Responsive CSS Circles

You don’t need @media queries for this. This is my try, pure CSS:

.x1 {
    overflow:hidden;
}
.x1 .x2 {
    display:block;
    float:left;
    padding: 12.5%;
    width:auto;
    height:auto;
    border-radius:50%;
    -moz-border-radius:50%;
    -webkit-border-radius:50%;
    -khtml-border-radius: 50%;
    background:#eee;
    text-align:center;
    position: relative;
}
.x1 .x2 span {
    position: absolute;
    width: 100%;
    left: 0;
    top: 48%;
    line-height: 1em;
    height: 1em;
    font-size: 100%;
    overflow: hidden;
}​

Fiddle

Full Screen