pq-video-mp/src/components/Navbar/index.wxss

.nav-bar .nav-bar-navigation {
  display: flex;
  justify-content: center;
  align-items: center;
  color: #000;
  position: relative;
}
.nav-bar .nav-bar-navigation .back-icon {
  position: absolute;
  left: 40px;
  height: 20px;
  width: 20px;
  border-width: 0 0 4px 4px;
  border-color: #000;
  border-style: solid;
  transform: matrix(0.71, 0.71, -0.71, 0.71, 0, 0);
}