.head-center{
    color: aliceblue;
    font-size: 50px;
    width: 100%;
    height: 100vh;
    text-align: center;
    align-content: center;
}
.head-center>.diyihang {
    display: block;
    font-size: 1.5rem;
    word-spacing: 1rem;
}
.head-center>.dierhang {
    display: block;
    font-size: 5rem;
}
.head-center>form>a>.disanhanganniu {
    display: inline-block;
    font-size: 1rem;
    width: 10rem;
    height: 3rem;
    border-radius: 2rem;
    background-color: rgb(90, 90, 214);
}
.head-center>form>a>.disanhanganniu:hover {
    background-color: rgb(53, 53, 211);
    cursor: pointer;
}