Problem scenario
If you use 100vh in safari or chrome on mobile, a scroll bar appears.
The root cause
In Safari and Chrome, 100vh refers to the height of the address bar removed, so the scroll bar appears.
The solution
Mobile terminal generally does not consider Chrome browser, the user base is small, if only consider wechat public number development do not need to consider this problem. If you need to consider the user experience of Safari, use 100% instead of 100vh, or use JS instead of 100vh.