@media screen and (max-width:1024px) {
    .P_topbar{
        position: fixed;
        
        top:-3vh;
        left: 2vw;
        width: 96vw;
        min-height: 9vh;
        max-height: 9vh;
    
        border-radius: 15px;
        background-color: white;
        box-shadow:0px 2px 8px 1px gray;

        z-index: 50;
    }

    .topintroduce{
        min-height: 30vh;
    }

    .sidebar{
        top:9vh;
        left:-70vw;
        min-width: 80vw;
        max-width: 80vw;
        min-height: 98vh;
        max-height: 98vh;
    }

    /*消失部分*/
    .topbar{
        display: none;
    }
}

@media screen and (min-width:1024px) {
    .P_topbar{
        display: none;
    }
}