String highlighting fails on a multi-line string

QString mainWindowButtonStyle = "QToolButton { border: 3px solid black; \
                                                                                           border-radius: 6px; \
                                                                                           background-color: white; \
                                                                                           color: black; \
                                                                                           min-width: 300px; \
                                                                                           max-width: 300px; \
                                                                                           min-height: 200px; \
                                                                                           max-height: 200px; \
                                                                                           font: bold 20px; \
                                                                                           font-family: \"Arial\"; } \
                                                                  QToolButton:pressed { background-color: black; \
                                                                                                            color: white; }";