shorthand border

f you leave out one of the values of a shorthand property, it will cause that value to revert to its initial, or default, stat

by Casiano Rodriguez-Leon

HTML

<div class="example">
    Hello world!
</div>

CSS

.example {
  border-style: dashed;
  border-width: 2px;
  border-color: blue;
}
.example {
  border: solid;
  color: green;
}