Are you using Windows OS?
If so, you can play with existing theme css settings:
- Open your app in desktop Chrome browser.
- Open the myCSS.css file using Notepad.
In the browser, right click on the 'Home' menu button or any other button (eg. query operation button) and select 'Inspect Element'
The browser will now show you the HTML on the bottom left frame & CSS on the right frame. The button is enclosed with a HTML <div> and the CSS on right are for this selected div.
You can select on other HTML tags within that DIV until you get to the 'Home' text. which is enclosed in <span>. select this <span> and on the CSS on the right you can play with the text size settings.
You can change any of the CSS on the right (changes are not permanent) to play with different settings.
Once you have found the ideal style you can then copy that changed CSS setting (eg .x-btn-inner {font-size: 16px !Important;}) and paste that setting in myCSS.css.
Note: use !Important tag after the setting so the system will use your setting instead of the theme's setting.
As you can see you are not modfying the theme CSS directly, you are creating your own amendments stored in myCSS.css. Using this method, you can make amendments to any CSS of the theme you are using.
Create a link to myCSS.css in Startup.html below the
<!-- CSS SEPARATOR. Don't delete --> line
<link rel="stylesheet" type="text/css" href="myCSS.css">