.h3-line {
      display: inline-block;      /* width fits the text */
      position: relative;
      padding-right: 10px;        /* optional space between text and line */
      margin-bottom: 0px;
      margin-top: 50px;
    }

    .h3-line::after {
      content: "";
      position: absolute;
      top: 50%;                   /* vertically center the line */
      left: 100%;                 /* start at the end of the text */
      height: 2px;                /* thickness of the line */
      width: 25%;               /* stretch to the right edge of viewport */
      background: black;          /* line color */
    }