css文字效果，文字顏色有光影流動

.sq_start {    position: absolute;    bottom: 10%;    left: 50%;    z-index: 3;    margin-left: -50px;    width: 100px;    height: 20px;    font-size: 18px;    background: -webkit-gradient(linear,left top,right top,color-stop(0, #549A66),color-stop(0.3, #3CAF5A),color-stop(0.5, white),color-stop(0.7, #3CAF5A),color-stop(1, #3CAF5A));    background-clip: text;    -webkit-background-clip: text;    -webkit-text-fill-color: transparent;    text-fill-color: transparent;    -webkit-animation: slidetounlock 4s linearinfinite;    animation: slidetounlock 4s linear infinite;}