Project: styled-components
Task (easy): 1) Create components/Header.tsx fixed on the top of the page, with 'Hello Blog' as its text. 2) Create components/Footer.tsx fixed on the bottom of the page 3) Create components/Main.tsx which occupies the remaining space, with 'Welcome to Blog System' as its text 4) Add className 'site-header' to Header, 'site-footer' to Footer, 'site-main' to Main. 5) Import and render Header, Main, Footer in App.tsx 6) Constraint: use styled-components to set appealing style for Header、Footer