Where to add ccs code in enfold child theme ?

I’d like to keep my quick CSS code under the chield enfold folder instead of settings > general styling.

Which file should i edit?

example this code, where can i save it under enfold chield?

.avia-post-next .date-container.minor-meta {
    position: absolute;
    left: 20px;
}

.avia-post-prev .date-container.minor-meta {
    right: 20px;
    position: absolute;
}