1、垂直居中，写在父级上
div{display: flex;justify-content: center;align-items: center;}
2、flex-左右两端，垂直居中 该布局在移动端较为常见
<style>.wrap{display: flex;justify-content: space-between;align-items: center;width: 200px;height: 100px;border: 1px solid #000;}</style><div class="wrap"><p>左边文字</p><p>右边文字</p></div>
3、10个div分两行布局，（保持div原有的宽度）
<style>.wrap{width: 300px;height: 500px;background: pink;}.nav{display: flex;flex-wrap: wrap; /*伸缩盒子的换行*/}.item{width: 20%;border: 1px solid #000;box-sizing: border-box;}</style><div class="wrap"><div class="nav"><div class="item">菜单</div><div class="item">菜单</div><div class="item">菜单</div><div class="item">菜单</div><div class="item">菜单</div><div class="item">菜单</div><div class="item">菜单</div><div class="item">菜单</div><div class="item">菜单</div><div class="item">菜单</div></div></div>
