.web-menu-box {
  position: absolute;
  top: 70px;
  left: 0;
  width: 100%;
  z-index: 10;
  background: #1e49a5;
  display: none;
}
.web-menu-box li {
  line-height: 45px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.4);
}
.web-menu-box li a {
  display: block;
  color: #fff;
  padding: 0 0.5rem;
  margin-right: 2rem;
}
.web-menu-box li i {
  float: right;
  height: 2rem;
  width: 2rem;
  background: url(../images/arrt.png) no-repeat center;
  background-size: 0.625rem 0.625rem;
  position: relative;
  z-index: 1;
  cursor: pointer;
}
.web-menu-box li .sub {
  display: none;
}
.web-menu-box li .sub a {
  border-top: 1px solid rgba(255, 255, 255, 0.4);
  margin-right: 0;
  background-color: var(--main-color);
  padding-left: 15px;
}
.web-menu-box li.open i {
  background-image: url(../images/arrb.png);
}
.web-menu-box li.open .sub {
  display: block;
}