CSS's "transparent" may not be transparent, especially on diagonal borders You might not realise it, but transparent is defined as rgba(0, 0, 0, 0)—transparent black. In WebKit browsers with no anti-aliasing (I believe they're finally in the process of rectifying this omission), this doesn't matter. However, in browsers with anti-aliasing of diagonal borders (IE9+ and Firefox), this can have serio
