selected square border

[Louvois]

It is not a bug, but it seems still a decoration problem
When a square is highlighted, is it possible to reduce the size of the border thickness ?

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: gnome-sudoku 1:3.2.1-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-13.21-generic 3.0.6
Uname: Linux 3.0.0-13-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 1.23-0ubuntu3
Architecture: amd64
Date: Tue Oct 25 12:21:32 2011
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
ProcEnviron:
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-games
UpgradeStatus: Upgraded to oneiric on 2011-10-04 (21 days ago)