feat: update the background of section4; refs #50

Author: elainefan331

src/pages/Home.tsx

@@ -124,7 +124,10 @@ const Home: React.FC = () => {
           zIndex: "2",
           position: "relative",
           width: "100%",
-          backgroundColor: Colors.lightGray,
+          // backgroundColor: Colors.purple,
+          backgroundImage: `url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='100%25' height='100%25' viewBox='0 0 1200 800'%3E%3Cdefs%3E%3CradialGradient id='a' cx='0' cy='800' r='800' gradientUnits='userSpaceOnUse'%3E%3Cstop offset='0' stop-color='%2371feed'/%3E%3Cstop offset='1' stop-color='%2371feed' stop-opacity='0'/%3E%3C/radialGradient%3E%3CradialGradient id='b' cx='1200' cy='800' r='800' gradientUnits='userSpaceOnUse'%3E%3Cstop offset='0' stop-color='%23abb2f9'/%3E%3Cstop offset='1' stop-color='%23abb2f9' stop-opacity='0'/%3E%3C/radialGradient%3E%3CradialGradient id='c' cx='600' cy='0' r='600' gradientUnits='userSpaceOnUse'%3E%3Cstop offset='0' stop-color='%231fa0f6'/%3E%3Cstop offset='1' stop-color='%231fa0f6' stop-opacity='0'/%3E%3C/radialGradient%3E%3CradialGradient id='d' cx='600' cy='800' r='600' gradientUnits='userSpaceOnUse'%3E%3Cstop offset='0' stop-color='%23FFFFFF'/%3E%3Cstop offset='1' stop-color='%23FFFFFF' stop-opacity='0'/%3E%3C/radialGradient%3E%3CradialGradient id='e' cx='0' cy='0' r='800' gradientUnits='userSpaceOnUse'%3E%3Cstop offset='0' stop-color='%2302DEC4'/%3E%3Cstop offset='1' stop-color='%2302DEC4' stop-opacity='0'/%3E%3C/radialGradient%3E%3CradialGradient id='f' cx='1200' cy='0' r='800' gradientUnits='userSpaceOnUse'%3E%3Cstop offset='0' stop-color='%235865F2'/%3E%3Cstop offset='1' stop-color='%235865F2' stop-opacity='0'/%3E%3C/radialGradient%3E%3C/defs%3E%3Crect fill='url(%23a)' width='1200' height='800'/%3E%3Crect fill='url(%23b)' width='1200' height='800'/%3E%3Crect fill='url(%23c)' width='1200' height='800'/%3E%3Crect fill='url(%23d)' width='1200' height='800'/%3E%3Crect fill='url(%23e)' width='1200' height='800'/%3E%3Crect fill='url(%23f)' width='1200' height='800'/%3E%3C/svg%3E")`,
+          backgroundAttachment: "fixed",
+          backgroundSize: "cover",
           padding: "5rem 7rem",
           display: "flex",
           flexDirection: "column",