body {
    padding: 0;
    margin: 0;
}
html,
body,
#mapid {
    height: 100%;
}

#introduce{
    display: none;
    z-index: 10000;
    height: 80vh;
    width: 80vw;
    background-color: whitesmoke;
    -webkit-box-shadow: 10px 10px 36px 0px rgba(0,0,0,0.88);
    -moz-box-shadow: 10px 10px 36px 0px rgba(0,0,0,0.88);
    box-shadow: 10px 10px 36px 0px rgba(0,0,0,0.88);
    position: absolute;
    left: 50%;
    margin-left: -40vw;
    top: 50%;
    margin-top: -40vh;
}
#top{
    margin: 5px;
    display: flex;
    flex-flow: row;
    justify-content: space-between;
}
#close img{
    color: red;
    cursor: pointer;
}
iframe{
    margin-top: 2.4rem;
    overflow: hidden;
    border: 0;
    height: calc(80vh - 2.4rem);
    left: 0;
    position: absolute;
    top: 0;
    width: 100%;
}