<ol class="cp_clist">
  <li>css</li>
  <li>html</li>
  <li>copy</li>
  <li>easy</li>
</ol>

ol.cp_clist {
  padding: 0;
  counter-reset:cp_clist; /*数字をリセット*/
  list-style-type: none;
}
ol.cp_clist li {
  position: relative;
  padding: 0 0 0 40px;
  margin: 0 0 20px -40px;
  color: #333;
}
ol.cp_clist li::before {
  position: absolute;
  top: 0;
  left: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  /* カウントさせる */
  counter-increment: cp_clist;
  content: counter(cp_clist);
  /*装飾*/
  background: #F8BBD0;
  height: 20px;
  width: 20px;
  font: italic bold 1em/1em Georgia, Serif;
  border: .1em solid rgba(0,0,0,.05);
  border-radius: 20px;
  /*位置の調整*/
  padding: 0;
  transition: all .2s ease-out;
}
/*hover時の設定*/
ol.cp_clist li:hover::before {
  background-color: #F06292;
  border-color: rgba(0,0,0,.08);
  border-width: 4px;
  color: #fff;
  transform: scale(1.5);
  transform-origin: bottom;
}