Conditional probability of an atom from a mixed distribution function

The cumulative distribution function of a random variable $X$ is given by

$$F(x)=\begin{cases}0, & x<0,\ \frac14+\frac16\left(4x-x^2\right), & 0\le x<1,\ 1, & x\ge1.\end{cases}$$

Then $P(X=0|0\le X<1)=$ ___________.