grav-lecampus/user/themes/lecampus/scss/theme/_footer.scss

#footer{
  width: 100%;
  background: grey;
  @include inlineflex;
  .sub-content{
    width: calc((100% / 3) - 40px);
    border-top: 1px solid black;
    margin: 20px;
    h3{
      margin-top: 20px;
    }
  }
}