Mobile first with CSS flexbox, relative and absolute positioning

The project is mostly complete but I have some things that I could not done as in design files:

• On the slider thumb in the design files, there are different cursors on hover and thumb grabbing. I put cursor: grabbing; property on it and works for grabbing but on hover it did nothing. Can someone help me with this ?
• For the background of the slider I used linear-gradient and changed it from JS but it doesn't look so good. Could someone give any advice on how to build it better ?

If someone could help me with the questions above or with general advice on how good I used margins, padding and positioning it would be great. Any other feedback is appreciated !