How to style a checkbox using CSS

Answer 1

input[type=checkbox].css-checkbox {
    position: absolute;
    overflow: hidden;
    clip: rect(0 0 0 0);
    height: 1px;
    width: 1px;
    margin: -1px;
    padding: 0;
    border: 0;
}

input[type=checkbox].css-checkbox + label.css-label {
    padding-left: 20px;
    height: 15px;
    display: inline-block;
    line-height: 15px;
    background-repeat: no-repeat;
    background-position: 0 0;
    font-size: 15px;
    vertical-align: middle;
    cursor: pointer;
}

input[type=checkbox].css-checkbox:checked + label.css-label {
    background-position: 0 -15px;
}

.css-label{
    background-image:url(http://csscheckbox.com/checkboxes/dark-check-green.png);
}