You can use some simple code to override the heading line height, giving you more control.
Simply click the code button.
Select “site-theme.css.”
Scroll to the very bottom and paste the following block. Edit the pixel value as desired.
h1 *
{
line-height:40px !important;
}
Note: you can use this code for other headings.
Click Save and refresh the editor to give it a chance to load in the new style.