CSS样式
//不只是a标签，其他有下划线的字体也可以
a:hover{
color: #ff3100; //这里的颜色是指字体颜色不是波浪下划线效果的svg图颜色
text-decoration: none;
background:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 4'%3E%3Cpath fill='none' stroke='%23ff3300' d='M0 3.5c5 0 5-3 10-3s5 3 10 3 5-3 10-3 5 3 10 3'/%3E%3C/svg%3E") repeat-x 0 100%
background-size: 20px auto;
animation: waveMove 1s infinite linear;
}
url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 4'%3E%3Cpath fill='none' stroke='%23ff3300' d='M0 3.5c5 0 5-3 10-3s5 3 10 3 5-3 10-3 5 3 10 3'/%3E%3C/svg%3E") repeat-x 0 100%