Alerts

Alerts подходят для заметных системных сообщений внутри контента. Используй `.alert` и один цветовой модификатор.

This is a primary alert—check it out!
This is a success alert—check it out!
This is a secondary alert—check it out!
This is a info alert—check it out!
This is a warning alert—check it out!
This is a error/danger alert—check it out!
Alerts HTML 
<div class="alert alert-primary">Primary message</div>
<div class="alert alert-success">Operation completed</div>
<div class="alert alert-warning">Check settings</div>
<div class="alert alert-error">Action failed</div>