input[type="checkbox"]{
    -webkit-appearance: none;
    vertical-align:middle;
    margin-top:0;
    background:#fff;
    border:#999 solid 1px;
    border-radius: 3px;
    min-height: 12px;
    min-width: 12px;
}
input[type="checkbox"]:checked {
    background: #3190e8;
}
input[type=checkbox]:checked::after{
    content: '';
    top: 3px;
    left: 3px;
    position: absolute;
    background: transparent;
    border: #fff solid 2px;
    border-top: none;
    border-right: none;
    height: 6px;
    width: 10px;
    -moz-transform: rotate(-45deg);
    -ms-transform: rotate(-45deg);
    -webkit-transform: rotate(-45deg); 
    transform: rotate(-45deg);
}