.teaching-space-dark-btn {
    width: auto;
    height: 32px;
    border: 1px solid rgba(255, 255, 255, 0.5);
    background: rgba(255, 255, 255, 0.12);
    box-sizing: border-box;
    color: rgba(255, 255, 255, 0.7);
    text-align: left;
    line-height: 30px;
    border-radius: 100px;
    margin-right: 20px;
    font-size: 14px;
    float: right;
    padding-right: 10px;
    margin-top: 6px;
}

.teaching-space-dark-btn:hover {
    border: solid 1px #F5F5F5;
    background: rgba(255, 255, 255, 0.2);
    color: #fff;
}

.teaching-space-dark-btn i {
    float: left;
    width: 14px;
    height: 14px;

    background: url('../../images/course/teaching-space-icon-dark.png') no-repeat;
    background-size: 100%;
    margin-top: 9px;
    margin-left: 12px;
    margin-right: 4px;
}


.teaching-space-dark-btn:hover i {
    background: url('../../images/course/teaching-space-icon-darkHover.png') no-repeat;
    background-size: 100%;
}