hello vraagje!
here i read that the "+" css operator only applies to an element if it is an adjacent element (next to the other one)
http://stackoverflow.com/questions/1139763/what-does-the-plus-sign-css-selector-mean
Thats why it doesn't work on your website, because the elements are not adjacent. However, you can achieve this mouseover interaction with js.
In "custom html& css" -> "custom <head> content":
<script>
jQuery(document).on("mouseenter", ".hoverme", function(event) {
jQuery(".showme").show();
});
jQuery(document).on("mouseleave", ".hoverme", function(event) {
jQuery(".showme").hide();
});
</script>
In the above example i didnt use your id's but used some classes "showme" and "hoverme"
