Animated Neon Buttons In Pure CSS

A set of neon buttons with reflections and animated borders, written in pure CSS/CSS3.

How to use it:

1. The HTML structure for the neon button.

<a href="#">
  <span></span>
  <span></span>
  <span></span>
  <span></span>
  Neon Button
</a>

2. The required CSS styles. Feel free to modify and override the CSS rules below to create your own styles.

a
{
  position: relative;
  display: inline-block;
  padding: 25px 30px;
  margin: 0 20px;
  color: #03e9f4;
  font-size: 24px;
  text-decoration: none;
  text-transform: uppercase;
  overflow: hidden;
  transition: 0.5s;
  letter-spacing: 4px;
  -webkit-box-reflect: below 1px linear-gradient(transparent, #0005);
}
a:hover
{
  background: #03e9f4;
  color: #050801;
  box-shadow: 0 0 5px #03e9f4,
        0 0 25px #03e9f4,
        0 0 50px #03e9f4,
        0 0 200px #03e9f4;
}
a span
{
  position: absolute;
  display: block;
}
a span:nth-child(1)
{
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, #03e9f4);
  animation: animate1 1s linear infinite;
}
@keyframes animate1
{
  0%
  {
    left: -100%;
  }
  50%, 100%
  {
    left: 100%;
  }
}
a span:nth-child(2)
{
  top: -100px;
  right: 0;
  width: 2px;
  height: 100%;
  background: linear-gradient(180deg, transparent, #03e9f4);
  animation: animate2 1s linear infinite;
  animation-delay: 0.25s;
}
@keyframes animate2
{
  0%
  {
    top: -100%;
  }
  50%, 100%
  {
    top: 100%;
  }
}
a span:nth-child(3)
{
  bottom: 0;
  right: -100%;
  width: 100%;
  height: 2px;
  background: linear-gradient(270deg, transparent, #03e9f4);
  animation: animate3 1s linear infinite;
  animation-delay: 0.5s;
}
@keyframes animate3
{
  0%
  {
    right: -100%;
  }
  50%, 100%
  {
    right: 100%;
  }
}
a span:nth-child(4)
{
  bottom: -100%;
  left: 0;
  width: 2px;
  height: 100%;
  background: linear-gradient(360deg, transparent, #03e9f4);
  animation: animate4 1s linear infinite;
  animation-delay: 0.75s;
}
@keyframes animate4
{
  0%
  {
    bottom: -100%;
  }
  50%, 100%
  {
    bottom: 100%;
  }
}