Classy CSS3 Grid

css3-grid.css

.grid {
    width: 100%;
    height: 100%;
    background-color: white;
    background: radial-gradient(circle, transparent 20%, white 20%, white 80%, transparent 80%, transparent),
                radial-gradient(circle, transparent 20%, white 20%, white 80%, transparent 80%, transparent) 0 0,
                linear-gradient(#ddd 1px, transparent 1px) 0 -0.5px,
                linear-gradient(0, #ddd 1px, transparent 1px) -0.5px 0;
    background-size: 20px 20px, 40px 20px, 10px 10px, 10px 10px;
}