How can I place close button outside of modal window in react-modal?

I've imported Modal from react-modal (React Player is just for emdebbing video) and my code looks this way now:

<Modal
    isOpen={modalIsOpen}
    onRequestClose={closeModal}
    style={customStyles}
    contentLabel='Example Modal'
  >
    <button onClick={closeModal} className={css.button}>close</button>
    <ReactPlayer
      url='https://vimeo.com/49384334'
      playing='true'
      controls='true'
      volume={0}
    />
  </Modal>

So I tried to write some styles for button like that, but the button can't leave it's parent tag.

.button {
   display: block;
   float: right;
   position: relative;
   top: -10px;
   right: -10px;
   z-index: 1002;
 }

Are there any styles I should overwrite maybe in the modal div?

By default Modal component from react-modal has overflow: auto. That is why your button can't move outside the modal. To fix this you need change overflow: auto to overflow: visible (see code below)

const modalStyles = {
    content : {
      top                   : '50%',
      left                  : '50%',
      right                 : 'auto',
      bottom                : 'auto',
      marginRight           : '-50%',
      transform             : 'translate(-50%, -50%)',
      overflow              : 'visibile'
    }
  };
const buttonStyles = {
  position: "absolute",
  top: "10px",
  right: "10px"
};

<Modal
  isOpen={this.state.isOpen}
  onRequestClose={this.handleOpenModal}
  style={modalStyles}
  contentLabel="Example Modal"
>
  <button onClick={this.handleOpenModal} style={buttonStyles}>
    close
  </button>
  modal content
</Modal>

Thank you.