Improve the look and feel of the landing page (#518)

Author: brian-rose

landing-page.md

@@ -2,10 +2,37 @@
 
 ## A community learning resource for Python-based computing in the geosciences
 
-<img src="images/pretty-earth.png" alt="Pretty Earth" width="600px">
+[![DOI](https://zenodo.org/badge/338145160.svg)](https://zenodo.org/badge/latestdoi/338145160)
+
+:::{image} images/pretty-earth.png
+:alt: Pretty Earth
+:width: 600px
+:align: center
+:::
 
 This collection covers the foundational skills everyone needs to get started with scientific computing in the open-source Python ecosystem.
 
-<img src="images/logos/ProjectPythia_Logo_Final-01-Blue.svg" alt="Project Pythia logo" height="80px"> _Brought to you by [Project Pythia](https://projectpythia.org), the education working group for [Pangeo](https://pangeo.io)_ <img src="https://raw.githubusercontent.com/pangeo-data/pangeo/master/docs/_static/small_e_logo_cropped.png" alt="Pangeo logo" height="80px">
+:::::{grid} 2 2 2 2
+::::{card}
+:link: https://projectpythia.org
+:::{image} images/logos/ProjectPythia_Logo_Final-01-Blue.svg
+:alt: Project Pythia logo
+:width: 80px
+:align: center
+:::
+::::
 
-[![DOI](https://zenodo.org/badge/338145160.svg)](https://zenodo.org/badge/latestdoi/338145160)
+::::{card}
+:link: https://pangeo.io
+:::{image} https://raw.githubusercontent.com/pangeo-data/pangeo/master/docs/_static/small_e_logo_cropped.png
+:alt: Pangeo logo
+:width: 80px
+:align: center
+:::
+::::
+:::::
+
+:::{div}
+:class: col-page-middle
+_Brought to you by [Project Pythia](https://projectpythia.org), the education working group for [Pangeo](https://pangeo.io)_
+:::