@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@500&display=swap');
html, body {
    height: 100%;
    width: 100%;
    padding: 0;
    margin: 0;
    font-family: "JetBrains Mono", monospace;
}

body {
    display: flex;
    flex-direction: column;
}
p, ol, ul {
    margin: 10px 0px;
}
#language_menu {
    font-size: 30px;
    display: block;
    text-align: center;
}
header {
    height: 100px;
    opacity: 80%;
    color: white;
    font-size: 56px;
    text-align: center;
    align: middle;
    padding: 50px;
}
main {
    flex: auto;
    background-color: #ccc;
    width: 800px;
    margin: 0 auto;
    padding: 10px;
}
footer {
    height: 100px;
}
header, footer {
    background-color: black;
}
@media only screen and (max-width:800px) {
    footer {
        display: none;
    }
    main {
        width: 100%;
    }
}
header {
    height: mobile;
}