chosen-bootstrap.css

/*
 *    add this to your own css file,
 *    to overwrite the _chosen_ styling, to look more like bootstrap!
 *    
 *    note: for the error part to work, an .error class-name must be added
 *    to a wrapping DIV, to display the bootstrap error styling. I have
 *    just use the wrapping .control-group DIV
 *    
 *    credit: Rasmus Burkal, @rabu81
 *            Drew Miller, @mewdriller
*/
ul.chzn-choices {
    -webkit-transition: border linear 0.2s, box-shadow linear 0.2s;
       -moz-transition: border linear 0.2s, box-shadow linear 0.2s;
        -ms-transition: border linear 0.2s, box-shadow linear 0.2s;
         -o-transition: border linear 0.2s, box-shadow linear 0.2s;
            transition: border linear 0.2s, box-shadow linear 0.2s;
}
div.error div.controls div.chzn-container ul.chzn-choices {
    border-color: #B94A48;
}
div.error div.controls div.chzn-container-active  ul.chzn-choices {
    -webkit-box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075), 0 0 8px rgba(185, 74, 72, 0.6);
       -moz-box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075), 0 0 8px rgba(185, 74, 72, 0.6);
            box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075), 0 0 8px rgba(185, 74, 72, 0.6);
}
div.controls ul.chzn-choices {
    border-color: #ccc;
    -webkit-border-radius: 3px;
       -moz-border-radius: 3px;
            border-radius: 3px;
}
div.chzn-container-active  ul.chzn-choices {
    border-color: rgba(82, 168, 236, 0.8);
    -webkit-box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075), 0 0 8px rgba(82, 168, 236, 0.6);
       -moz-box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075), 0 0 8px rgba(82, 168, 236, 0.6);
            box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075), 0 0 8px rgba(82, 168, 236, 0.6);
}
div.chzn-container a.chzn-single {
    font-size: 14px;
    line-height: 20px;
    height: 24px;
    padding-top: 4px;
}
div.chzn-container a.chzn-single div b {
    background-position: 0 2px;
}
div.chzn-container-active a.chzn-single-with-drop div b {
    background-position: -18px 3px;
}
div.chzn-container-single div.chzn-search input {
    border: 1px solid #aaa;    
    font-size: 13px;
    line-height: normal;
    height: auto;
    -webkit-border-radius: 0;
       -moz-border-radius: 0;
            border-radius: 0;
    -webkit-transition: none;
       -moz-transition: none;
        -ms-transition: none;
         -o-transition: none;
            transition: none;
    -webkit-box-shadow: none;
       -moz-box-shadow: none;
            box-shadow: none;
}
div.chzn-container {
    margin-bottom: 10px;
}
div.chzn-container-multi {
    margin-bottom: 5px;
}
div.chzn-container-multi ul.chzn-choices li.search-choice {
    font-size: 14px;
    line-height: 14px;
}