styles.css

body {
    font: 'Arial', serif;
    color: rgba(0,0,0,.5);
    text-align: center;
    text-transform: uppercase;
    letter-spacing: .5em;
    top: 15%;
	background: linear-gradient(to right, rgb(0, 255, 0) , rgb(0, 255, 255));
}

h1 {
    font: 500 3.5em 'Raleway', sans-serif;
    color: rgba(0,0,0,.5);
    text-align: center;
    text-transform: uppercase;
    letter-spacing: .5em;
    width: 100%;
}

p {
    width: 100%;
    letter-spacing: 0.1em;
    color: rgba(0, 0, 0, 0.699);
    text-transform: none;
}

h3 {
    font: 'Arial', serif;
    width: 100%;
    letter-spacing: 0.1em;
    color: rgba(0, 0, 0, 0.5);
    text-align: center;
    text-transform: uppercase;
}

button {
    width: 50%;
    height: 50px;
    font-family: Helvetica;
    border-bottom: 5px solid steelblue;
    border-top: none;
    border-left: none;
    border-right: none;
    background: linear-gradient(#5FDDFF,#53ADDF);
    color: white;
    border-radius: 10px;
    box-shadow: 0px 2px 10px grey;
    transition: 150ms ease;
    font-weight: bold;
  }
  
  button:active{
    border: none;
    border-bottom: 2px solid steelblue;
    box-shadow: 0px 1px 5px grey;
    background: linear-gradient(#53AFFF,#5FCDFF);
    color: #FFF;
  }
  
  .btn-3d-sub {
    width: 20%;
    height: 30px;
    font-family: Helvetica;
    border-bottom: 5px solid #173814;
    border-top: none;
    border-left: none;
    border-right: none;
    background: linear-gradient(#469e3f,#255b20);
    color: white;
    border-radius: 10px;
    box-shadow: 0px 2px 10px grey;
    transition: 150ms ease;
    text-align: center;
    font-weight: bold;
  }
  
  .btn-3d-sub:active {
    border: none;
    border-bottom: 2px solid steelblue;
    box-shadow: 0px 1px 5px grey;
    background: linear-gradient(#255b20,#469e3f);
    color: #FFF;
  }