style.css

body {
  height: 100%;
  background: #484848;
  overflow-y: hidden;
}
a:hover, a:active {
  text-decoration: none;
}
.navbar-right a {
  font-size: 30px;
}
.nav-menu {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 100vh;
  background: #000;
  display: none;
  animation-name: bounceOutDown;
}
.navbar>.container-fluid .navbar-brand {
  line-height: 30px;
  color: rgba(255, 255, 255, .8);
}
.navbar-inverse .navbar-nav>li>a {
  color: rgba(255, 255, 255, .8);
}
.nav-menu.nav-menu-active {
  animation-name: bounceInUp;
}
.nav-menu a.dismiss-nav {
  font-size: 30px;
  position: absolute;
  right: 15px;
  top: 15px;
  color: rgba(255, 255, 255, .8);
}
.nav-menu a.dismiss-nav:hover {
  color: #fff;
}
.nav-menu .nav-menu-list {
  list-style-type: none;
  padding: 0;
  margin: 0;
  color: #fff;
}
.nav-menu .nav-content {
  position: relative;
  top: 50%;
  transform: translateY(-50%);
}
.nav-menu .nav-title {
  text-transform: uppercase;
  color: #fff;
}
.nav-menu .nav-menu-list .nav-menu-list-item {
  font-size: 25px;
  padding: .3em 0;
}
.nav-menu .nav-menu-list .nav-menu-list-item a {
  color: #fff;
}

.animated {
  animation-duration: 1s;
  animation-fill-mode: both;
}

@keyframes bounceInUp {
  from, 60%, 75%, 90%, to {
    animation-timing-function: cubic-bezier(0.215, 0.610, 0.355, 1.000);
  }

  from {
    opacity: 0;
    transform: translate3d(0, 3000px, 0);
  }

  60% {
    opacity: 1;
    transform: translate3d(0, -20px, 0);
  }

  75% {
    transform: translate3d(0, 10px, 0);
  }

  90% {
    transform: translate3d(0, -5px, 0);
  }

  to {
    transform: translate3d(0, 0, 0);
  }
}
@keyframes bounceOutDown {
  20% {
    transform: translate3d(0, 10px, 0);
  }

  40%, 45% {
    opacity: 1;
    transform: translate3d(0, -20px, 0);
  }

  to {
    opacity: 0;
    transform: translate3d(0, 2000px, 0);
  }
}