[STYLE CHANGE] Improvise Scroll bar

**Description:**

According to the UI of website scroll bar should need to be changed

**Reason for Change:**

Scroll bar looks like an old versioned.

**Current Styling:**

default scroll bar

**Proposed Styling:**

A thin, colorful & latest updated scroll bar matching with theme of website

**Priority Level (optional):**

- [ ] Low
- [ ] Medium
- [x] High

**Timeline (optional):**
[I just need 10 minutes]