css border shorthand

p {
 
border: 5px solid red;
} 

#selector{
    /*The format is border:width style color;*/
    border:2px solid grey;
}

hr {
  border:none;
  border-top:1px dashed #f00;
  color:#fff;
  background-color:#fff;
  height:1px;
  width:50%;
}