.triangle(top,@w:15px,@c:pink,@t:transparent,@d:dashed,@s:solid){

border-width:@w;

border-color:@t @t @c @t;

border-style:@d @d @s @d; 

}

.triangle(right,@w:15px,@c:pink,@t:transparent,@d:dashed,@s:solid){

border-width:@w;

border-color:@t @t @t @c;

border-style:@d @d @d @s; 

}

.triangle(bottom,@w:15px,@c:pink,@t:transparent,@d:dashed,@s:solid){

border-width:@w;

border-color:@c @t @t @t;

border-style:@s @d @d @d; 

}

.triangle(left,@w:15px,@c:pink,@t:transparent,@d:dashed,@s:solid){

border-width:@w;

border-color:@t @c @t @t;

border-style:@d @s @d @d; 

}

.triangle(@_,@w:15px,@c:pink){ 

width:0;

height:0;

overflow:hidden;

}

.sanjiao{ 

 .triangle(left,50px)

}

这么写可以吧？那几个英文字母实在是烦