dd_popup {
    box-sizing: border-box;
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0,0,0,.5);
    display: none;
    justify-content: center;
    padding: 0 .5em;
    z-index: var(--z-popup, 999999);
    overflow: auto;
}

dd_popup > * {
    box-sizing: border-box;
    max-width: 100%;
    width: 400px;
    padding: .9em 1em;
    border-radius: .5em;
    background: #eee;
    position: relative;
    margin: auto 0;
}

dd_popup_x_close {
    box-sizing: border-box;
    display: block;
    position: absolute;
    top: .3em;
    right: .3em;
    font-weight: bold;
    color: #000;
    font-family: sans-serif;
    font-size: 1.5rem;
    line-height: 1.5rem;
    opacity: .4;
    border-radius: .5rem;
    cursor: pointer;
}

dd_popup_x_close::before {
    box-sizing: border-box;
    content: "\00D7";
}

dd_popup_x_close:hover {
    background: rgba(0,0,0,.1);
    opacity: 1;
}