To solve the first problem, I've decided to divide the page into grid of 250x250 tiles. This seemed like the simplest solution overall, without turning the page into unmanagable mess. It would be extremely cool to let people have a sort of free canvas, but unfortunately I never managed to actually think of any system that would allow doing this safely and anyhow performantly.
Зарина Дзагоева。业内人士推荐体育直播作为进阶阅读
，这一点在体育直播中也有详细论述
Последние новости，更多细节参见爱思助手下载最新版本
Let’s imagine a world where Alice needs to access some website or “Resource”. In a standard non-anonymous authentication flow, Alice needs to be granted authorization (a “credential”, such as a cookie) to do this. This grant can come either from the Resource itself (e.g., the website), or in other cases, from a third party (for example, Google’s SSO service.) For the moment we should assume that the preconditions for are not private: that is, Alice will presumably need to reveal something about her identity to the person who issues the credential. For example, she might use her credit card to pay for a subscription (e.g., for a news website), or she might hand over her driver’s license to prove that she’s an adult.