@media only screen and (max-width: 900px) {
    main {
        margin: 1rem;
        padding-top: 1.5rem;
    }

    div.left-side {
        position: relative;
        top: 0;
        left: 0;
        max-width: 100%;
        margin: 6rem 4rem 0;
        filter: none;
    }

    div.left-side section.menu button {
        display: inline-block;
    }

    div.left-side section.menu ul {
        display: none;
    }

    div.left-side section.menu ul.menu li ul.sub-menu {
        position: static;
        padding: 1rem 0;
        background-color: #fff;
    }

    div.left-side section.menu ul.menu li ul.sub-menu.visible {
        display: block;
    }

    div.left-side section.menu ul.menu li ul.sub-menu li.url {
        list-style-type: disc;
        margin-left: 1rem;
    }

    header div.line {
        margin: 0% 2%;
    }

    nav.news .new p.tldr {
        display: none;
    }

    nav.news .new:hover p.tldr {
        display: none;
    }

    nav.articles a.article {
        width: auto;
        margin-bottom: 1rem;
    }

    h1,
    h2,
    h3,
    h4,
    h5,
    h6 {
        padding: 1rem;
    }

    article table {
        font-size: 0.75rem;
    }

    article th,
    article td {
        padding-left: 0.1rem;
        padding-right: 0.1rem;
    }

    section.test,
    section.questionary {
        padding: 0.5rem;
        font-size: 0.85rem;
    }

    article table.big {
        font-size: 0.5rem;
    }

    footer {
        margin: 1rem auto;
    }

    aside .feedback {
        position: relative;
        width: 100%;
        max-width: 85%;
        margin: 2rem;
        padding: 1rem;
        bottom: 0;
        left: 0;
    }
    .breadcrumbs,
    .hub-nav-block,
    .subhub-nav-block {
        max-width: none;
        margin-left: 1rem;
        margin-right: 1rem;
    }

    .hub-nav-list,
    .subhub-nav-list {
        gap: 0.4rem;
    }
}

@media only screen and (max-width: 440px) {
    section {
        padding: 0.5rem;
    }

    header div.line span.logo {
        display: none;
    }

    div.left-side {
        max-height: 70%;
        margin: 6rem 1rem 0;
    }

    nav.news h3 {
        font-size: 1.1rem;
        margin-bottom: 0.5rem;
    }

    nav.articles .article {
        width: 100%;
    }

    nav.articles .article:nth-of-type(2n - 1) {
        margin-right: 0;
    }

    main {
        margin: 0;
    }

    main p {
        margin: 0.5rem;
    }

    main article {
        padding: 0.5rem;
    }

    main p.tldr {
        margin: 0;
    }

    article > h2 {
        font-size: 1.5rem;
    }

    article > h3 {
        font-size: 1.2rem;
    }

    article > h4 {
        font-size: 1.1rem;
    }

    article > p {
        font-size: 1.2rem;
    }

    footer {
        max-width: 100%;
        margin: 1rem;
    }
    .breadcrumbs {
        margin-top: 1rem;
        padding: 0 0.75rem;
    }

    .hub-nav-block,
    .subhub-nav-block {
        margin: 1rem 0.75rem;
        padding: 0.75rem;
    }

    .hub-nav-link,
    .subhub-nav-link {
        font-size: 0.85rem;
    }
}