Input focus
We remove the default outline styles on some form controls and apply a box-shadow in its place for :focus.
Disabled inputs
Add the disabled attribute on an input to prevent user input and trigger a slightly different look.
Disabled fieldsets
Add the disabled attribute to a $lt;fieldset$gt; to disable all the controls within the $lt;fieldset$gt; at once.
Validation states
Bootstrap includes validation styles for error, warning, info, and success messages. To use, add the appropriate class to the surrounding .control-group.