You can find the Style option in the theme Customizer on Appearance → Customize → General → Global styles.
Customize the style and personalize parts of your website.
Site Background customize background color, whole site background image.
Button customize the style of the button on the whole site.
Form Input customize the style of the Form Input on the whole site.
Heading Title custom styling for headers applied to Modules, Sections,
Related Posts, Comments… all over the site.
Sidebar Widgets (Pro) Customize sidebar styling that applies to all sidebars on the entire site.
Sidebar Widgets Title (Pro) custom style the header located on the sidebar apply with all the classic widgets throughout the site