This does absolutely nothing on firefox, but works great in safari and chrome.
There are tricks to make zooming happen on firefox, but it involves stuff like this
```
html {
-moz-transform: scale(0.7);
-moz-transform-origin: 0 0;
}
@-moz-document url-prefix() {
html {
width: 142.857%;
}
}
```
amd after that some things still have a very hard time staying aligned with the screen edges (such as the sidebar). So I've left that as a future exercise.