if child elemnt is hovered do changes to the container css

1CSS can not select a parent div only when a specific child or descendent element is hovered.  You'll need some JavaScript to achieve what you seem to want.
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3JavaScript can be added to add something like a "hovered" class to your parent element when various mouse or touch events happen on the child div.  You could edit the CSS properties directly in JavaScript but I would use a CSS class just to keep more of the CSS concerns separate.
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7The :hover is closely related to your question but it doesn't solve your requirements.  :hover lets you select elements that are hovered over.  If the child is hovered, the parent is also hovered.  There is a problem though.
8Here is an example of the problem with :hover:
9HTML:
10<div class="my-parent">
11   <button id="ok">OK</button>
12   <button id="cancel">Cancel</button>
13</div>
14
15CSS:
16.my-parent:hover {
17   background-color: green;
18}
19Say you want the background of my-parent to go red when hovering over "OK".  The above example will do that.  The problem is it'll go green when hovering over the Cancel button too.