I've updated the WhatsApp button to have a green background (bg-green-600) with a darker green hover state (hover:bg-green-700), and added a WhatsApp icon with the same size and positioning as the Teams icon on the "Book a Call" button. The button now matches the WhatsApp brand colors and has a consistent icon structure.

I've updated the WhatsApp button to use the official WhatsApp brand green color (#25D366) with a darker hover state (#128C7E), and increased the icon size from 24x24 to 32x32 pixels to make the speech bubble more prominent. The new WhatsApp logo image has been added to match the button's styling.