CSS Gradient Animation

my.css

background: linear-gradient(270deg, #29e4b4, #e429dd);
background-size: 400% 400%;
-webkit-animation: bg-anim 30s ease infinite;
-moz-animation: bg-anim 30s ease infinite;
-o-animation: bg-anim 30s ease infinite;
animation: bg-anim 30s ease infinite;
@-webkit-keyframes bg-anim {
    0%{background-position:0% 50%}
    50%{background-position:100% 50%}
    100%{background-position:0% 50%}
}
@-moz-keyframes bg-anim {
    0%{background-position:0% 50%}
    50%{background-position:100% 50%}
    100%{background-position:0% 50%}
}
@-o-keyframes bg-anim {
    0%{background-position:0% 50%}
    50%{background-position:100% 50%}
    100%{background-position:0% 50%}
}
@keyframes bg-anim {
    0%{background-position:0% 50%}
    50%{background-position:100% 50%}
    100%{background-position:0% 50%}
}