style.css

html, body{
    height: 100%;
}

body{
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
}

#container{
    width: 100%;
    display: inline-block;
}

#inputContainer{
    width: 30%;
    margin: 0 auto;
}

#input{
    margin-bottom: 5px !important;
}

h3{
    width: 30%;
    display: block;
    margin: 0 auto 5px auto;
    text-align: center;
}

h2{
    width: 50%;
    display: block;
    margin: 1em auto 0 auto !important;
    text-align: center;

    opacity: 0;

    transition: opacity 1s ease-in-out;
    -webkit-transition: opacity 1s ease-in-out;
    -moz-transition: opacity 1s ease-in-out;
    -ms-transition: opacity 1s ease-in-out;
    -o-transition: opacity 1s ease-in-out;
}

img{
    display: block;
    width: 20%;
    margin: 0 auto 10px auto;
}