Cloudflare Full Strict HTTPS flow


I would like to understand Cloudflare full(strict) SSL flow. Because if user type https://example.com it redirects to Cloudflare web servers. So how Cloudflare decrypt HTTPS data before sending to origin host without browser warning ? How Cloudflare match certificate data between Browser and Cloudflare servers. Because main certificates situated on origin web server and only Original web server can decrypt after get HTTPS data.