Add this code to the Custom CSS field on the Style tab of your Reviews widget’s settings:
[class*="Carousel__CarouselArrowControlContainer-sc"]:first-child {
left: -45px;
}
[class*="Carousel__CarouselArrowControlContainer-sc"]:last-child {
right: -45px;
}
[class*="Main__Container-sc"] {
padding: 0 45px;
}