size of the border css code example
Example: css border length
.page-title:after {
content: ""; /* This is necessary for the pseudo element to work. */
display: block; /* This will put the pseudo element on its own line. */
margin: 0 auto; /* This will center the border. */
width: 50%; /* Change this to whatever width you want. */
padding-top: 20px; /* This creates some space between the element and the border. */
border-bottom: 1px solid black; /* This creates the border. Replace black with whatever color you want. */
}