REGULAR BUTTONS:

.button.button-primary
.button.button-primary[disabled]
.button.button-secondary
.button.button-secondary[disabled]
.button.button-critical
.button.button-critical[disabled]
.button.button-borderless
.button.button-borderless[disabled]

ICON VERSION:

.button.button-primary
.button.button-primary[disabled]
.button.button-primary
.button.button-primary[disabled]

BLOCK VERSION:

.button.button-primary.block
.button.button-primary[disabled].block

LARGE VERSION:

.button.button-primary.large
.button.button-primary[disabled].large
.button.button-borderless.large
.button.button-borderless[disabled].large


SMALL VERSION:

.button.button-primary.small
.button.button-primary[disabled].small
.button.button-secondary.small
.button.button-secondary[disabled].small
.button.button-borderless.small
.button.button-borderless[disabled].small
.button.button-critical.small
.button.button-critical[disabled].small

TOOLBAR BUTTONS:

.button.button-toolbar

.button.button-toolbar[disabled]

SMALL TOOLBAR BUTTONS:

.button.button-toolbar.small

DISABLED SMALL TOOLBAR BUTTONS:

.button.button-toolbar[disabled].small

LINK BUTTONS:

.button.button-link
.button.button-link[disabled]

SMALL LINK BUTTONS:

.button.button-link.small
.button.button-link[disabled].small

Theme customization

You can customize some styles using the following css variables