element-plus/website/demo-styles/slider.scss

.demo-block.demo-slider .source {
  padding: 0;
}

.demo-block.demo-slider .block {
  padding: 30px 24px;
  overflow: hidden;
  border-bottom: solid 1px var(--el-border-color-base);
  &:last-child {
    border-bottom: none;
  }
}

.demo-block.demo-slider .demonstration {
  font-size: 14px;
  color: var(--el-text-color-secondary);
  line-height: 44px;
}

.demo-block.demo-slider .demonstration + .#{$namespace}-slider {
  float: right;
  width: 70%;
  margin-right: 20px;
}