取消二重線

<div>
    テキストを入力<span class="delete">この部分に二重線を引く</span>
</div>

.delete {
    position: relative;
}
.delete:after {
    position: absolute;
    left: 0;
    top: 50%;

    display: block;
    content: "";
    width: 100%;
    height: 2px;

    margin-top: -2px;
    border-top: 1px solid red;
    border-bottom: 1px solid red;
    
}