You can add custom css for mobile screen

@media (max-width: 767px) {
  .your-container-class {
    width: 100% !important;
    padding-left: 10px;
    padding-right: 10px;
  }
  
  .your-text-class {
    font-size: 16px !important;
    text-align: center !important;
  }
}

Set your font accordingly.