<!doctype html>
<meta charset="UTF-8">
<style>
  button {
    background-color: rgb(255, 0, 0);
    color: black;
  }

  button:hover {
    background-color: rgb(0, 0, 0);
    color: white;
  }

  .drop-down-menu {
    height: 100px;
    width: 100px;
  }

  .drop-down-menu .menu-items-list {
    display: none;
  }

  .drop-down-menu:hover .menu-items-list {
    display: block;
  }
</style>
<div>
  <button>Test Button</button>
  <div class="drop-down-menu">
    <div class="menu-title">Test Menu</div>
    <ul class="menu-items-list">
      <li class="item-one">One</li>
      <li class="item-two">Two</li>
      <li class="item-three">Three</li>
    </ul>
  </div>
</div>
