/* create an arrow that points up */ 
div.arrow-up { 
    width: 0;  
    height: 0;  
    border-left: 5px solid transparent;  /* left arrow slant */ 
    border-right: 5px solid transparent; /* right arrow slant */ 
    border-bottom: 5px solid #2f2f2f; /* bottom, add background color here */ 
    font-size: 0; 
    line-height: 0; 
} 

/* create an arrow that points down */ 
div.arrow-down { 
    width: 0;  
    height: 0;  
    border-left: 5px solid transparent; 
    border-right: 5px solid transparent; 
    border-top: 5px solid #2f2f2f; 
    font-size: 0; 
    line-height: 0; 
} 

/* create an arrow that points left */ 
div.arrow-left { 
    width: 0;  
    height: 0;  
    border-bottom: 5px solid transparent;  /* left arrow slant */ 
    border-top: 5px solid transparent; /* right arrow slant */ 
    border-right: 5px solid #2f2f2f; /* bottom, add background color here */ 
    font-size: 0; 
    line-height: 0; 
} 

/* create an arrow that points right */ 
div.arrow-right { 
    width: 0;  
    height: 0;  
    border-bottom: 5px solid transparent;  /* left arrow slant */ 
    border-top: 5px solid transparent; /* right arrow slant */ 
    border-left: 5px solid #2f2f2f; /* bottom, add background color here */ 
    font-size: 0; 
    line-height: 0; 
}