:host {
    vertical-align: top;
}

.outer {
    margin: 0.25em;
    border: 2px solid gray;
    display: inline-block;
    width: 40ch;
    height: 5em;
}

/*noinspection CssUnresolvedCustomProperty*/
.inner {
    background-color: var(--backColor, #ffffff);
    color: var(--textColor, #000000);
    padding: 0.1em
}