<h1 class="cp_h1title">見出しテキスト</h1>
.cp_h1title {
position: relative;
padding: 0.1em 0.3em;
border-left: 10px solid #FFA000;
}
.cp_h1title::after {
position: absolute;
left: 0;
bottom: 0;
content: '';
width: 100%;
height: 0;
border-bottom: 3px solid #B0BEC5;
}