html,
body {
  position: relative;
  width: 100%;
  height: auto;
  font-size: 16px;
  font-family: "Microsoft YaHei";
}
/*版心*/
.w1200 {
  width: 1200px;
  margin: 0 auto;
}
/*头部*/
header {
  width: 100%;
  height: 109px;
  background: url(../images/nav_bg.png) no-repeat;
  background-size: 100% 100%;
}
header .nav {
  display: flex;
  justify-content: space-evenly;
  align-items: center;
  height: 100%;
}
header .nav li {
  width: 214px;
  height: 69px;
  background: url(../images/nav_icon.png) no-repeat;
}
header .nav li:hover {
  background: url(../images/nav_icon_on.png) no-repeat;
}
header .nav li:hover a {
  color: #fff;
}
header .nav li a {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
  height: 100%;
  color: #263fa7;
  font-size: 24px;
  font-weight: bold;
}
header .nav .nav_active {
  background: url(../images/nav_icon_on.png) no-repeat;
}
header .nav .nav_active a {
  color: #fff;
}
/*banner*/
.banner {
  width: 100%;
}
.banner img {
  width: 100%;
  height: 100%;
}
/*内容*/
article {
  padding-top: 55px;
  padding-bottom: 35px;
  background-size: 100% 100%;
}
/*版权*/
footer {
  width: 100%;
  height: 100px;
  color: #fff;
  font-size: 14px;
  line-height: 100px;
  text-align: center;
  background: linear-gradient(#b7c2f7, #6d6bc7);
}