Check (responsive) design

• Mobile design
• Icons for True/False values
• Group Note in week view
• Personal Notes in separate Tab
• Back to week view in lesson view
• Back to "My students" in person overview
• Tardiness time in lesson view
• Less space on mobil view of week view for lesson status icon
• Tab title "Week overview" to "Lesson documentation"
• Back buttons should include a label
• Align icon of "There are no unexcused lessons." better