.main-nav {
  overflow: hidden;
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 3;
  opacity: 1;
  width: 100%;
  height: 100%;
  transition: all 0.5s;
  visibility: visible;
}
.main-nav.nav-hide {
  width: 1px;
  height: 1px;
  opacity: 0;
  visibility: hidden;
  transition: all 0.5s;
}
.main-nav.nav-hide .nav-box .nav-list {
  opacity: 0;
}
.main-nav .img-cov {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.main-nav .nav-box {
  top: 24px;
  width: 1440px;
  transition: all 0.5s;
}
.main-nav .nav-box .nav-close {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  border: 1px solid #fff;
  cursor: pointer;
}
.main-nav .nav-box .nav-close .lvfaweb {
  color: #fff;
}
.main-nav .nav-box .nav-close:hover {
  background-color: #0F4696;
  border-color: #0F4696;
}
.main-nav .nav-box .nav-list {
  padding-top: 80px;
  opacity: 1;
}
.main-nav .nav-box .nav-list .nav-li h3 {
  color: #fff;
  font-size: 24px;
  margin-bottom: 36px;
  cursor: pointer;
  transition: all 0.5s;
}
.main-nav .nav-box .nav-list .nav-li .nav-item a {
  display: block;
  color: #fff;
  font-size: 18px;
  line-height: 45px;
  display: -webkit-box;
  display: -ms-flexbox;
  display: -webkit-flex;
  display: flex;
  align-items: center;
  transition: all 0.5s;
}
.main-nav .nav-box .nav-list .nav-li .nav-item a::after {
  display: inline-block;
  content: '\e686';
  font-family: 'lvfaweb';
  font-size: 30px;
  opacity: 0;
}
.main-nav .nav-box .nav-list .nav-li .nav-item a:hover::after {
  opacity: 1;
}
@media screen and (max-width: 1450px) {
  .main-nav .nav-box {
    width: calc(100% - 60px);
  }
}
@media screen and (max-width: 992px) {
  .main-nav .nav-box {
    width: calc(100% - 40px);
  }
  .main-nav .nav-box .nav-list .nav-li h3 {
    font-size: 20px;
  }
  .main-nav .nav-box .nav-list .nav-li .nav-item a {
    font-size: 16px;
    line-height: 40px;
  }
}
@media screen and (max-width: 768px) {
  .main-nav .img-cov::after {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: block;
    content: '';
    background-color: rgba(0, 0, 0, 0.2);
  }
  .main-nav .nav-box {
    top: 1em;
    width: calc(100% - 1.5em);
    height: calc(100vh - 2em);
    display: -webkit-box;
    display: -ms-flexbox;
    display: -webkit-flex;
    display: flex;
    -webkit-box-orient: vertical;
    -ms-flex-direction: column;
    -webkit-flex-direction: column;
    flex-direction: column;
  }
  .main-nav .nav-box .logo img {
    max-width: 70%;
  }
  .main-nav .nav-box .nav-close {
    width: 1.5em;
    height: 1.5em;
    border-radius: 50%;
    border: 1px solid #fff;
    cursor: pointer;
  }
  .main-nav .nav-box .nav-close .lvfaweb {
    color: #fff;
  }
  .main-nav .nav-box .nav-close:hover {
    background-color: #0F4696;
    border-color: #0F4696;
  }
  .main-nav .nav-box .nav-list {
    padding-top: 0;
    opacity: 1;
    display: block;
    -webkit-box-flex: 1;
    -ms-flex: 1;
    -webkit-flex: 1;
    flex: 1;
    min-width: 0;
    overflow-y: auto;
  }
  .main-nav .nav-box .nav-list .nav-li h3 {
    color: #fff;
    font-size: 20px;
    margin-top: 1em;
    margin-bottom: .5em;
    padding-top: .5em;
    cursor: pointer;
  }
  .main-nav .nav-box .nav-list .nav-li .nav-item {
    display: flex;
    flex-wrap: wrap;
  }
  .main-nav .nav-box .nav-list .nav-li .nav-item a {
    width: 50%;
    display: block;
    color: #fff;
    font-size: 16px;
    line-height: 40px;
    display: -webkit-box;
    display: -ms-flexbox;
    display: -webkit-flex;
    display: flex;
    align-items: center;
  }
  .main-nav .nav-box .nav-list .nav-li .nav-item a::after {
    display: inline-block;
    content: '\e686';
    font-family: 'lvfaweb';
    font-size: 30px;
    opacity: 0;
  }
  .main-nav .nav-box .nav-list .nav-li .nav-item a:hover::after {
    opacity: 1;
  }
  .main-nav .nav-box .nav-list .nav-li + .nav-li h3 {
    border-top: 1px solid rgba(255, 255, 255, 0.5);
  }
}