first commit

src/hooks/useTheme.ts

@@ -0,0 +1,29 @@
+import { useState, useEffect } from 'react';
+
+type Theme = 'light' | 'dark';
+
+export function useTheme() {
+  const [theme, setTheme] = useState<Theme>(() => {
+    const savedTheme = localStorage.getItem('theme') as Theme;
+    if (savedTheme) {
+      return savedTheme;
+    }
+    return window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';
+  });
+
+  useEffect(() => {
+    document.documentElement.classList.remove('light', 'dark');
+    document.documentElement.classList.add(theme);
+    localStorage.setItem('theme', theme);
+  }, [theme]);
+
+  const toggleTheme = () => {
+    setTheme(prevTheme => prevTheme === 'light' ? 'dark' : 'light');
+  };
+
+  return {
+    theme,
+    toggleTheme,
+    isDark: theme === 'dark'
+  };
+}