:root {
  heightrole: 16 / 9;
}
body {
  background: #fff;
}
.page_top {
  background-image: url('../image/top_back.png') !important;
}
.page_main {
  max-width: 1000px;
  margin: 10px auto 10px;
  padding: 0 20px;
}
.page_main_menu {
  width: 100%;
  height: 60px;
  line-height: 60px;
  display: flex;
  justify-content: space-around;
  border-bottom: 1px solid #dddddd;
}
.page_main_menu_item {
  padding: 0 10px;
  position: relative;
  cursor: pointer;
}
.page_main_menu_item::before {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: #2191ff;
  transition: width 0.4s ease;
}
.page_main_menu_item:hover::before {
  width: 100%;
}
.select_main_menu_item {
  position: relative;
}
.select_main_menu_item::before {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: #2191ff;
}
.page_main_video {
  width: 100%;
  display: grid;
  grid-template-columns: repeat(3, 33.33%);
  padding: 20px 0 0px;
}
.page_main_video_item {
  width: calc(100% - 10px);
  padding: 5px;
}

.page_main_video_item_img {
  cursor: pointer;
  width: 100%;
  height: 180px;
  /* height: calc(100% - 45px); */
  /* padding-top: 56.25%; */
  overflow: hidden;
  position: relative;
  border-radius: 6px;
}
.page_main_video_item_img::after {
  content: '';
  position: absolute;
  z-index: 12;
  display: none;
  left: calc(50% - 21px);
  top: calc(50% - 21px);
  width: 42px;
  height: 42px;
  transition: display 0.8s ease;
  background-image: url('../image/Vector.png');
}
.page_main_video_item_img:hover::after {
  display: block;
}
.page_main_video_item_img::before {
  content: '';
  position: absolute;
  z-index: 11;
  bottom: 0;
  left: 0;
  top: 0;
  width: 0px;
  height: 100%;
  transition: width 0.4s ease;
  background: rgba(0, 0, 0, 0.4);
}
.page_main_video_item_img:hover::before {
  width: 100%;
}
.page_main_video_item_img img {
  border-radius: 6px;
  width: 100%;
  height: 100%;
  vertical-align: bottom;
}
.page_main_video_item_title {
  font-family: PingFang SC, PingFang SC;
  font-weight: 500;
  font-size: 18px;
  color: #333333;
  text-align: left;
  font-style: normal;
  text-transform: none;
  line-height: 25px;
  padding-bottom: 20px;
  /* padding: 2px 0 15px; */
}

@media (max-width: 468px) {
  .page_main_video {
    grid-template-columns: repeat(2, 50%);
  }
  .page_main_video_item_img {
    height: 120px;
  }
  .page_main_menu_item {
    font-size: 14px;
  }
  .page_main_video_item_title {
    font-size: 12px;
  }
}
@media (min-width: 468px) and (max-width: 768px) {
  .page_main_video {
    grid-template-columns: repeat(2, 50%);
  }
  .page_main_video_item_img {
    height: 150px;
  }
  .page_main_video_item_title {
    font-size: 16px;
  }
}
@media (min-width: 768px) and (max-width: 1092px) {
}
@media (min-width: 1092px) and (max-width: 1387px) {
}
@media (min-width: 1387px) and (max-width: 1920px) {
}
@media (min-width: 1920px) {
}