anki/ts/editor/editable.scss

anki-editable {
    display: block;
    overflow-wrap: break-word;
    overflow: auto;
    padding: 6px;

    &:empty::after {
        content: "\a";
        white-space: pre;
    }
}

img {
    max-width: 100%;

    &.drawing {
        zoom: 50%;

        .nightMode & {
            filter: unquote("invert() hue-rotate(180deg)");
        }
    }
}