Hi!
Thanks for your answer. I managed to translate ‘Continue reading’ by changing these lines in functions.php:
function libre_continue_reading_link() {
return '… <a class="more-link" href="'. esc_url( get_permalink() ) . '">' . sprintf( wp_kses_post( __( 'Seguir leyendo <span class="screen-reader-text">%1$s</span> <span class="meta-nav" aria-hidden="true">→</span>', 'libre' ) ), esc_attr( strip_tags( get_the_title() ) ) ) . '</a>';
}
However, I think your solution is better.
By the way, I’ve completed the Spanish translation on Glotpress (some strings were missing, for example, ‘next post‘ or ‘previous post‘).
Thanks again.