30px solid currentColor;
  border-top-color: transparent;
  border-right-color: transparent;
  border-right-width: 0;
  border-bottom-color: transparent;
}