Blockly CSS fixes.
Blockly CSS fixes.

Fixes bbc/microbit-extras#1850

jle33/TouchDevelop,SoftwareEngineeringToolDemos/FSE-2012-TouchDevelop,jle33/TouchDevelop,SoftwareEngineeringToolDemos/FSE-2012-TouchDevelop,jle33/TouchDevelop,SoftwareEngineeringToolDemos/FSE-2012-TouchDevelop,SoftwareEngineeringToolDemos/FSE-2012-TouchDevelop,SoftwareEngineeringToolDemos/FSE-2012-TouchDevelop,SoftwareEngineeringToolDemos/FSE-2012-TouchDevelop,SoftwareEngineeringToolDemos/FSE-2012-TouchDevelop,jle33/TouchDevelop,jle33/TouchDevelop