My first KDE Applet

I just finished my first KDE Applet, it displays how many minutes the students in our computer rooms are allowed to surf.
I was impressed how easy it was to implement the I/O and the timer, but I am still fighting with the GUI Layout. Here are two screenshots:
I haven’t managed to use a QVBoxLayout as I originally planned, so I am using static sizes, which sucks because if the taskbar height is reduced, the QLCDNumber keeps its size. The Code is here