body {
  margin: 0;
  background-color: #f3f3f3;
}
a{
    text-decoration: none; /* 去掉下划线 */
}
.container {
  width: 70%;
  margin: 0 auto;
}
.padding-30 {
  padding: 30px;
}
.flex-sbw {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.flex-ard {
  display: flex;
  justify-content: space-around;
  align-items: center;
}
.flex-center {
  display: flex;
  justify-content: center;
  align-items: center;
}
.div-relative,
.x-popup,
.app-popup,
.header-btn,
.footer-popup {
  position: relative;
}
.x-popup,
.app-popup,
.footer-popup,.header-btn {
   cursor: default;
}
.popup-app {
  position: absolute;
  top: 30px;
  left: 0px;
}
.popup-customer {
  position: absolute;
  top: 46px;
  left: 0px;
}
.popup-x {
  position: absolute;
  right: -45px;
  bottom: -230px;
}
.app-popup:hover .popup {
  display: block;
}
.header-btn:hover .popup {
  display: block;
}
.x-popup:hover .popup {
  display: block;
}
.line {
  width: 1px;
  height: 23px;
  background: #e3ebff;
  border-radius: 1px;
  opacity: 0.3;
}
button {
  border: none;
}
.header-box {
  background: url("../image/banner.png") no-repeat center center;
  background-size: cover;
  width: 100%;
  height: 700px;
}
.title-box-posi {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 84px;
  background-color: rgba(255, 255, 255, 0.3);
  font-size: 20px;
  color: #ffffff;
}
.title-box{
    height: 100%;
}
.header-img {
  height: 100%;
  display: flex;
  align-items: center;
}
.header-center {
  width: 50%;
}
.header-btn {
  width: 128px;
  height: 44px;
  background:rgba(255, 255, 255, 0.5);
  border-radius: 6px;
  line-height: 44px;
  text-align: center;
  font-weight: 400;
  font-size: 20px;
  color: #333333;
}
.banner-content-box {
  width: 100%;
  position: absolute;
  top: 10%;
  left: 0;
  color: #fff;
  text-align: center;
}
.big-size {
  font-weight: 800;
  font-size: 72px;
}
.yellow {
  color: #f8ff3d;
}
.banner-center-text {
  font-weight: 400;
  font-size: 36px;
  margin: 30px 0 80px 0;
}
.banner-btn-box {
  padding: 0 20%;
}
.banner-content-btn {
  width: 268px;
  height: 62px;
  border-radius: 12px;
  color: #fff;
  font-size: 24px;
}
.teacher-btn-sty {
  background: #3d74ff;
}
.student-btn-sty {
  background: #3bba4d;
}
.banner-bom-img-box {
  position: absolute;
  bottom: -70px;
  left: 0;
  width: 100%;
}
.banner-bom-img {
    width: 100%;
  height: auto;
}
.img-box {
  margin-top: 130px;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.img-item {
  width: 100%;
  margin-bottom: 130px;
}
.auth-box {
  height: 254px;
  background: #3d74ff;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
}
.auth-text {
  font-size: 36px;
  color: #ffffff;
}
footer {
  background: #001d3a;
  padding: 30px 0 10px 0;
  color: #fff;
  min-height: 17rem;
}
.footer-left{
    height: 215px;
}
.footer-div {
  height: 80%;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
}
.footer-title {
  font-size: 24px;
  margin-bottom: 30px;
}
.footer-line {
  position: absolute;
  bottom: -10px;
  left: 0;
  width: 20px;
  height: 2px;
  background: #ffffff;
}
.footer-left-p {
  font-size: 18px;
  padding-top: 20px;
}
.footer-center-p {
  font-size: 18px;
}
.shu-img {
  width: 1px;
  height: auto;
}
.heng-img {
  width: 100%;
  height: auto;
}
.code-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  width: 140px;
  height: 200px;
}
.code-item-right {
  display: flex;
  flex-direction: column;
  align-items: center;
  height: 80%;
  margin-right: 30px;
}
.code-img-box {
  width: 110px;
  height: 110px;
  border-radius: 12px;
  background-color: #fff;
  padding: 10px;
  overflow: hidden;
  margin-bottom: 25px;
}
.code-img {
  width: 100%;
  height: 100%;
}
.footer-bom-text {
  font-size: 12px;
  color: #ffffff;
  opacity: 0.5;
  text-align: center;
}
.fixed-box {
  position: fixed;
  right: 0;
  top: 50%;
}
.fixed-img {
    width: 62px;
    height: auto;
}
.popup {
  width: 15rem;
  height: 15rem;
  background-color: #fff;
  display: none;
  padding: 10px;
  border-radius: 12px;
  z-index: 999;
}
.fixed-popup {
  position: absolute;
  right: 70px;
  top: 0;
}

.footer-popup:hover .popup {
  display: block;
}

@media (min-width: 576px) {
  .container {
    max-width: 540px;
  }
  .fixed-img {
    width: 32px;
}
}
@media (min-width: 768px) {
  .container {
    max-width: 720px;
  }
  .fixed-img {
    width: 42px;
}
}
@media (min-width: 992px) {
  .container {
    max-width: 960px;
  }
  .fixed-img {
    width: 52px;
}
}
@media (min-width: 1200px) {
  .container {
    max-width: 1180px;
  }
  .fixed-img {
    width: 62px;
}
}