node_modules/material-design-lite/src/grid/snippets/grid-demo.html

<style>
.demo-grid .mdl-cell {
  box-sizing: border-box;
  background-color: #BDBDBD;
  height: 200px;
  padding-left: 8px;
  padding-top: 4px;
  color: white;
}
.demo-grid .mdl-grid:first-of-type .mdl-cell {
  height: 50px;
}
</style>

{% include "grid.html" %}