.required:after {
    content: " *";
    color: red;
}

input.invalid,
select.invalid {
    border-color: red;
}

span.invalid {
    color: red;
    font-size: 12px;
}

#progress-bar {
    margin: 20px 0 30px 0;
    overflow: hidden;
    color: lightgrey;
    padding: 0;
}

    #progress-bar .active {
        color: #000;
        background: linear-gradient(180deg, rgba(0,0,0,0) calc(35% - 1px), green calc(35%), rgba(0,0,0,0) calc(35% + 1px) );
    }

    #progress-bar li {
        list-style-type: none;
        font-size: 12px;
        width: 33.3%;
        float: left;
        position: relative;
        text-align: center;
        background: linear-gradient(180deg, rgba(0,0,0,0) calc(35% - 1px), rgba(192,192,192,1) calc(35%), rgba(0,0,0,0) calc(35% + 1px) );
    }

    #progress-bar #progress-bar-detail:before {
        font-family: FontAwesome;
        content: "\f023";
    }

    #progress-bar #progress-bar-payment:before {
        font-family: FontAwesome;
        content: "\f09d";
    }

    #progress-bar #progress-bar-confirm:before {
        font-family: FontAwesome;
        content: "\f00c";
    }

    #progress-bar li:before {
        width: 50px;
        height: 50px;
        line-height: 45px;
        display: block;
        font-size: 18px;
        color: #ffffff;
        background: lightgray;
        border-radius: 50%;
        margin: 0 auto 10px auto;
        padding: 2px;
    }

    #progress-bar li.active:before,
    #progress-bar li.active:after {
        background: green;
    }