Separator

<div style="
    /* Content is centered horizontally */
    align-items: center;
    display: flex;

    /* Used to set the position of text */
    position: relative;
">
    <!-- Text -->
    <div style="
        /* We won't see the separator line */
        background: #FFF;

        /* Displayed at the center of container */
        left: 50%;
        position: absolute;
        top: 50%;
        transform: translate(-50%, -50%);
    ">
        ...
    </div>

    <!-- Separator line -->
    <div style="
        border-bottom: 1px solid rgba(0, 0, 0, 0.3);
        height: 1px;
        width: 100%;
    " />
</div>