按钮逐渐覆盖颜色的css写法

按钮逐渐覆盖颜色的css写法

.market_container_left .button span:hover:after{
    border-width: 248px 248px 0 0;

}
.market_container_left .button span:hover{
    color: #3D3D3D;
}
.market_container_left .button span:after{
    content: '';
    width: 0;
    height: 0;
    -webkit-transform: rotate(360deg);
    border-style: solid;
    border-width: 0 0 0 0;
    border-color: #FDC800 transparent transparent transparent;
    position: absolute;
    top: 0;
    left: 0;
    box-sizing: border-box;
    -webkit-transition: 0.5s;
    transition: 0.5s;
    z-index: -1;
    color: #474C3C;
}