.dark-mode {
    background-color:  #2c3c44;
    color: white;
}
.light-mode {
    background-color: white;
    color: black;
}

#cabecera {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: #1a1a1a;
    color: #FFFFFF;
    z-index:2;
    padding-bottom: 5px;
}