@media screen and (min-width: 786px) {
  header {
    width: 100%;
    height: 90px;
    position: fixed;
    background: orange;
    top: 0;
    left: 0;
    z-index: 99;
  }

  .header-container {
    display: -webkit-box;
    display: -webkit-flex;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-pack: justify;
    -webkit-justify-content: space-between;
    -ms-flex-pack: justify;
    justify-content: space-between;
    -webkit-box-align: center;
    -webkit-align-items: center;
    -ms-flex-align: center;
    align-items: center;
    max-width: 1200px;
    margin: auto;
    line-height: 90px;
    height: 100%;
  }

  .header-container .logo img {
    width: 160px;
    height: 100%;
    display: block;
  }

  .header-container nav {
    text-align: right;
    display: -webkit-box;
    display: -webkit-flex;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-pack: end;
    -webkit-justify-content: flex-end;
    -ms-flex-pack: end;
    justify-content: flex-end;
    color: #fff;
  }

  .nav-li {
    height: 50px;
    line-height: 50px;
  }

  .nav-item {
    color: #fff;
    text-decoration: none;
    display: inline-block;
    padding: 0 5px;
    margin: 0 25px;
    font-size: 16px;
    text-align: center;
  }

  .nav-yesgo,
  .nav-news {
    height: 90px;
  }

  .nav-yesgo:hover .child {
    display: block;
  }

  .nav-yesgo:hover .nav-item {
    border-bottom: 2px solid #fff;
  }

  .nav-news:hover .child {
    display: block ;
  }

  .nav-news:hover .nav-item {
    border-bottom: 2px solid #fff;
  }

  .child {
    display: none;
    position: absolute;
    top: 100px;
    background: #1a1a1a;
    width: 140px;
    margin: 0;
    list-style: none;
    text-align: center;
    padding: 0;
  }

  .child::before {
    content: "";
    position: absolute;
    top: -10px;
    left: 55px;
    width: 0;
    height: 0;
    border-left: 13px solid transparent;
    border-right: 13px solid transparent;
    border-bottom: 15px solid #1a1a1a;
  }

  .child li {
    margin: 0 30px;
  }

  .child li:nth-child(n + 2){
    border-top: 1px solid #fff;
  }

  .child li a {
    color: #fff;
    font-size: 14px;
  }

  .nav-item-active {
    border-bottom: 2px solid #fff;
  }

  .nav-item:hover {
    border-bottom: 2px solid #fff;
  }

  .menu-toggle {
    display: none !important;
  }

  .phone-menu {
    display: none;
  }

  footer {
    background-color: #1a1a1a;
    width: 100%;
    color: #fff;
    text-align: left;
    padding: 55px 0;
    overflow: hidden;
  }

  .footer-box {
    width: 1100px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
  }
  .contact-us .title,
  .join-us .title {
    font-size: 22px;
  }
  .contact-us .title-english {
    font-size: 14px;
  }
  .contact-us .list {
    padding-top: 26px;
  }
  .contact-us .item {
    font-size: 14px;
    line-height: 30px;
  }

  .contact-us .item a {
    color: #fff;
    margin: 0 10px;
  }

  .join-us .title-english {
    font-size: 14px;
  }
  .join-us .code-path {
    width: 95px;
    height: 95px;
    margin-top: 8px;
  }

  .back-top {
    position: fixed;
    right: 30px;
    bottom: 20%;
    width: 50px;
    height: 50px;
    line-height: 45px;
    color: #fff;
    font-size: 20px;
    border-radius: 50%;
    text-align: center;
    vertical-align: top;
    background-color: #000;
    cursor: pointer;
    z-index: 999;
  }

}

@media screen and (max-width: 785px) {
  header {
    position: fixed;
    width: 100%;
    left: 0;
    top: 0;
    right: 0;
    z-index: 99;
  }

  main {
    padding-top: 70px;
  }

  .nav-li {
    display: none;
  }

  .nav-item {
    position: relative;
  }

  .header-container {
    background-color: orange;
    height: 70px;
    line-height: 70px;
    display: flex;
    justify-content: space-between;
  }

  .header-container .logo img {
    width: 130px;
    vertical-align: middle;
  }

  .menu-toggle,
  .menu-close {
    color: #fff;
    position: absolute;
    top: 18px;
    right: 20px;
  }

  .phone-menu {
    width: 50%;
    height: 100%;
    position: fixed;
    right: -100%;
    top: 0;
    background-color: #000;
    padding-bottom: 10px;
    z-index: 99;
    transition: all 0.3s;
    padding-top: 70px;
  }

  .phone-menu-item {
    display: block;
    text-align: center;
    color: #fff;
    text-decoration: none;
    display: flex;
    justify-content: space-between;
    padding: 20px;
    align-items: center;
  }

  .phone-menu-item i {
    font-size: 20px;
  }

  .phone-menu-cover {
    width: 100%;
    height: 100%;
    position: fixed;
    left: 0;
    top: 0;
    background-color: rgba(0, 0, 0, 0.4);
    display: none;
  }

  .yesgo-child,
  .news-child {
    display: none;
    width: 100%;
    background-color: #fff;
  }

  .yesgo-child a,
  .news-child a {
    width: 100%;
    color: #1a1a1a;
  }

  footer {
    background-color: #1a1a1a;
    width: 100%;
    color: #fff;
    text-align: left;
    padding: 55px 0;
    overflow: hidden;
  }

  .footer-box {
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    padding: 0 20px;
  }
  .contact-us .title,
  .join-us .title {
    font-size: 22px;
  }
  .contact-us .title-english {
    font-size: 14px;
  }
  .contact-us .list {
    padding-top: 26px;
  }
  .contact-us .item {
    font-size: 14px;
    line-height: 30px;
  }

  .contact-us .item a {
    color: #fff;
    display: block;
  }

  .join-us {
    margin-top: 30px;
  }

  .join-us .title-english {
    font-size: 14px;
  }
  .join-us .code-path {
    width: 95px;
    height: 95px;
    margin-top: 8px;
  }

  .back-top {
    position: fixed;
    right: 30px;
    bottom: 10%;
    width: 50px;
    height: 50px;
    line-height: 45px;
    color: #fff;
    font-size: 20px;
    border-radius: 50%;
    text-align: center;
    vertical-align: top;
    background-color: #000;
    cursor: pointer;
    z-index: 999;
  }

  /* 有趣人类行动栏目隐藏 */
  .phone-menu-item:nth-child(5) {
    display: none;
  }
}