simple sample _partial.scss file. this partial only needs to apply positional styles because all visual styles are driven by @Mixins from a controlled source.

_modal_partial.scss

// simple sample _partial.scss file.
// this partial only needs to apply positional style
// because all visual styles are driven by @mixins from a controlled source.
.modal.form {
  
  form {
    p {
      display: inline-block;
      width: 50%;
      margin: 10px 0;
      padding: 0 5px; } // p

    input { width: 100%; } // input
  } // form

  input[type=submit] {
    float: right;
    margin-right: 5px;
    @include blue-button;
    display: block;
    width: auto; } // input[type=submit]

} // .modal.form