.container{display:flex;flex-direction:row;flex-wrap:wrap}.number{width:40px;height:auto;border:1px solid #000;margin:3px;background:#dcdcdc;border-radius:3px;text-align:center;vertical-align:middle}.prime{background:green;font-size:big;font-weight:700}.multiple{background:#000;color:grey}#app{font-family:Avenir,Helvetica,Arial,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;text-align:center;color:#2c3e50;margin-top:60px}.footer{bottom:0;width:100%;height:60px;line-height:60px;background-color:#f5f5f5}