v1.0.0

frontend/src/theme/ThemeContext.jsx

@@ -0,0 +1,34 @@
+import { createContext, useContext, useEffect, useState, useCallback } from 'react';
+
+const THEME_KEY = 'ktoco_theme';
+const ThemeContext = createContext(null);
+
+function applyTheme(theme) {
+  const root = document.documentElement;
+  if (theme === 'system') {
+    root.removeAttribute('data-theme');
+  } else {
+    root.setAttribute('data-theme', theme);
+  }
+}
+
+export function ThemeProvider({ children }) {
+  const [theme, setThemeState] = useState(() => localStorage.getItem(THEME_KEY) || 'system');
+
+  useEffect(() => {
+    applyTheme(theme);
+  }, [theme]);
+
+  const setTheme = useCallback((t) => {
+    localStorage.setItem(THEME_KEY, t);
+    setThemeState(t);
+  }, []);
+
+  return <ThemeContext.Provider value={{ theme, setTheme }}>{children}</ThemeContext.Provider>;
+}
+
+export function useTheme() {
+  const ctx = useContext(ThemeContext);
+  if (!ctx) throw new Error('useTheme must be used within ThemeProvider');
+  return ctx;
+}