Styling pseudo-classes and nested elements with Emotion

In this section, we will learn how to style pseudo-classes with Emotion. We will then move on to learn how to style nested elements:

1. In Header.tsx, implement the following styles on the anchor tag:

   <a
     href="./"
     css={css`
       font-size: 24px;
       font-weight: bold;
       color: ${gray1};
       text-decoration: none;
     `}
   >
     Q & A
   </a>

   Here, we are making the app name fairly big, bold, and dark gray, and also removing the underline.

2. Let's move on and style the search box:

   <input
     type="text"
     placeholder="Search..."
     onChange={handleSearchInputChange}
     css={css`
       box-sizing: border-box;
       font-family: ${fontFamily};
       font-size: ${fontSize...