Never mind, I found this! And it worked:
// Shows the captions all the time
.sqs-lightbox-meta.overlay-description-visible {
bottom: 0px !important;
}
// Hide the "dot" I'm using the Dark lightbox, so I color the dot dark, which blends in with the background.
a.sqs-lightbox-meta-trigger {
color:#111 !important;
}