There is an image, any, preferably background, it is necessary to cut the angle using css tools as if it was implemented through photoshop: here’s an example for a slider 
The trick is that this image is shifting, that is, the typical behavior is left but it will appear completely as on the screen. I am able to cut foty on photoshop, but not an option. I tried through border-top-width but just a duplication of the image takes place, but I just need a bevel, the difficulty is that the background is not uniform, how can this be accomplished? The functionality of the slider does not interest but only the bevel and the image. For example, a monkey but only one angle, the left right - no matter what
