library_books<div class="dropdown">
  <button class="dropbtn">Dropdown</button>
  <div class="dropdown-content">
    <a href="#">Link 1</a>
    <a href="#">Link 2</a>
    <a href="#">Link 3</a>
  </div>
</div>

library_books<style>
.dropdown{
    position: relative;
    display: inline-block;
}
.dropbtn {
    background-color:#9575cd;
    color: white;
    padding: 16px;
    font-size: 16px;
    border: none;
    cursor: pointer;
}
.dropdown-content{
    display: none;
    position: absolute;
    box-shadow:0 2px 4px rgba(0,0,0,0.3);
    background-color: #f9f9f9;
    min-width: 160px;
}
.dropdown-content a {
    color: #1f1f1f;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
}
.dropdown-content a:hover {background-color: #d1c4e9}
.dropdown:hover .dropdown-content {display: block;}
.dropdown:hover .dropbtn {background-color: #b39ddb;}
</style>