.josefin-sans-maths {
    font-family: "Josefin Sans", sans-serif;
    font-optical-sizing: auto;
    font-weight: 500;
    font-style: normal;
}

body {
    background-size: cover;
    background-image: url(/assets/images/pizarra-blanca-con-formulas-big.jpg);
    background-repeat: no-repeat;
    background-position: top center;
    background-attachment: fixed;
    color: #333333;
}
div#header {
    background-color: rgba(255, 255, 255,0.95);
    text-align: center;
}
div#content {
    background-color: rgba(255, 255, 255,0.95);
    /*max-width: 640px;*/
    /*width: max-content;*/
    margin-left: auto;
    margin-right: auto;
    /*padding: 10px;*/
}

.nav_icon{
    filter: invert(30%) sepia(100%) saturate(742%) hue-rotate(164deg) brightness(100%) contrast(170%)
}