#modal {
    width: 100%;
    height: 100%;
    position: fixed;
    left: 0;
    top: -100%;
    z-index: 10000000000;
    overflow: hidden;
    background-color: #f2efef;
    -webkit-transition: all 0.5s ease;
    -moz-transition: all 0.5s ease;
    transition: all 0.5s ease;
    margin: 0;
    padding: 0;
}

#modal.activo {
    top: 0;
}

#modal a {
    width: 65px;
    height: 65px;
    position: absolute;
    top: 0;
    right: 0;
    padding: 30px 10px 10px 15px;
    display: block;
    background-color: #000;
}

#modal a::before,
#modal a::after {
    content: '';
    height: 1px;
    width: 40px;
    position: absolute;
    background: #FFF;
}

#modal a::before {
    -webkit-transform: rotate(45deg);
    -moz-transform: rotate(45deg);
    -ms-transform: rotate(45deg);
    transform: rotate(45deg);
}

#modal a::after {
    -webkit-transform: rotate(-45deg);
    -moz-transform: rotate(-45deg);
    -ms-transform: rotate(-45deg);
    transform: rotate(-45deg);
}