index.wxss

.navbar{
  width: 100%;
  overflow: hidden;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 10;
  flex-shrink: 0;
}
.navbar .nav-content{
  width: 100%;
  box-sizing: border-box;
  height: 32px;
  line-height: 32px;
  text-align: center;
  position: absolute;
  left: 0;
  z-index: 10;
  color: #333;
  font-size: 20px;
  text-overflow: ellipsis;
  overflow: hidden;
  white-space: nowrap;
}