#nav {
  width: 1000px;
  height: 40px;
  margin: 0 auto;
  padding: 0;
  display: flex;
}
#nav li {
  position: relative;
  list-style: none;
}
#nav li a {
  display: block;
  width: 250px;
  height: 40px;
  text-align: center;
  color: #FFF;
  font-size: 14px;
  line-height: 2.8;
  background: #334775;
  text-decoration: none;
}
#nav li a:hover {
  color: #FFF;
  background: #4c6bb1;
}
#nav > li li:hover > a {
  background: #637ebc;
}
#nav li ul {/*�q*/
  top: 40px;
  left: -40px;
  position: absolute;
}
#nav li ul li {
  overflow: hidden;
  height: 0;
}
#nav li ul li a {
  border-top: 1px solid #FFFFFF;
}
#nav li:hover > ul > li {
  overflow: visible;
  height: 40px;
}
  #nav li ul li ul {/*��*/
    top: 0;
    left: 110px;
  }
  #nav li ul li ul:before {/*�q?*/
    position: absolute;
    content: "";
    top: 15px;
    left: 30px;
    border: 5px solid transparent;
    border-left: 5px solid #fff;
  }
  #nav li ul li ul li:hover > a,/*��*/
  #nav li ul li ul li ul li:hover > a {/*�Б�*/
    background: #FEF8D8;
  }
  #nav li ul li ul.left {/*����*/
    top: 0;
    left: -190px;
  }
  #nav li ul li ul.left:before,/*�q��?*/
  #nav li ul li ul li ul.left:before {/*����?*/
    position: absolute;
    content: "";
    top: 15px;
    left: 190px;
    border: 5px solid transparent;
    border-right: 5px solid #fff;
  }
  #nav li ul li ul.left li:hover > a,/*��*/
  #nav li ul li ul li ul.left li:hover > a {/*�Б�*/
    background: #EB5E33;
  }
.content {
  width: 1000px;
  height: 200px;
  background: #eee;
  margin: 0 auto;
  padding: 10px;
  text-align: left;
  box-sizing: border-box;
}