Vertical Navigation Bar with Animated Markers

Create a vertical navigation bar for a website with the following features: A thin vertical line on the left, with evenly spaced short horizontal lines extending from it, representing navigation markers. When a section is selected, the corresponding horizontal line should expand smoothly outward, with a vibrant accent color animation (e.g., blue). Add hidden section labels near each horizontal line that appear on hover with a smooth fade-in effect. Include dummy scrollable sections for demonstration, and highlight the active section's marker as the user scrolls. Style the navbar with a dark background, light gray lines, and clean, modern typography for labels.