#topbar{
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #ffffff;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    height: 60px;
    /* 悬浮置顶 */
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000
}

#sidebar{
    margin-top: 60px;
}

#page-container{
    margin-top: 60px;
}

#zoom-in{
    width: 60px;
}

#zoom-out{
    width: 60px;
}

.top-btn{
    display: inline-block;
    padding: 0 20px;
    height: 60px;
    line-height: 60px;
    color: #333;
    font-size: 16px;
    cursor: pointer;
    transition: all .3s;
    border: 0;
    background-color: #ffffff;
    transition: all .3s;
}

.top-btn:hover{
    background-color: #f5f5f5;
}

::-webkit-scrollbar-thumb {
    border-radius: 10px;
    -webkit-box-shadow: 0 0 6px rgba(0, 0, 0, .3);
    background-color: #ffffffbd;
}
::-webkit-scrollbar {
    width: 5px;
    height: 16px;
    background-color: rgb(0 0 0 / 0%);
}