* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --background-color: #212121;
    --foreground-color: white;
    --focus-color: #4a90e2;
}

html, body {
    height: 100%;
    scroll-behavior: smooth;
    scroll-padding-top: 25px;
}

body {
    display: flex;
    flex-direction: column;
    font-family: 'Work Sans', sans-serif;
    background: linear-gradient(90deg, #212121, black);
    color: var(--foreground-color);
}

main {
    flex: 1 0 auto;
}

.button {
    font-size: 25px;
    background-color: white;
    color: black;
    padding: 10px 15px;
    border-radius: 10px;
    box-shadow: 0px 0px 15px 0px rgba(0, 0, 0, 0.5);
    cursor: pointer;
    -webkit-user-select: none;
    user-select: none;
    border: none;
}

/* Skip link für Navigation mit Tastatur */
.skip-link {
    position: absolute;
    left: 0;
    background: var(--focus-color);
    color: white;
    padding: 8px;
    z-index: 100;
    top: -100%;
    height: 1px;
    width: 1px;
    overflow: hidden;
    white-space: nowrap;
    transition: top .3s ease;
}
.skip-link:focus {
    top: 0;
    height: auto;
    width: auto;
    overflow: visible;
    white-space: normal;
}

a:focus, button:focus, [tabindex]:focus {
    outline: none;
}

/* Focus für Navigation mit Tastatur */
a:focus-visible, button:focus-visible, [tabindex]:focus-visible {
    outline: 3px solid var(--focus-color);
    outline-offset: 3px;
}


/* Menü */

header {
    width: 90%;
    max-width: 1100px;
    margin: auto;
    z-index: 4;
}

.nav-bar {
    display: flex;
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
    padding: 25px 0;
}

.head-title {
    font-size: 35px;
    font-weight: 500;
    text-decoration: none;
    color: var(--foreground-color);
}

.nav-bar nav ul {
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: 50px;
    justify-content: space-around;
}

.nav-bar nav ul li {
    list-style: none;
}

.nav-bar nav ul li a {
    text-decoration: none;
    color: var(--foreground-color);
    font-size: 20px;
    cursor: pointer;
    transition: font-size .3s, color .3s;
}

.nav-bar nav ul li a:hover {
    font-size: 20.5px;
    color: darkgray;
}

.lang-switch {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.selected-lang {
    color: darkgray!important;
}

/* Make sure menu button is accessible */
#mobile-menu-btn {
    position: fixed;
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 60px;
    height: 60px;
    top: 15px;
    right: 15px;
    padding: 17.5px 15px;
    background-color: #212121;
    box-shadow: 0px 0px 15px 0px rgba(0, 0, 0, 0.5);
    border-radius: 200px;
    cursor: pointer;
    z-index: 5;
}

#mobile-menu-btn hr {
    border: 1.5px solid white;
    border-radius: 2px;
    transition: transform .3s, opacity .3s;
}

.mobile-menu-shown hr:first-of-type {
    transform: translateY(11px) rotate(-45deg);
}

.mobile-menu-shown hr:nth-of-type(2) {
    opacity: 0;
}

.mobile-menu-shown hr:last-of-type {
    transform: translateY(-11px) rotate(45deg);
}

@media only screen and (max-width: 750px) {
    .nav-bar nav {
        position: fixed;
        display: none;
        width: 100%;
        height: 100%;
        left: 0;
        top: 0;
        background-color: rgba(33, 33, 33, 0.95);
        -webkit-backdrop-filter: blur(15px);
        backdrop-filter: blur(15px);
    }

    .nav-shown {
        display: flex!important;
    }

    .nav-bar nav ul {
        flex-direction: column;
        justify-content: center;
        width: 100%;
        height: 100%;
    }

    .nav-bar nav ul li a {
        font-size: 30px;
        font-weight: 500;
    }

    .nav-bar nav ul li a:hover {
        font-size: 30px;
        color: white;
    }

    #mobile-menu-btn {
        display: flex;
    }
}

@media (pointer: coarse) { 
    #mobile-menu-btn:focus-visible:not(:active) {
        outline: 3px solid var(--focus-color);
    }
}


/* Footer */

footer {
    display: flex;
    flex-direction: row;
    justify-content: space-between;
    width: 90%;
    max-width: 1100px;
    margin: 50px auto 0 auto;
}

.footer-left-container {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    gap: 15px;
    margin-bottom: 50px;
}

.footer-text-container {
    display: flex;
    flex-direction: column;
    gap: 15px;
    width: 75%;
}

.footer-title {
    font-size: 30px;
    font-weight: 600;
}

.footer-description {
    font-size: 20px;
    color: darkgray;
}

.footer-right-container {
    display: flex;
    flex-direction: row;
    gap: 100px;
}

.footer-links-container {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.footer-links-container a {
    font-size: 18px;
    color: darkgray;
    text-decoration: none;
    transition: color .3s;
}

.footer-links-container a:hover {
    color: white;
    text-decoration: underline;
}

.footer-link-title {
    font-size: 25px;
    font-weight: 500;
    margin-bottom: 15px;
}

.footer-link-social-container {
    display: flex;
    flex-direction: row;
    gap: 15px;
}

.footer-link-social-container img {
    width: 30px;
    height: 30px;
    -webkit-filter: brightness(75%);
    filter: brightness(75%);
    transition: transform .3s, -webkit-filter .3s, filter .3s;
}

.footer-link-social-container img:hover {
    -webkit-filter: brightness(100%);
    filter: brightness(100%);
    transform: scale(1.1);
}

@media only screen and (max-width: 900px) {
    footer {
        flex-direction: column;
        gap: 50px;
        width: 90%;
    }

    .footer-title {
        font-size: 25px;
    }

    .footer-description {
        font-size: 17.5px;
    }

    .footer-link-title {
        font-size: 22.5px;
    }

    .footer-left-container {
        margin-bottom: 0;
    }

    .footer-right-container {
        flex-direction: column;
        gap: 35px;
        margin-bottom: 50px;
    }
}