box shadow 1px code example
Example: box shadow 1px
box-shadow: 0 -1px 0 0 red; /* Border top */
box-shadow: 1px 0 0 0 red; /* Border right */
box-shadow: 0 1px 0 0 red; /* Border bottom */
box-shadow: -1px 0 0 0 red; /* Border left */
box-shadow: 0 0 0 1px red; /* All the borders by using the spread properties */