uniapp界面，不知道是不是bug

这是我 pages.json

{  
    "leftWindow": {  
        "path": "pages/winleft/left.vue",  
        "style": {  
            "width": "350px",  
            "background":"#74aa9d"  
        }  
    },  
    "topWindow": {  
        "path": "pages/wintop/top.vue",  
        "style": {  
            "height": "60px",  
            "background":"#5a6baa",  
            "width":"1190px"  
        }  
    },  
    "pages": [ //pages数组中第一项表示应用启动页，参考：https://uniapp.dcloud.io/collocation/pages  
        {  
            "path": "pages/index/index",  
            "style": {  
                "navigationBarTitleText": "Hello uniapp"  
            }  
        }  
    ],  
    "globalStyle": {  
        "pageOrientation": "portrait",  
        // "navigationStyle":"custom",  
        "navigationBarTitleText": "Hello uniapp",  
        "navigationBarTextStyle": "white",  
        "navigationBarBackgroundColor": "#007aff",  
        "backgroundColor": "#3351f8",  
        "backgroundColorTop": "#F4F5F6",  
        "backgroundColorBottom": "#F4F5F6",  
        "h5": {  
            "maxWidth": 1190,  
            "navigationBarTextStyle": "black",  
            "navigationBarBackgroundColor": "#435af1"  
        }  

    }  
}

页面正常，如图

但是我的首页高度一旦超过整个屏幕，就会发生错乱，如图

下面是我 首页的代码

<template>  
    <view class="content">  
        <view class="a">  
            5564545  

        </view>  

    </view>  
</template>  

<script>  
    export default {  
        data() {  
            return {  
                title: 'Hello'  
            }  
        },  
        onLoad() {  

        },  
        methods: {  

        }  
    }  
</script>  

<style>  
    .a{  
        height: 1000px;  
    }  
    .content {  
        display: flex;  
        flex-direction: column;  
        align-items: center;  
        justify-content: center;  
    }  

</style>