.toplayer
  button#hi Click Here
.layer
  i#remove.fa.fa-remove
  p Thanks for clicking.
  p Hope you'll have an awesome day!
  a(href="https://twitter.com/sa_sha26", target="_blank") Coded by Sasha Tran
View Compiled
$pink: #ff3466;
$space: #424B54;
@import url('https://fonts.googleapis.com/css?family=Source+Sans+Pro:200,300,400');
* {
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Source Sans Pro', sans-serif;
}

.toplayer {
  z-indeX: 99;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

button {
  background: $pink;
  width: 150px;
  height: 40px;
  border: none;
  color: #FFF;
  border-radius: 6px;
  font-family: 'Source Sans Pro', sans-serif;
  font-size: 15px;
  letter-spacing: 1px;
  outline: none;
  cursor: pointer;
}

.layer {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  z-index: -1;
  position: absolute;
  top: 0;
  width: 100%;
  height: 100vh;
  background: $space;
  opacity: 0;
  transform: scale(0.1);
  font-size: 27px;
  transition: all 0.5s ease;
  > * {
    margin: 3px;
  }
}

i {
  position: absolute;
  right: 15px;
  top: 10px;
  color: #FFF;
  cursor: pointer;
}

p {
  color: #FFF;
  font-size: 20px;
  letter-spacing: 2px;
  font-weight: 300;
  opacity: 0;
  transition: all 3s ease;
}

a {
  opacity: 0;
  font-size: 13px;
  color: $pink;
  letter-spacing: 1px;
  text-decoration: none;
}

.clicked {
  transition: all 0.5s ease;
  transform: scale(1);
  z-index: 100;
  opacity: 1;
  p, a {
    opacity: 1;
  }
}
View Compiled
$("#hi").click(function(){ 
  $(".layer").addClass("clicked");
});

$("#remove").click(function(){
  $(".layer").removeClass("clicked");
})

External CSS

  1. https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.1/jquery.min.js