Fancy Button Animation

<!DOCTYPE html>
<title>Fancy Button Animation</title>
<style>
  body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: #fcf3ec;
  }
  .button {
    --offset: 10px;
    --border-size: 2px;
    display: block;
    position: relative;
    padding: 1.5em 3em;
    -webkit-appearance: none;
      -moz-appearance: none;
        appearance: none;
    border: 0;
    background: transparent;
    color: #e55743;
    text-transform: uppercase;
    letter-spacing: .25em;
    outline: none;
    cursor: pointer;
    font-weight: bold;
    border-radius: 0;
    box-shaddow: inset 0 0 0 var(--border-size) currentcolor;
    transition: background .8s ease;
  }
  .button:hover {
    background: rgba(100, 0, 0, 0.03);
  }
  .button_horizontal, .button_vertical {
    position: absolute;
    top: var(--horizontal-offset, 0);
    right: var(--vertical-offset, 0);
    bottom: var(--horizontal-offset, 0);
    left: var(--vertical-offset, 0);
    transition: -webkit-transform .8s ease;
    transition: transform .8s ease;
    transition: transform .8s ease, -webkit-transform .8s ease;
    will-change: transform;
  }
  .button_horizontal::before, .button_vertical::before {
    content: '';
    position: absolute;
    border: inherit;
  }
  .button_horizontal {
    --vertical-offset: calc(var(--offset) * -1);
    border-top: var(--border-size) solid currentcolor;
    border-bottom: var(--border-size) solid currentcolor;
  }
  .button_horizontal::before {
    top: calc(var(--vertical-offset) - var(--border-size));
    bottom: calc(var(--vertical-offset) - var(--border-size));
    left: calc(var(--vertical-offset) * -1);
    right: calc(var(--vertical-offset) * -1);
  }
  .button:hover .button_horizontal {
    -webkit-transform: scaleX(0);
            transform: scaleX(0);
  }
  .button_vertical {
    --horizontal-offset: calc(var(--offset) * -1);
    border-left: var(--border-size) solid currentcolor;
    border-right: var(--border-size) solid currentcolor;
  }
  .button_vertical::before {
    left: calc(var(--horizontal-offset) - var(--border-size));
    right: calc(var(--horizontal-offset) - var(--border-size));
    top: calc(var(--horizontal-offset) * -1);
    bottom: calc(var(--horizontal-offset) * -1);
  }
  .button:hover .button_vertical {
    -webkit-transform: scaleY(0);
            transform: scaleY(0);
  }
</style>
<body>
  <button class="button">Fancy Button
    <div class="button_horizontal"></div>
    <div class="button_vertical"></div>
  </button>
</body>