less 定义值写法

@color:#f66;
@commonMargin:30px;
@baseFontSize:12px;
@articleHeaderFont:24px;

header{
    width: 100%;
    height: 50px;
    background-color:@color;
}
article{
    margin-top:@commonMargin;
    z-index: 10;
    header{
        background-color: #ccc;
    }
    &:hover{
        color:#fff;
        font-size:@articleHeaderFont;
        &.special{
        font-size:48px;
    }
    } 
}