To make your text bold and white here is the css
.accordionhover-group:hover{
color: #fff;
font-weight: bold;
}
And the arrow on hover, here is the css that i suggest you to use to achieve the desired effect.
.clicked .accordionhover-group i: hover {
background-position: -311px -99px;
background-image:url("http://tommywebdesigner.com/img/glyphicons-halflings-white.png");
float: right;
}
.clicked .accordionhover-group:hover i {
background-position: -288px -93px;
background-image:url("http://tommywebdesigner.com/img/glyphicons-halflings-white.png");
float:right;
}
.icon-arrow-down-white {
background-position: -311px -99px;
float :right;
margin-top: 5px;
background-image: url("http://tommywebdesigner.com/img/glyphicons-halflings-white.png");
}
.icon-arrow-up-white {
background-position: -288px -93px;
float :right;
margin-top: 5px;
background-image: url("http://tommywebdesigner.com/img/glyphicons-halflings-white.png");
}
Also there is no need to use important after a style.
Here is a good article on the use of important in css
http://css-tricks.com/when-using-important-is-the-right-choice/