A circle C1 of radius $s$ is drawn in the first quadrant of the $xy$-plane, tangent to both axes. Two circles of radius $s/4$ are drawn: C2 is tangent to C1 and the $x$-axis, and C3 is tangent to C1 and the $y$-axis. A circle of radius $r>s/4$ is tangent to both axes and to C2 and C3. What is $r/s$?