<div id=cellcontainer>
<div>
<a href=# class="iris hawk left"><span></span></a>
</div>
<div>
<a href=# class="iris marvin"><span></span></a>
</div>
</div>
body { margin: 0; }
div#cellcontainer { width: 500px; border-spacing: 1em; }
div { display: table-cell; vertical-align: middle; padding: 0; }
a.iris, a.iris span { display: block; background-color:rgba(4,78,127,1); width: 120px; height: 120px; border-radius: 50%; color: #000; text-decoration: none; transition: .5s all ease-in;
text-align: center; }
a.iris { display: -webkit-box; position: relative; font-family: "BlueHighway", "Blue Highway", Futura, Arial, sans-serif;
-ms-box-align: center; -ms-box-pack: center;
-webkit-box-align: center; -webkit-box-pack: center;
-moz-box-align: center; -moz-box-pack: center;
display: -moz-box; display: -ms-box;
box-pack: center; box-align: center; display: box;
border: 2px solid black; background-size: cover; }
a.iris span { -webkit-transition: .5s ease-in all; -moz-transition: .5s ease-in all; -ms-transition: .5s ease-in all; -o-transition: .5s ease-in all; transition: .5s ease-in all; font-size: 50px; background-position: center; }
a.iris:hover span { background-color:rgba(4,78,127,0.3); width: 0px; height: 0px; }
a.iris:hover:before { opacity: 1; }
a.marvin, a.marvin span { background-image: url(//demosthenes.info/assets/images/mars.jpg); width: 150px; height: 150px; color: #000; transition: .5s all ease-in; }
a.marvin {
background: url(//demosthenes.info/assets/images/marvin.png), url(//demosthenes.info/assets/images/mars.jpg); border: 2px solid black; background-size: fit; }
a.marvin span { -webkit-transition: .5s ease-in all; -moz-transition: .5s ease-in all; }
a.marvin:hover span { background-color:rgba(4,78,127,0.3); width: 0px; height: 0px; }
a.marvin:hover:before { opacity: 1; }
a.marvin:before { content: "Where's the kaboom?"; position: absolute; text-align: center; top: 170px; opacity: 0; -moz-transition: 1s all linear; -ms-transition: 1s all linear; -webkit-transition: 1s all linear; -o-transition: 1s all linear; transition: 1s all linear; display: block; }
a.hawk { background: url(//demosthenes.info/assets/images/pariah-kite.jpg); background-size: cover; }
a.iris:hover span { background-color:rgba(4,78,127,0.3); width: 0px; height: 0px; }
a.hawk:after { content: "⬅"; position: absolute; top: 65px; left: 30px; color: rgba(255,255,255,0.8); font-size: 60px; line-height: 0; }
a.hawk:hover:before { opacity: 1; }
a.hawk:before { content: "Learn more about hawking"; position: absolute; text-align: center; top: 130px; opacity: 0; -moz-transition: 1s all linear; -ms-transition: 1s all linear; -o-transition: 1s all linear; -o-transition: 1s all linear; transition: 1s all linear; display: block; }
Also see: Tab Triggers