body {
    background-color:#353631
}

p {
    border-style: solid;
}

div {
    width: 350px;
    height: 100px;
    background: lightgray;
    position: relative;
    margin: 20px;
  }
  
  div:after {
    content: '';
    width: 60px;
    height: 4px;
    background: gray;
    position: absolute;
    bottom: -4px;
}