@media only screen and (max-width: 19200px) {
    html {
        font-size: 1px !important;
    }
}

@media only screen and (max-width: 1440px) {
    html {
        font-size: 0.75px !important;
    }
}

html, body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    min-width: 1200rem;
    font-size: 14rem;
    color: #333;
}
#app {
    height: calc(100% - 40rem);
}
    #app > .main {
        position: absolute;
        left: 0;
        right: 0;
        width: 400px;
        margin: auto;
        top: 50%;
        transform: translateY(-50%);
    }