CSS file for animating with Keyframes extension without using the extension

styleWithoutExtension.css

body{
    background: #f1f1f1;
    font-family: 'Montserrat', sans-serif;
    margin: 0;
}

.container{
    background: rgb(103, 170, 89);
    padding: 5em;
    color: #fff;
}

h1{
    font-size: 4em;
}

p{
    font-size: 2em;
    line-height: 1.6em;
}

a.button{
    display: inline-block;
    padding: .5em;
    background: rgb(242, 255, 196);
    border-radius: 20px;
    color: rgb(103, 170, 89);
    text-decoration: none;
    margin-top: 10px;
    font-size: 1.3em;
    font-weight: bold;
}