Amanda Seyfried began her career as a teenager riding the bus back and forth between her hometown of Allentown, Pennsylvania and New York City for auditions. Then in 2004, she shot to fame in the hit movie Mean Girls playing the memorably ditzy Karen. In this week’s “Sunday Sitdown,” Willie Geist talks to the star about her career since then, including roles in Mamma Mia! and Les Misérables, and her latest Oscar-nominated performance in the acclaimed film Mank.