Formatting shiny apps using CSS - but can't find selectors

[jwogle]

I created a shiny app with a sidebar and card. I want to format the title as it appears (set in page_opts) to have a background color that spans the entire page and the title centered, I also want to set the background color of the side bar. I'm using a CSS file but nothing seems to take effect. I think I am not setting the correct CSS selectors but I find no documentation on how to determine which selectors to use for this. Any suggestions?

[nirgrahamuk]

your best friend will be your browsers developer tools / inspector.
on windows with chromium type browser, Ctrl+Shift+ i is the shortcut.
The tab to use is elements

[jwogle]

Thank you for your response. I must be doing something wrong because the selectors don't seem to work. For example, I look at the element for the side bar, which is declared as:

  <aside id="bslib_sidebar_0af946" class="sidebar">

but when I set the CSS for it in the file, it has no effect:

  .sidebar{
      background-color: #e2e3e4;
      font-weight: bold;
      font-family: Arial, Helvetica, sans-serif;
  }

[nirgrahamuk]

If you use the developer tools inspector and investigate the element there is a calculated section you can use to see why a given property , like the background has been chosen, it should list competing rules that were less specific and not applied.

If thats not enough to help you, i think the next step would be for you to provide a reprex.

[jwogle]

This helped a lot. Thank you