dialog {
    position: absolute;
    left: 0;
    right: 0;
    width: -moz-fit-content;
    width: -webkit-fit-content;
    width: fit-content;
    height: -moz-fit-content;
    height: -webkit-fit-content;
    height: fit-content;
    margin: auto;
    border: solid;
    padding: 0;
    background: #fff;
    color: #000;
    display: block
}

dialog:not([open]) {
    display: none
}

dialog+.backdrop {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    background: rgba(0, 0, 0, .1)
}

._dialog_overlay {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0
}

dialog.fixed {
    position: fixed;
    top: 50%;
    transform: translate(0, -50%)
}