.content{
  width: 1200px;
  margin: 0 auto;
}
.nav{
  margin-top: 60px;
  box-sizing: border-box;
}
.nav_ul{
  box-sizing: border-box;
}
.nav_ul li{
  margin-right: 170px;
}
.nav_item{
  cursor:pointer
}

.nav_img{
  width: 88px;
  height: 88px;
}
.nav_img img{
  width: 100%;
  height: 100%;
}
.video{
  width: 1200px;
  margin: 10px auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 20px 0;
  min-height: 100px;
}