CSS
body {
margin: 0;
padding: 0;
background: #000;
}
a {
position: absolute;
left: 50%;
top: 50%;
transform: translate(-50%, -50%);
width: 200px;
height: 60px;
text-align: center;
line-height: 60px;
color: #fff;
font-size: 24px;
text-transform: uppercase;
text-decoration: none;
font-family: sans-serif;
background:linear-gradient(90deg, #03a9f4,
#f441a5, #ffeb3b, #03a9f4);
background-size:400%;
border-radius: 30px;
z-index: 1;
transform: .5s;
letter-spacing: 2px;
}
@keyframes hoverbtn {
0%{
background-position: 0%;
}
100% {
background-position: 400%;
}
}
a:hover {
animation: hoverbtn 6s linear infinite;
}
a:before {
content: '';
position: absolute;
top: -5px;
left: -5px;
right: -5px;
bottom: -5px;
z-index: -1;
background: linear-gradient(90deg, #03a9f4,
#f441a5, #ffeb3b, #03a9f4);
background-size: 400%;
border-radius: 40px;
opacity: 0;
transform: .5s;
}
a:hover:before {
filter: blur(20px);
opacity: 1;
animation: hoverbtn 6s linear infinite;
}
HTML
<body>
<a href="">Button</a>
</body>
https://youtu.be/sJk6kHSOf-g
