.wrap {
  width: 100%;
  margin: 0 auto;
  overflow: hidden;
}

.cont {
  width: 1200px;
  margin: 0 auto;
}

html,
body {
  margin: 0 auto;
}

p {
  text-align: justify;
  font-size: 16px;
}

a:hover,
a:active,
a:visited,
a:link {
  text-decoration: none;
}

.flex-sb {
  display: flex;
  flex-wrap: nowrap;
  justify-content: space-between;
}

.nav-wrap {
  display: none;
  height: 80px;
  overflow: visible;
  position: fixed;
  top: 0;
  left: 0;
}

.nav-wrap .logo {
  line-height: 80px;
}

.nav-wrap .nav-list {
  display: flex;
  flex-wrap: nowrap;
  justify-content: space-between;
}

.nav-wrap .nav-list a {
  display: block;
  line-height: 80px;
  padding: 0 20px;
  color: #fff;
}

.nav-wrap .nav-list li:hover,
.nav-wrap .nav-list li.active {
  background-color: #5ab5da;
}

.m-nav-btn {
  display: none;
}

@media (max-width: 768px) {
  .wrap {
    max-width: 7.5rem;
    overflow: hidden;
  }

  .wrap .cont {
    width: 6.9rem;
  }

  .nav-wrap {
    height: 1rem;
    overflow: visible;
    z-index: 999;
  }


  .nav-wrap .logo {
    line-height: 1rem;
  }

  .nav-wrap .logo img {
    height: .4rem;
  }

  .nav-wrap .m-nav-btn {
    width: 1rem;
    height: 1rem;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
  }

  .nav-wrap .m-nav-btn span {
    display: block;
    width: 0.6rem;
    height: 0.06rem;
    border-radius: 0.03rem;
    margin: 0.05rem 0;
    background-color: #171c61;
    transition: 500ms;
  }

  .nav-wrap .m-nav-btn.active span:nth-child(1) {
    transform-origin: left;
    transform: rotate(46deg);
    margin-bottom: 0.1rem;
    transition: 500ms;
  }

  .nav-wrap .m-nav-btn.active span:nth-child(2) {
    width: 0;
    transition: 500ms;
  }

  .nav-wrap .m-nav-btn.active span:nth-child(3) {
    transform-origin: left;
    transform: rotate(-46deg);
    margin-top: 0.1rem;
    transition: 500ms;
  }

  .nav-wrap .nav-list {
    display: none;
    position: absolute;
    top: 1rem;
    right: 0;
    background-color: #171c61;
  }

  .nav-wrap .nav-list li {
    list-style: none;
  }

  .nav-wrap .nav-list a {
    display: block;
    line-height: 0.8rem;
    color: #fff;
  }

  .nav-wrap.dark {
    background-color: #171c61;
  }

  .nav-wrap .logo-dark {
    display: none;
  }
  .nav-wrap.dark .logo-light {
    display: none;
  }
  .nav-wrap.dark .logo-dark {
    display: block;
  }

  .nav-wrap.dark .m-nav-btn span {
    background-color: #fff;
  }

}