.middle-box {
    margin: auto;
    margin-top: 60px;
    width: 500px;
    padding: 30px;
    box-shadow: 5px 10px 18px #888888;
    border-radius: 20px;
}

.on-mobile button {
    margin-bottom: 10px;
}

.fit-screen {
    /*width: calc(100vw - 17rem);*/
    height: calc(100vh - 8.5rem);
}

@media (max-width: 960px) {
    .fit-screen {
        height: calc(100vh - 5.5rem);
    }
    .on-mobile {
        display: none;
    }
}

@media (max-width: 642px) {
    .fit-screen {
        /*width: calc(100vw - 3rem);*/
        height: calc(100vh - 5.5rem);
    }
    .on-mobile {
        display: none;
    }
}