It looks like your media query is missing the closest bracket } (at the very end of your CSS).
1. Try this CSS:
.wp-show-posts-entry-title {
line-height: 1em;
}2. You need to duplicate the selectors where you have an ID:
#wpsp-2687 p.wp-show-posts-entry-title,
#wpsp-1234 p.wp-show-posts-entry-title {
....
}