Start content higher on landing page

[andyjiang3]

Fix #12

[audrey-yang]

Header bar position looks good! Could you change two things?

1. Keep the height of the landing image to be automatic (it's ok if it's a little cut off)
2. Make sure there is no gap between the landing background and bar on smaller screens (same issue as #4)

[andyjiang3]

Header bar position looks good! Could you change two things?

1. Keep the height of the landing image to be automatic (it's ok if it's a little cut off)
2. Make sure there is no gap between the landing background and bar on smaller screens (same issue as For smaller screens, make sure there is no gap between the landing background and nav #4)

I made the following changes. However, when you resize the window, the position of the header doesnt get updated right away, you need to reload the page for the position to update. I tried using useEffect to update it dynamically but the way the image load in and how the ref is set makes it complicated to get the height of the image. Lmk if theres a better way of doing this.

[audrey-yang]

@andyjiang3 Hmm, I think bringing back Joe's change from #4 that used calc and adding min in the css file might work. Let me know if that still doesn't, though.