4. Given the function
$$
f(x)=\left\{\begin{array}{ll}
2^{2-x}, & x<2 ; \\
\log _{3}(x+1), & x \geqslant 2 .
\end{array}\right.
$$

If the equation $f(x)=m$ has two distinct real roots, then the range of the real number $m$ is $\qquad$ (express in interval form).
4. $(1,+\infty)$.

As shown in Figure 6, the graphs of the functions $y=f(x)$ and $y=m$ are plotted in the same Cartesian coordinate system. It is easy to see that when $m>1$, the equation $f(x)=m$ has two distinct real roots.