数字と線を組み合わせた見出し – 数字と下線

HTML

<h2 class="heading" data-number="01">採用情報について</h2>

CSS

.heading {
  position: relative;
  padding-left: 2em;
  font-size: 26px;
}

.heading::before {
  content: attr(data-number);
  position: absolute;
  top: 0;
  left: 0;
  padding-bottom: 5px;
  color: #e5c046;
  font-size: 26px;
  font-weight: 800;
  border-bottom: 1px solid #e5c046;
}