@media screen and (max-width: 572px) {
    header {
        overflow: initial;
    }

    header .container {
        display: none;
    }

    header .container-responsive {
        display: block;
    }

    header .logo {
        justify-content: start;
        height: 100px;
        width: 250px;
        margin: 0;
        background-size: 125px;
        background-position: left top;
        z-index: 10;
    }

    header .logo>* {
        font-weight: bold;
        text-align: left;
        margin: 0;
    }

    header h1 {
        font-size: 20px;
        text-align: left;
    }

    header .container-responsive .logo {
        position: absolute;
        left: 15px;
        top: 2px;
    }

    header .container-responsive nav ul {
        display: block;
        text-align: left;
        font-size: 1.5em;
        margin: 90px 0 0 0;
    }

    header .container-responsive nav ul li {
        padding: 20px 0;
    }

    header .container-responsive nav ul li a {
        margin: 0 30px 0 0;
    }

    header .container-responsive nav ul li.active a,
    header .container-responsive nav ul li a:hover {
        color: var(--color_primary);
        font-weight: bold;
    }

    header .container-responsive nav ul li.active a {
        border-style: solid;
        border-width: 0 0 3px 0;
        border-color: var(--color_primary);
    }

    section {
        padding: 15px;
        border-top: 0 !important;
    }

    section:nth-child(1n),
    section:nth-child(2n) {
        transform: initial;
        box-shadow: none;
        background-color: transparent;
        border: none;
    }

    section#intro {
        align-items: center;
        margin-top: 130px;
        padding: 20px;
        background-image: none;
    }

    section#contact {
        padding-top: 110px;
    }

    section#about {
        padding-top: 40px;
        padding-bottom: 300px;
        background-size: 300px;
    }

    .cloud {
        margin-top: 150px;
    }

    section#references .reference>* {
        width: 100%;
    }

    section#references .reference img,
    section#references .reference:nth-child(odd) img {
        margin: 0;
        width: 100%;
    }

    section#wrapper-projects {
        margin-top: 130px;
    }

    section#wrapper-projects .reference {
        -webkit-box-orient: vertical;
        -webkit-box-direction: normal;
        -ms-flex-direction: column;
        flex-direction: column;
        -webkit-box-align: center;
        -ms-flex-align: center;
        align-items: center;
    }

    section#wrapper-projects .reference>* {
        width: 100%;
    }

}

/* Burger menu ----- */

header .container-responsive {
    position: relative;
    height: 110px;
    z-index: 10;
}

header .container-responsive .checkbox {
    position: fixed;
    display: block;
    height: 32px;
    width: 32px;
    top: 30px;
    right: 20px;
    z-index: 5;
    opacity: 0;
    cursor: pointer;
}

header .container-responsive .burger-lines {
    display: block;
    height: 26px;
    width: 32px;
    position: fixed;
    top: 27px;
    right: 20px;
    z-index: 2;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

header .container-responsive .burger-lines .line {
    display: block;
    height: 4px;
    width: 100%;
    border-radius: 10px;
    background: var(--color_primary);
}

header .container-responsive .burger-lines .line1 {
    transform-origin: 0% 0%;
    transition: transform 0.4s ease-in-out;
}

header .container-responsive .burger-lines .line2 {
    transition: transform 0.2s ease-in-out;
}

header .container-responsive .burger-lines .line3 {
    transform-origin: 0% 100%;
    transition: transform 0.4s ease-in-out;
}

header .container-responsive nav {
    position: fixed;
    padding-top: 100px;
    box-shadow: 0 0 6px 0px rgb(50 50 50 / 50%);
    height: 100vh;
    width: 100%;
    max-width: 500px;
    transform: translate(-150%);
    display: flex;
    flex-direction: column;
    margin-left: -35px;
    padding-left: 90px;
    transition: transform 0.5s ease-in-out;
    text-align: center;
    background-color: var(--bg_secondary);
}

header .container-responsive input[type="checkbox"]:checked~nav {
    transform: translateX(0);
}

header .container-responsive input[type="checkbox"]:checked~.burger-lines .line1 {
    transform: rotate(45deg);
}

header .container-responsive input[type="checkbox"]:checked~.burger-lines .line2 {
    transform: scaleY(0);
}

header .container-responsive input[type="checkbox"]:checked~.burger-lines .line3 {
    transform: rotate(-45deg);
}

header .container-responsive input[type="checkbox"]:checked~a .logo {
    position: fixed;
}

/* ----- Burger menu */