[PyGame] Need help understanding some code

[menator01]

I've been practicing with classes a little with some code I found.
The original code was not in a class so that is my project to put it in one.
Every thing works but, I can't seem to get the ball to bounce off the wall on the x axis. They go behind the zero marker and the window length.
On a side note the ball kinda jumps a little too.
Any guidence would be great. Thanks

import pygame
from random import randrange

pygame.init()

clock = pygame.time.Clock()

win_size = [600, 400]

#ball_color = (randrange(256), randrange(256), randrange(256))
ball_color = (255, 0, 0)
ball_size = 20 #randrange(8, 20)
pos = [0, 100]
vel = [1, 1]

class Ball:
    def __init__(self, ball_color, ball_size, pos, vel, win_size):
        self.ball_color = ball_color
        self.ball_size = ball_size
        self.pos = pos
        self.vel = vel
        self.win_size = win_size

    def move(self):

        self.pos[0] += vel[0]
        if self.pos[0] <= self.ball_size:
            self.vel[0] = self.vel[0] + 1

        if self.pos[0] >= self.win_size[0] - self.ball_size:
            self.vel[0] = self.vel[0] - 1

        self.pos[1] += self.vel[1]
        if self.pos[1] <= self.ball_size:
            self.vel[1] = self.vel[1] + 1

        if self.pos[1] >= self.win_size[1] - self.ball_size:
            self.vel[1] = self.vel[1] - 1

def world(ball):
    win = pygame.display.set_mode((win_size[0], win_size[1]))
    win.fill((180, 180, 180))
    pygame.draw.circle(win, ball_color, (pos[0], pos[1]), ball_size)
    ball.move()
    pygame.display.update()


def main():

    ball = Ball(ball_color, ball_size, pos, vel, win_size)

    while True:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()

        world(ball)
        clock.tick(60)
if __name__ == "__main__":
    main()

[menator01]

I found the problem. Thanks