Slow text appear fullscreen effect.

Fullscreen text show.

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Animation Text</title>
    <link rel="stylesheet" href="style.css">
    <style type="text/css">
    *{
  padding: 0;
  margin: 0;
  font-family: sans-serif;
}
body{
  background: #000;
}
.container{
  text-align: center;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%,-50%);
  width: 100%;
}
.container span{
  text-transform: uppercase;
  display: block;
}
.text1{
  color: white;
  font-size: 60px;
  font-weight: 700;
  letter-spacing: 8px;
  margin-bottom: 20px;
  background: black;
  position: relative;
  animation: text 3s 1;
}
.text2{
  font-size: 30px;
  color: #6ab04c;
}

@keyframes text {
  0%{
    color: black;
    margin-bottom: -40px;
  }
  30%{
    letter-spacing: 25px;
    margin-bottom: -40px;
  }
  85%{
    letter-spacing: 8px;
    margin-bottom: -40px;
  }
}

    </style>
  </head>
  <body>

<div class="container">
  <span class="text1">I Welcome  you.</span>
  <span class="text2">Rahul Gupta</span>
</div>



  </body>
</html>