html,
body {
  width: 100vw;
  height: 100vh;
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  background: linear-gradient(180deg, #f3f8ff 0%, #dbe3fd 100%), repeat;
}
p {
  margin: 0;
  padding: 0;
}
li,
ol,
ul {
  list-style: none;
  margin-block-start: 0;
  margin-block-end: 0;
  margin-inline-start: 0;
  margin-inline-end: 0;
  padding-inline-start: 0;
}

.page-container .page {
  position: absolute;
  top: 0;
  left: 50%;
  transform: translate(-50%);
  width: 100%;
  height: 100%;
  transition: opacity 0.3s ease;
}

#page-4 {
  width: 1200px;
  height: 100vh;
}

/* page-4 */
.title_img {
  width: 1200px;
  position: fixed;
  z-index: 11;
  margin-top: 40px;
}
.catalog {
  width: 1200px;
  height: 126px;
  background: linear-gradient(135deg, #fceafe 0%, #f9d6ff 100%);
  margin-bottom: 20px;
  border-radius: 32px;
}
.up_title {
  font-weight: 500;
  color: #000000;
  font-size: 20px;
  width: 1200px;
  height: 64px;
  background: #ffffff;
  border-radius: 70px;
  box-shadow: 0px 4px 12px rgba(56, 96, 255, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
}

.down_item_text {
  display: flex;
  align-items: center;
  flex-direction: row;
  margin-top: 18px;
  font-size: 20px;
  margin-left: 48px;
}

.item_p {
  height: 28px;
  margin-right: 40px;
  font-weight: 500;
  line-height: normal;
  cursor: pointer;
  padding-bottom: 5px;
  border-bottom: 1px solid transparent;
  color: #000000;
}

.showOn {
  color: #3860ff;
  font-weight: 500;
  padding-bottom: 5px;
  border-bottom: 1px solid #3860ff;
}

.imgs_scroll {
  width: 1200px;
  margin-top: 186px;
  height: calc(100vh - 186px);
  overflow: auto;
  -ms-overflow-style: none; /* IE & Edge */
  scrollbar-width: none; /* Firefox */
}
.imgs_scroll::-webkit-scrollbar {
  display: none; /* Chrome & Safari */
}
.img_name_box {
  width: 1196px;
  background: #f3f8ff;
  border: 2px solid transparent;
  border-radius: 32px;
  margin-bottom: 21px;
}

.img_name_box > .name {
  text-align: center;
  font-weight: 500;
  color: #000000;
  font-size: 20px;
  width: 1196px;
  height: 64px;
  line-height: 64px;
  background: #ffffff;
  border-radius: 70px;
  box-shadow: 0px 4px 12px rgba(56, 96, 255, 0.2);
}

.img_name_box > .tutorials_img_box {
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 20px 0 30px 0;
}
.tutorials_img_box img {
  margin-left: 40px;
}
.tutorials_img_box-five img {
  margin-left: 20px;
}
.last {
  margin-bottom: 200px;
}
.img_name_box.show {
  border: 2px solid #3860ff;
}
.img_name_box.show .name {
  color: #3860ff;
}