.nav_menu {
  width: 200px;
  height: calc(100% - 50px);
  background: #ededed;
  float: left;
  position: fixed;
  left: 0;
  top: 50px;
}
.nav_menu .title {
  margin-left: 20px;
  color: #888888;
  margin-bottom: 7px;
  padding-top: 20px;
  font-size: 14px;
}
.nav_menu .item_menu {
  height: 40px;
  line-height: 40px;
  padding-left: 20px;
  cursor: pointer;
}
.nav_menu .item_menu:hover {
  background: #e1e1e1;
}
.nav_menu .item_menu .icon-ziyuan {
  font-size: 15px;
}
.nav_menu .item_menu span {
  color: #2f2f2f;
  margin-left: 9px;
}