任何只要赋予了.btn这个类的Dom对象会自动继承默认样式：圆角灰色按钮。除此之外，BootStrap也提供了其他的样式选项，如下表所示：
|
类名 |
描述 |
颜色 |
实例 |
|
btn |
Default/ Standard button. |
White |
<button type=”button”>Default Button</button> |
|
btn-primary |
Identifies the primary action . |
Blue |
<button type=”button”>Primary Button</button> |
|
btn-success |
Indicates a successful action. |
Green |
<button type=”button”>Success Button</button> |
|
btn-warning |
Indicates caution. |
Yellow |
<button type=”button”>Warning Button</button> |
|
btn-danger |
Indicates a dangerous action. |
Red |
<button type=”button”>Danger Button</button> |
|
btn-link |
Making a button look like link. |
Blue |
<button type=”button”>Link Button</button> |