Solution 1 :

I changed .Block:hover to use vh (veiwport height) as shown here:

.Block:hover {
  width: 34%;
  height: 90vh;
}
.Block {
  display: inline-block;
  padding: 2px;
  margin: 2px;
  vertical-align: top;
  width: 90%;
  background-color: yellow;
  color: black;
}

.Block:hover {
  width: 34%;
  height: 90vh;
}
<button onclick="location.href='https://website.com'" class="Block">Website</button>

Solution 2 :

Height in percentage value is tricky. You’re currently asking the button to take up 90% of the parent element’s height on hover. If there is not a fixed height set on the parent (i.e. it is set to auto which is default), then you can’t expect the height declaration to know what to take 90% of.

If you give the parent element a fixed height, then the button can grow in height based on the percentage of that height. Down below I added height: 100px to the parent element, and it now responds on hover

.Block {    
    display: inline-block;
    padding: 2px;
    margin: 2px;
    vertical-align: top;
    width: 90%;
    height: auto;
    background-color: yellow;
    color: black;
}

.Block:hover {    
    display: inline-block;
    padding: 2px;
    margin: 2px;
    vertical-align: top;
    width: 34%;
    height: 90%;
    background-color: yellow;
    color: black;
}

div {
  height: 100px;
}
<div>
  <button onclick="location.href='https://website.com'" class="Block">Website</button>
</div>

As a word about nomenclature, “responsive” usually refers to the layout changing with viewport size, not about user interaction with the page. Confusing, I know.

Problem :

So I’ve been trying to make a responsive button and i managed to make width but not height here’s my html:

.Block {    
    display: inline-block;
    padding: 2px;
    margin: 2px;
    vertical-align: top;
    width: 90%;
    height: auto;
    background-color: yellow;
    color: black;
}

.Block:hover {    
    display: inline-block;
    padding: 2px;
    margin: 2px;
    vertical-align: top;
    width: 34%;
    height: 90%;
    background-color: yellow;
    color: black;
}
<button onclick="location.href='https://website.com'" class="Block">Website</button>

and it’s not responsive with height

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