app/node_modules/ng-zorro-antd/back-top/style/index.css

/* stylelint-disable at-rule-empty-line-before,at-rule-name-space-after,at-rule-no-unknown */
/* stylelint-disable no-duplicate-selectors */
.ant-back-top {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  color: rgba(0, 0, 0, 0.85);
  font-size: 14px;
  font-variant: tabular-nums;
  line-height: 1.5715;
  list-style: none;
  font-feature-settings: 'tnum';
  position: fixed;
  right: 100px;
  bottom: 50px;
  z-index: 10;
  width: 40px;
  height: 40px;
  cursor: pointer;
}
.ant-back-top:empty {
  display: none;
}
.ant-back-top-rtl {
  right: auto;
  left: 100px;
  direction: rtl;
}
.ant-back-top-content {
  width: 40px;
  height: 40px;
  overflow: hidden;
  color: #fff;
  text-align: center;
  background-color: rgba(0, 0, 0, 0.45);
  border-radius: 20px;
  transition: all 0.3s;
}
.ant-back-top-content:hover {
  background-color: rgba(0, 0, 0, 0.85);
  transition: all 0.3s;
}
.ant-back-top-icon {
  font-size: 24px;
  line-height: 40px;
}
@media screen and (max-width: 768px) {
  .ant-back-top {
    right: 60px;
  }
  .ant-back-top-rtl {
    right: auto;
    left: 60px;
  }
}
@media screen and (max-width: 480px) {
  .ant-back-top {
    right: 20px;
  }
  .ant-back-top-rtl {
    right: auto;
    left: 20px;
  }
}