How to change the styles of inline elements in Grafana?

Question

Sass

We installed grafana, set up sources and dashboards, everything works well. However, the panel titles are too small to be customizable through the Grafana interface. I found an article on Grafana customization - https://www.neteye-blog.com/2017/12/how-to-customi...
Collected from source, started editing _variables.dark.scss according to the manual in the link above. run go build. However, I do not see the effect of the changes when starting the server. The npm run build command included in the tutorial hangs while running.
How can you edit styles in Grafana?..