html,body{
    width:100%;height:100%;margin:0px;padding:0px;
}
body{
    display:flex;justify-content:center;align-items:center;
}
div{
    font-family:"微软雅黑", "Verdana", "Arial", "Helvetica", "sans-serif";color:#333;font-size:12px;
}
.d1 {
    padding:10px;border-radius:5px;box-shadow:0 0 3pc rgba(0, 0, 0, 0.4);
}