Safari takes a while to initialize `document.styleSheets`, which
results in a race condition when loading the pad. Avoid the race
condition by accessing the CSSStyleSheet objects directly from the
HTMLStyleElement DOM objects.
Normally I would let `eslint --fix` do this for me, but there's a bug
that causes:
const x = function ()
{
// ...
};
to become:
const x = ()
=> {
// ...
};
which ESLint thinks is a syntax error. (It probably is; I don't know
enough about the automatic semicolon insertion rules to be confident.)
