Implement a traffic-light UI with JS

Frontend Coding: Traffic Light

Build a simple traffic light component using HTML + CSS + JavaScript.

Requirements

• Render a vertical traffic light with three circles : red, yellow, green.
• Exactly one light is “on” at a time (brighter color); the others are “off” (dimmed).
• The light should cycle automatically in this order:
  1. Red for R milliseconds
  2. Green for G milliseconds
  3. Yellow for Y milliseconds
  4. Repeat
• Provide a simple way to start the cycle when the page loads (e.g., window.onload ).

Optional extensions (if time)

• Add Start / Pause / Reset controls.
• Allow changing R/G/Y durations without reloading.
• Ensure timers don’t stack (no multiple overlapping intervals/timeouts).

Deliverable

• A single HTML page (or separate HTML/CSS/JS files) that demonstrates the cycling traffic light in a browser.