メモ。
.title-border {
display: flex;
align-items: center;
}
.title-border:before,
.title-border:after {
border-top: 1px solid;
content: "";
flex-grow: 1;
}
.title-border:before {
margin-right: 1rem;
}
.title-border:after {
margin-left: 1rem;
}