/* back to top */
#myBtnTOP{display:none;position:fixed;bottom:30px;right:30px;z-index:1000;font-size:18px;border:none;outline:none;cursor:pointer;border-radius:4px; padding-top:10px;}
#myBtnTOP:hover{opacity:.7;}
.myBtnTOP-circle{width:40px;height:40px;text-align:center;font-size:12px;line-height:1.42;border-radius:15px;}
.huuguu-btn-primary{color:#fff;background-color:#007bff;border-color:#007bff}
.huuguu-btn-secondary{color:#fff;background-color:#6c757d;border-color:#6c757d}
.huuguu-btn-success{color:#fff;background-color:#28a745;border-color:#28a745}
.huuguu-btn-danger{color:#fff;background-color:#dc3545;border-color:#dc3545}
.huuguu-btn-warning{color:#212529;background-color:#ffc107;border-color:#ffc107}
.huuguu-btn-info{color:#fff;background-color:#17a2b8;border-color:#17a2b8}
.huuguu-btn-light{color:#000;background-color:#f8f9fa;border-color:#f8f9fa}
.huuguu-btn-dark{color:#fff;background-color:#343a40;border-color:#343a40}