li > a padding is not filling parent li div

Question

I want to add padding to my "a" element which will decide the height for the parent div. Although if I add it, the parent div remains unaffected. I cannot seem to figure it out at all.

It is a hamburger navbar menu. So when I click my icon, it should bring the navbar down and should be the same height that the "a" tag provides through padding.

<div id="side-menu" class="side-nav" v-bind:class="{'side-menu-open': isOpen}">
    <ul class="side">
        <li class="side"><a href="#">Home</a></li>
        <li class="side"><a href="#">About</a></li>
        <li class="side"><a href="#">Projects</a></li>
        <li class="side"><a href="#">Contact</a></li>
    </ul>
</div>


li.side {
    display:inline-block;
    margin-right: -4px;
}

li.side a {
    padding: 3em 2em;
    border-bottom: 1px solid #333;
    display: block;
    color: #fff;
    text-decoration: none;
    transition: 0.3s ease;
}

li.side a:first-child {
    border-top: 1px solid #333;
}

li.side a:hover {
    background-color: #333;
    transition: 0.3s ease;
}

.side-nav {
    transition: 0.4s;
    background-color: #222;
    width: 100% !important;
    height:0;
    position: fixed;
    z-index: 1;
    top: 0;
    left: 0;
    overflow: hidden;
}

.open {
    transition: 1s;
}

.side-menu-open {
    height: 70px !important;
}

.open-slide {
    transition: 0.4s;
}

.open-slide:hover {
    cursor: pointer;
}

Answer 1

You need to change the height from a fixed value to auto here.

.side-menu-open {
    height: auto;
}

By default, a is an inline element. Top and bottom padding will not apply. You can change the display type to inline-block.

li.side {
  display: inline-block;
  margin-right: -4px;
}

li.side a {
  padding: 3em 2em;
  border-bottom: 1px solid #333;
  color: #fff;
  text-decoration: none;
  transition: 0.3s ease;
  /* added */
  display: inline-block;
}

li.side a:first-child {
  border-top: 1px solid #333;
}

li.side a:hover {
  background-color: #333;
  transition: 0.3s ease;
}

.side-nav {
  transition: 0.4s;
  background-color: #222;
  width: 100% !important;
  /*height: 0;*/
  position: fixed;
  z-index: 1;
  top: 0;
  left: 0;
  overflow: hidden;
}

.open {
  transition: 1s;
}

.side-menu-open {
  height: auto !important;
}

.open-slide {
  transition: 0.4s;
}

.open-slide:hover {
  cursor: pointer;
}

<div id="test">
  <div id="side-menu" class="side-nav" v-bind:class="{'side-menu-open': isOpen}">
    <ul class="side">
      <li class="side"><a href="#">Home</a></li>
      <li class="side"><a href="#">About</a></li>
      <li class="side"><a href="#">Projects</a></li>
      <li class="side"><a href="#">Contact</a></li>
    </ul>
  </div>
</div>