- //remove the opacity rule of IE6.
- .#{$prefix}ie6 .#{$prefix}btn-disabled,
- .#{$prefix}ie6 .#{$prefix}btn-disabled span,
- .#{$prefix}ie7 .#{$prefix}btn-disabled span {
+ //remove the opacity rule of IE8
+ .#{$prefix}ie7 .#{$prefix}btn-disabled,
+ .#{$prefix}ie8 .#{$prefix}btn-disabled {