Theming supports multiple button styles that can be used to indicate the
purpose or importance of a button. The available styles are: primary,
secondary, danger, success, warning, and info. Each
style has its own visual appearance, which can be defined in the theme's
CSS. By using different styles, you can create a visual hierarchy and guide
users' attention to important actions or information on your
website. Additionally, theme can provide more styles for buttons. Usually
additional styles either available via non-standard value for the style
parameter(e.g., style="outline-primary"), or via standard style
combined with non-standard attribute variant(e.g., style="primary",
variant="outline")