@media only screen and (min-height: 360px) and (max-height: 480px) {
    header {
        height: 15%;
    }

    content{
        top: 15%;
        bottom: 15%;
    }

    footer {
        height: 15%;
    }

    .content_left {
        display: none;
    }

    .content_right {
        display: none;
    }

    .content_main {
        width: 100%;
    }

    .menu {
        height: auto;
        width: 100%;
    }

    .logo {
        width: calc(100% - 10px);
        padding-left: 0;
        padding-right: 0;
        text-align: center;
    }

    .element {
        width: calc(100% - 10px);
        padding-left: 0;
        padding-right: 0;
        text-align: center;
        display: none;
    }

    .menu:hover {
        height: auto;
        background-color: cadetblue;
    }

    .menu:hover .element {
        display: block;
    }

    content ul li {
        width: calc((100% - 20px)/2);
    }
}

@media only screen and (min-width: 360px) and (max-width: 480px) {

    header {
        height: 10%;
    }

    content{
        top: 10%;
        bottom: 10%;
    }

    footer {
        height: 10%;
    }

    .menu {
        height: auto;
        width: 100%;
    }

    .logo {
        width: calc(100% - 10px);
        padding-left: 0;
        padding-right: 0;
        text-align: center;
    }

    .element {
        width: calc(100% - 10px);
        padding-left: 0;
        padding-right: 0;
        text-align: center;
        display: none;
    }

    .menu:hover {
        height: auto;
        background-color: cadetblue;;
    }

    .menu:hover .element {
        display: block;
    }

    .content_left {
        display: none;
    }

    .content_right {
        display: none;
    }

    .content_main {
        width: 100%;
    }

    content ul li {
        width: calc(100% - 10px);
    }
}