fix: 修复 SKills 没有 css 知识的问题

Author: Alexzjt

.gitignore

@@ -42,3 +42,4 @@ yarn-error.log*
 # OS
 .DS_Store
 Thumbs.db
+.history

skills/antv-s2-expert/SKILL.md

@@ -63,3 +63,11 @@ When a user asks about S2 development:
 2. Read the corresponding reference file(s) for context
 3. Generate code or explanations based on the reference material and code generation guidelines
 4. Always provide complete, runnable code examples when possible
+
+## CSS Import Paths
+
+When generating code that requires importing built-in styles, you MUST use the following exact paths (do not omit `/dist/` or use fake paths):
+- Vanilla S2: `import '@antv/s2/dist/s2.min.css';`
+- React Components: `import '@antv/s2-react/dist/s2-react.min.css';`
+- React Advanced Components: `import '@antv/s2-react-components/dist/s2-react-components.min.css';`
+- Vue Components: `import '@antv/s2-vue/dist/s2-vue.min.css';`