Why does my CSS selector does not work as expected? - html

Question

I am creating a gallery website my goal is the show option button on bottom of the picture when use hover over it.
Here is an example of what I want on pixabay
<div class="image-thumbnail col-lg-2 col-md-4 col-xs-6 thumb">
<a class="thumbnail" href="#">
<img class="img-responsive" src="http://placehold.it/400x300" alt="">
</a>
<div class="image-options">
<div class="btn-group" role="group">
<button type="button" class="btn btn-sm ">
<i class="fa fa-thumbs-up"></i>
</button>
<button type="button" class="btn btn-sm ">
<i class="fa fa-thumbs-down"></i>
</button>
<button type="button" class="btn btn-sm">
<i class="fa fa-facebook"></i>
</button>
<button type="button" class="btn btn-sm">
<i class="fa fa-google-plus"></i>
</button>
<button type="button" class="btn btn-sm">
<i class="fa fa-twitter"></i>
</button>
</div>
</div>
</div>
CSS
div.image-thumbnail div.image-options {
position: absolute;
z-index: 2000;
margin-top: -55px;
margin-left: 1px;
display: none;
}
div.image-thumbnail div.image-options:hover {
display: inline;
}
Any ideas ?
EDIT:
It turns out that
div.image-thumbnail div.image-options {
position: absolute;
z-index: 2000;
margin-top: -55px;
margin-left: 1px;
display: none;
}
Don't work at all as the image-options are still visible even with display:none

Answer 1

You can't hover element with display: none, it's not visible. Instead you should define :hover rule on .image-thumbnail element:
.image-thumbnail {
position: relative;
}
.image-thumbnail .image-options {
position: absolute;
z-index: 2000;
margin-top: -55px;
margin-left: 1px;
display: none;
}
.image-thumbnail:hover .image-options {
display: inline;
}

Answer 2

As stated in my comment.
div.image-thumbnail div.image-options:hover {
display: inline;
}
This is saying when we hover over div.image-options display it... This isn't possible. (As you have it set to display: none) plus this is not the element you want to set the hover on.
What you mean to say is
div.image-thumbnail:hover div.image-options {
display: inline;
}
When we hover over div.image-thumbnail then show div.image-options.