.faq-block>div>div:nth-child(1){
    position:relative;
}
.faq-block>div>div:nth-child(1):after{
    position:absolute;
    content:"+";
    font-size:28px;
    line-height:20px;
    color:white;
    top:0;right:-20px;
}
.faq-block>div>div:nth-child(1).active:after{
    content:"-";
}