- Basic rounded corner adjustment, changed from unified `2px` to four-level rounded corners, which are `2px``4px``6px``8px` respectively, which are applied to different scenarios, for example, the rounded corners of the default size Button are adjusted to `6px`.
- Main color adjustment, changed from `#1890ff` to `#1677ff`.
- Overall shadow adjustment, from the original three-level shadow adjustment to two levels, which are used for resident page components (such as Card) and interactive feedback (such as Dropdown).
- Deprecated less and adopted CSS-in-JS to better support dynamic themes.
- All less files are removed, and less variables no longer support leaking.
- css files are no longer included in the product. Since CSS-in-JS supports importing on demand, the original `ant-design-vue/dist/antd.css` has also been removed. If you need to reset some basic styles, please import `ant-design-vue/dist/reset .css`.
- If you need to reset the style of the component and don't want to introduce `ant-design-vue/dist/reset.css` to pollute the global style, you can try to use [App component](/components/app), to solve the problem that native elements do not have ant-design-vue specification style.
- Removed css variables and dynamic theme schemes built on top of it.
- LocaleProvider has been deprecated in 3.x (use `<ConfigProvider locale />` instead), we have completely removed the related directories `ant-design-vue/es/locale-provider`, `ant- design-vue/lib/locale-provider`.
-`babel-plugin-import` is no longer supported, CSS-in-JS itself has the ability to load on demand, no longer need plug-in support.
- Remove `xxxl` breakpoint attribute in grid layout. `xxxl` attribute has been removed in v4, you can use [theme customization](/docs/vue/customize-theme) to modify `screen[XS|SM|MD|LG|XL|XXL]` to modify the break Point value achieved.