my-projects-website/app/application/resources/site/scss/app.scss

@import url('https://fonts.googleapis.com/css2?family=Roboto:ital,wght@0,400;0,700;1,400;1,700&display=swap');
@import "reset";
@import "forms";

html,
body {
    height: 100%;
}

body {
    font-family: "Roboto", sans-serif;
    margin: 0;
}

.wrapper {
    display: flex;
    flex-direction: column;
    min-height: 100%;

    .main-container {
        flex: 1 0 auto;
    }

    .section-container {
        display: flex;
        flex: 1 0 auto;
        min-height: 100%;
        flex-direction: column;

        .content {
            flex: 1 0 auto;
        }

        .footer {
            flex: 0 0 auto;
        }
    }
}

.header {
    display: grid;
    grid-template-rows: 1fr;
    grid-template-columns: 1fr 1fr;
    grid-template-areas:
        "logo menu"
        "language language";
    padding: 8px;
    box-shadow: 0 3px 9px rgba(0,0,0,0.48);
    background: #eee;
}
.header_logo {
    grid-area: logo;
    height: 50px;

    a {
        text-decoration: none;
    }

    img {
        max-height: 100%;
    }

    strong {
        color: #0a0e17;
        font-size: 20px;
        display: inline-block;
        vertical-align: middle;
        padding: 5px 10px;
        border: 1px solid #0a0e17;
        border-radius: 4px;
        white-space: nowrap;
    }
}
#mobile-menu {
    grid-area: menu;
    border: 0;
    background: none;
    color: #FF2D20;
    margin-left: auto;
    cursor: pointer;
    position: relative;
    z-index: 110;

    .open {
        display: block;
    }

    .close {
        display: none;
        margin-top: -5px;
    }
}
#menu {
    display: none;

    ul {
        padding: 10px 0 0 20px;
        margin: 0;
        list-style: none;
    }

    a {
        display: block;
        text-decoration: none;
        font-size: 16px;
        padding-top: 10px;
        padding-bottom: 10px;
        color: #0a0e17;
    }

    a.active {
        font-weight: bold;
    }
}
.menu__title {
    background: #ccc;
    font-size: 24px;
    font-weight: bold;
    padding: 12px 0 12px 20px;
    box-shadow: 0 3px 9px rgba(0,0,0,0.48);
}
body.mobile-menu-open {
    #mobile-menu {
        .open {
            display: none;
        }

        .close {
            display: block;
        }
    }
    #menu {
        background: #ddd;
        display: block;
        position: fixed;
        left: 0;
        top: 0;
        overflow: auto;
        width: 100%;
        height: 100%;
        z-index: 100;
    }
}
#language {
    grid-area: language;
    margin-top: 10px;
}
.language__block {
    position: relative;
}
.language__button {
    border: 0;
    box-shadow: 1px 1px 3px rgba(0, 0, 0, 0.48);
    background: #ccc;
    width: 100%;
    cursor: pointer;
    font-size: 18px;
    position: relative;
    padding: 10px;
    border-radius: 5px;
    color: #000;
}
.language__button__str {
    position: absolute;
    top: calc(50% - 8px);
    right: 10px;
}
.language__list {
    background: #ddd;
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    list-style: none;
    box-shadow: 1px 1px 3px rgba(0, 0, 0, 0.48);
    padding: 10px 0;
    margin: 0;
    border-radius: 0 0 5px 5px;
    z-index: 100;

    a {
        text-decoration: none;
        color: #000;
        font-size: 16px;
        display: block;
        padding: 10px 20px;
    }
}
#language.active {
    .language__list {
        display: block;
    }
    .language__button {
        border-radius: 5px 5px 0 0;
    }
}
.main-container {
    display: flex;
    flex-direction: column;
}
.content {
    padding-left: 20px;
    padding-right: 20px;
    margin-bottom: 20px;

    h1 {
        font-size: 24px;
        font-weight: bold;
        padding-bottom: 10px;
        margin-bottom: 10px;
        border-bottom: 1px solid #eee;
    }
}

.footer {
    background-color: #eee;
    padding: 15px 0 15px 15px;
    box-shadow: 5px 0px 5px rgba(0,0,0,0.48);

    a {
        text-decoration: none;
        color: #0a0e17;
        font-size: 18px;
        font-weight: bold;
    }
}

@media (min-width: 1000px) {
    body {
        max-width: 1400px;
        margin: 0 auto;
    }
    .header {
        grid-template-areas: "logo language";
        grid-template-columns: 1fr 200px;
    }
    .header_logo {
        width: 150px;
        margin-left: 12px;
        margin-top: 10px;
        margin-bottom: 10px;
    }
    #mobile-menu {
        display: none;
    }
    .wrapper .section-container {
        flex: auto;
    }
    .main-container {
        flex-direction: row;
    }
    #language {
        margin-right: 10px;
    }
    .language__block {
        margin-top: 6px;
    }
    .language__button {
        padding: 7px 10px 7px 0;
    }
    #menu {
        flex: none;
        background: #eee;
        display: block;
        width: 175px;
        box-shadow: 0px 7px 8px rgba(0,0,0,0.48);
    }
    .menu__title {
        display: none;
    }
}