.btn1 {
    margin: 2px;
    padding: 2px;
    width: 32px;
    height: 32px;
    float: left;
    cursor: pointer;
    border: 1px solid gray;
    background-color: #ccc;
    color: white;
    padding: 3px;
}
.btn1:hover { }
.btn2 {
    margin: 2px;
    padding: 2px;
    width: 32px;
    height: 32px;
    float: left;
    cursor: pointer;
    border: 1px solid gray;
    background-color: #cco;
    color: white;
    padding: 3px;
}
.btn2:hover { }

<div>
    <button class="btn1"></button>
</div>
<div>
    <button class="btn2"></button>
</div>