升级 Tailwind CSS 到 v4 并简化构建流程

- 将 input.css 从 v3 的 @tailwind 指令迁移到 v4 的 @import "tailwindcss"
- 删除 tailwind.config.js（v4 不再需要配置文件）
- 删除 package.json（完全使用本地 tailwindcss CLI）
- 重新构建 public/style.css 为 v4 格式
- 添加 Makefile 提供 dev/build/css/css-watch/clean 命令

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Makefile

@@ -0,0 +1,22 @@
+.PHONY: dev build css css-watch clean
+
+dev:
+	@echo "Starting tailwindcss watch and dx serve..."
+	@tailwindcss -i input.css -o public/style.css --watch & \
+	TAILWIND_PID=$$!; \
+	trap 'kill $$TAILWIND_PID 2>/dev/null; exit' INT TERM EXIT; \
+	dx serve
+
+build:
+	@tailwindcss -i input.css -o public/style.css --minify
+	@dx build --release
+
+css:
+	@tailwindcss -i input.css -o public/style.css
+
+css-watch:
+	@tailwindcss -i input.css -o public/style.css --watch
+
+clean:
+	@cargo clean
+	@rm -f public/style.css

input.css

@@ -1,3 +1 @@
-@tailwind base;
-@tailwind components;
-@tailwind utilities;
+@import "tailwindcss";

package.json

@@ -1,18 +0,0 @@
-{
-  "name": "yggdrasil",
-  "version": "1.0.0",
-  "description": "",
-  "main": "index.js",
-  "scripts": {
-    "build:css": "tailwindcss -i input.css -o public/style.css --minify",
-    "watch:css": "tailwindcss -i input.css -o public/style.css --watch",
-    "test": "echo \"Error: no test specified\" && exit 1"
-  },
-  "keywords": [],
-  "author": "",
-  "license": "ISC",
-  "type": "commonjs",
-  "devDependencies": {
-    "tailwindcss": "^3.4.19"
-  }
-}

tailwind.config.js

@@ -1,9 +0,0 @@
-/** @type {import('tailwindcss').Config} */
-module.exports = {
-    darkMode: 'class',
-    content: ['./src/**/*.rs', './index.html'],
-    theme: {
-        extend: {},
-    },
-    plugins: [],
-}