CSS

how to change another element on hover

// If the cube is directly inside the container:
#container:hover > #cube { background-color: yellow; }

// If cube is next to (after containers closing tag) the container:
#container:hover + #cube { background-color: yellow; }

// If the cube is somewhere inside the container:
#container:hover #cube { background-color: yellow; }

// If the cube is a sibling of the container:
#container:hover ~ #cube { background-color: yellow; }

css hover change another element

#a:hover ~ #b {
    background: #ccc
}

<div id="a">Div A</div>
<div>random other elements</div>
<div>random other elements</div>
<div>random other elements</div>
<div id="b">Div B</div>

css hover change other element

#container:hover > #cube { background-color: yellow; }

modify another class on hover

A child element hover cannot effect a parent class or a class elsewhere in the code besides children and siblings. You'll have to use Javascript for that. 

css hover change another element

#a:hover + #b {
    background: #ccc
}

<div id="a">Div A</div>
<div id="b">Div B</div>

css can I move element in another div when hover on another

.hover {
  background-color: blue;
  padding: 8px;
}

.move {
  background-color: red;
  padding: 8px;
  transition: 0.5s;
}

.hover:hover ~ .move {
  margin-top: 48px;
}