Button inline style
<button data-type="save" class="editor-email-button" style="background-color: #902052; padding: 0 15px; color: #ffffff; border: 0px; border-radius: 6px; width: 100%; box-sizing: border-box; height: 40px; background-size: auto 100%; cursor: pointer; transition: background 300ms; font-size: 1.6rem;" type="submit" name="save">Register!</button>