main.css

html, body, #container {
    width:100%;
    height:100%;
    margin:0;
    padding:0;
}

* {
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

/* Fallbacks in case browser doesn't support vw/vh units
   These are the same measurements used on iPhone */
h1 {
    font-size:32px;
}
#moreinfo {
    font-size:25px;
}
#answer {
    font-size:96px;
}
#answer.y {
    font-size:160px;
}
#answer.n {
    font-size:256px;
}

body {
    font-family: Oswald, sans-serif;
    background-color:#0AB0F7;
    color:white;
}

#container {
    display: table;
}

#info {
    display: table-row;
    vertical-align: bottom;
    height: 1px;
}

h1 {
    font-size:5.5vw;
    text-align:center;
    line-height:1em;
    margin-top:0;
    margin-bottom:0;
    font-weight:400;
}

#answer {
    margin:0;
    font-size:30vh;
    text-align:center;
    font-weight:300;
    line-height:1em;
    text-transform:uppercase;
}
#answer.y, #answer.n {
    font-size:50vh;
    font-weight:700;
}
#answer.y {
    color:green;
    font-size:50vh;
    font-weight:700;
}
#answer.n {
    color:red;
}

#moreinfo {
    margin:0;
    font-size:8vh;
    text-align:center;
}

@media (max-width:700px), (orientation:portrait) {
    h1 {
        font-size:10vw;
    }
    #moreinfo {
        font-size:8vw;
    }
    #answer {
        font-size:30vw;
    }
    #answer.y {
        font-size:50vw;
    }
    #answer.n {
        font-size:80vw;
    }
    #moreinfo {
        margin-top:10vw;
    }
}

/* Fallback since vw/vh is bugged on iPhone */
@media (max-width: 321px) and (min-width:319px){
    h1 {
        font-size:32px;
    }
    #moreinfo {
        font-size:25px;
    }
    #answer {
        font-size:96px;
    }
    #answer.y {
        font-size:160px;
    }
    #answer.n {
        font-size:256px;
    }
    #info {
        margin-top:32px;
    }
}