Prevent label text from overlapping input text

Question

I created an input field, but when a user clicks off the user input, the span text overlays the input text. How can I prevent this from happening? I feel like I have tried everything!

.label {
  display: inline-block;
  margin: 10px;
}

.form-input {
  margin: 10px;
}

.label span {
  z-index: 1;
  position: absolute;
  cursor: text;
  pointer-events: none;
  color: #999;
  padding-left: 10px;
  line-height: 54px;
  font-family: Arial, Helvetica, sans-serif;
  transition: all ease-out 0.1s;
}

.label:focus-within>span {
  /* Move span text up on focus */
  line-height: 26px;
  font-size: 12px;
  transition: ease-in-out 0.2s;
  color: rgb(29, 161, 242);
}

.label input {
  z-index: 0;
  width: 258px;
  height: 22px;
  padding-bottom: 14px;
  padding-top: 14px;
  padding-left: 9px;
  font-size: 16px;
  font-family: Arial, Helvetica, sans-serif
}

.label input:focus {
  padding-top: 20px;
  padding-bottom: 8px;
  transition: all ease-in-out 0.1s;
}

<div>
  <form class='form-input'>
    <label class='label'>
      <span class='span-text'>Email</span>
      <input value=''></input>
    </label>
  </form>
</div>

Codepen: https://codepen.io/pen?template=GROaJZM