ant-design/components/back-top/demo/custom.md

zh-CN

可以自定义回到顶部按钮的样式，限制宽高：40px * 40px。

注意：BackTop 需要一个可接受 onClick 事件的元素作为 children。 如果您直接将文本作为子项放置，则该组件将无法正常运行。

en-US

You can customize the style of the button, just note the size limit: no more than 40px * 40px.

Note: BackTop expects a element could accept onClick property as children. If you put a text directly as children the component will not function properly.