body {
    overflow: auto;
}
.header {
    margin-bottom: 100px;
}
main {
    display: flex;
    flex-direction: column;
    max-width: 50%;
    width: 100%;
    align-items: start;
}
#main-page-button {
    min-height: 50px;
    height: 50px;
}

@media screen and (max-width: 800px) {
    .header {
        margin-bottom: 30px;
    }
    header {
        text-align: center;
    }
    main {
        max-width: 100%;
        padding: 0 20px 0 20px;
    }
}