Fix orientation bugs in default site-template

Maintain fontsize and and adapt width when switching to landscape mode.

In my case on an iPhone 5S.

**Portrait mode**:

![Portrait mode](http://f.cl.ly/items/2P2F1c2c0x3Q2y10252I/portrait.png)

**Landscape before**:

![Landscape before](http://f.cl.ly/items/402R3H143K0J1i002b0N/landscape-before.png)

**Landscape after**:

![Landscape after](http://f.cl.ly/items/3z271p121z0z2a3e0o3y/landscape-after.png)