.navbar-collapse:after, .navbar-collapse:before, .navbar-header:after, .navbar-header:before, .navbar:after, .navbar:before, .pager:after, .pager:before {
    display: none;
    content: " ";
}
body{
    background-image:url(../img/even-background.jpg);
    background-repeat: no-repeat;
    background-size:cover;
    background-position: center center;
    margin: 0 auto;
}
.main-footer{
    visibility: hidden;
}
.navbar-brand>img {
    height: 44px;
}
.navbar {
    height: 70px;
}
/* Selecciona cualquier <input> requerido */
input:required {
  border: 2px solid red;
}
input:valid {
  border: 2px solid green;
}