jQuery .css() gets or sets the css style property for the target element;
js:
$('.target').css('background-color', 'yellow').append(' <span class="label label-info">set background-color</span>');
$('.target2').css({
'background-color': 'yellow',
'font-weight': 'bold'
}).append(' <span class="label label-info">set background-color and font-weight</span>');
$('.target3').append(' bg-color:' + $('.target3').css('background-color')).append(' <span class="label label-info">get background-color</span>');
html:
<div class="target">.target</div> <div class="target2">.target2</div> <div class="target3">.target3</div>
css:
.target3 {
background-color: #afa;
}