feat: various improvements

- add Terms of Service
- add dark mode
- use cards for blog with excerpt

src/components/atoms/Footer.tsx

@@ -0,0 +1,25 @@
+import { ReactNode } from "react"
+import { Box, useTheme } from "@mui/material"
+
+export type FooterProps = {
+  children: ReactNode
+}
+
+export const Footer = ({ children }: FooterProps) => {
+  const theme = useTheme()
+
+  return (
+    <Box
+      position="fixed"
+      display="flex"
+      bottom={0}
+      padding={2}
+      width="100%"
+      borderTop={`1px solid ${theme.palette.grey[200].toString()}`}
+      gap={2}
+      style={{ backgroundColor: theme.palette.background.default.toString()}}
+    >
+      {children}
+    </Box>
+  )
+}