how to remove the bounding box around figure in ggplot2?

I have been trying to make a polar violin plot but seem to get the bounding box. Here is my code and figure:

x <- matrix(runif(n=1000,-pi/2,pi/2),ncol =4 )  
df <- reshape2::melt(x)

df$Var2 <- as.factor(df$Var2)

library(ggplot2)
df |>
  ggplot(aes(
    x = Var2,
    y = value,
    fill = Var2
  )) +
  geom_violin() +
  theme_light() +
  coord_polar() +
  geom_hline(yintercept = 0) +
  guides(fill = "none") +
  theme(
    axis.text.x = element_blank(), axis.ticks.x = element_blank(),
    axis.text.y = element_blank(), axis.ticks.y = element_blank()
  ) +
  labs(x = NULL, y = NULL)

But I get:

How do I get rid of the box around the figure? Thanks!

If I understand you correctly, you want to set panel.border to element_blank(). You can find the available settings for ggplot themes at https://ggplot2.tidyverse.org/reference/theme.html

x <- matrix(runif(n=1000,-pi/2,pi/2),ncol =4 )  
df <- reshape2::melt(x)

df$Var2 <- as.factor(df$Var2)

library(ggplot2)
df |>
  ggplot(aes(
    x = Var2,
    y = value,
    fill = Var2
  )) +
  geom_violin() +
  theme_light() +
  coord_polar() +
  geom_hline(yintercept = 0) +
  guides(fill = "none") +
  theme(
    axis.text.x = element_blank(), axis.ticks.x = element_blank(),
    axis.text.y = element_blank(), axis.ticks.y = element_blank(),
    panel.border = element_blank()
  ) +
  labs(x = NULL, y = NULL)