message: make modal width more responsive
diff: .modal-content {
  - position: absolute;
  - top: 20%;
  - left: 50%;
  + min-width: 300px;
  + max-width: 65%;
  + margin: 100px auto 0 auto;
  outline: 0;
  -webkit-overflow-scrolling: touch;
  }
  .modal {
  color: #4d4d4d;
  - position: relative;
  - left: -50%;
  background: white;
  border: 1px solid #dedede;
  border-radius: 4px;
  color: #4d4d4d;
  }
  +.modal .right {
  + display: flex;
  +}
  +
  .modal .right .btn {
  margin-right: 0;
  }
  