Added a :hover border around CodeMirror, so it's easier to see its edges after it's been resized on any color background.
Added a :hover border around CodeMirror, so it's easier to see its edges after it's been resized on any color background.

QingchaoHu/glsl-sandbox,beni55/glsl-sandbox,mrdoob/glsl-sandbox,mrdoob/glsl-sandbox,beni55/glsl-sandbox,RobertoMalatesta/glsl-sandbox,RobertoMalatesta/glsl-sandbox,mrdoob/glsl-sandbox,oresmus/glsl-sandbox,CortesHub/glsl-sandbox,QingchaoHu/glsl-sandbox,RobertoMalatesta/glsl-sandbox,oresmus/glsl-sandbox,CortesHub/glsl-sandbox,beni55/glsl-sandbox,QingchaoHu/glsl-sandbox,oresmus/glsl-sandbox,CortesHub/glsl-sandbox,mrdoob/glsl-sandbox