CSS optimisations in the backend

[NetOldie]

Hello,

I noticed 3 small optimisations in the CSS in the backend. At the IDs #sharebox & #copybox the parameter is missing
height: auto;
This makes the share links for Facebook and Twitter visible.

For the ID #shareboxes please set the margin to 0px (currently it is set to -10px). The page margin will then be flush with the table.