Why does pressing harder not change my stroke? +
Pressure-sensitive behavior requires a pointing device and browser combination that reports changing pressure values. If the device supplies no pressure data or repeatedly supplies the same value, the tool has no changing signal to reflect. A compatible stylus is the appropriate input for pressure practice; a mouse remains useful for tracing paths and studying proportions.
Can this replace practicing with a real calligraphy pen? +
No. It can help rehearse stroke shapes, movement, spacing, and pressure control on a screen, but it cannot reproduce nib-to-paper friction, nib orientation, ink flow, paper texture, or absorption. Use the displayed guides and letterforms for controlled rehearsal, then confirm the technique with the pen, ink, and paper intended for the finished work.