#cab {
    justify-content: center;
    align-items: center;
    width: 100%;
    margin-left: auto;
    margin-right: auto;
    display: flex;
    height: 48px;
    overflow: hidden;
    background: repeating-conic-gradient(#fff 0 25%, #000 0 50%) 50% / 48px 48px;


}