On a modern computer monitor I cannot read dark text on a light background, or any text on a fancy background. I therefore set my browser to use a dark grey background and light grey text, overriding the web designer's choice of colours.
In this forum I find the "buttons" such as Edit are totally invisible, which suggests that they are not real buttons, but are created by manipulating a background image. Is the case? If so, why do you do this, what is wrong with real buttons?