how do i draw a vertical line below my vertical hyperlink? html css

Solution 1:

just create a column flex-box and align items to the center.

.line {
  height: 20px;
  width: 4px;
  background: red;
}

.flex-wrapper {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: max-content;
}
<div class="flex-wrapper">
  <a href="">hyperlink</a>
  <div class="line" />
</div>