<h1 class="cp_h1title">見出しテキスト</h1>
.cp_h1title {
position: relative;
padding: .1em .3em .1em .5em;
border-left: 6px solid #26C6DA;
}
.cp_h1title::before {
position: absolute;
content: '';
left: -6px;
bottom: 0;
width: 6px;
height: 50%;
background-color: #1A237E;
}
.cp_h1title::after {
position: absolute;
content: '';
left: 0;
bottom: 0;
width: 100%;
height: 0;
border-bottom: 1px solid #26C6DA;
}